HomeMy WebLinkAboutCT 2017-0003; LA COSTA TOWN SQUARE - PARCEL 3; DRAINAGE REPORT; 2023-02-10
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TABLE OF CONTENTS
Vicinity Map ....................................................................................................................................1
1. Scope of Report ................................................................................................................. 2
2. Existing Site ....................................................................................................................... 2
3. Project Description ........................................................................................................... 2
4. Proposed Hydrology ................................................................................................................. 3
4.1 Design Criteria .......................................................................................................................................... 3
4.2 Soils ........................................................................................................................................................... 3
4.3 Runoff Coefficient (C-Factors) .................................................................................................................. 3
4.4 Rainfall ...................................................................................................................................................... 3
4.5 Time of Concentration ............................................................................................................................... 3
4.6 Peak Flow Rates ........................................................................................................................................ 4
5. Hydrology .......................................................................................................................... 4
6. Detention ............................................................................................................................ 7
7. Inlet Sizing ......................................................................................................................... 8
8. Conclusion ....................................................................................................................... 10
EXHIBITS
A. Hydrology / Hydraulic Summary
B. Inlet Sizing
C. Detention Calculations / Revised Excerpts CT-01-09 Drainage Study
D. SWMM / HMP Documentation
APPENDIX
San Diego County June 2003 Hydrology Manual References
City of Carlsbad Standards
EXISTING DRAINAGE EXHIBIT Map Pocket #1
PROPOSED DRAINAGE EXHIBIT Map Pocket #2
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1. Scope of Report
The scope of this report includes providing hydrology and inlet calculations for the proposed
private storm drain system, and estimated site discharges. The majority of the developed site
discharges to the existing detention basin located west of the site. A separate SWQMP report
(SB&O, Inc. dated July 27, 2022) was prepared for the project.
2. Existing Site
The project site is located on La Costa Avenue and across from Calle Timiteo within the City of
Carlsbad, California. The site was previously graded for anticipated development per DWG.
NO. 474-7A. The runoff from northern slopes (E-3 and E-4) are intercepted by a ditch at the top
of a large anchor retaining wall, then bypass around the pad and discharge into Basin 1 (West).
The existing pad is split down the middle creating separate east and west basins. Runoff is
overland flow to temporary sediment basins (DWG NO. 474-7A). The westerly temporary
sediment basin discharges into Basin 1 located west of the site. The easterly sediment basin
discharges into the existing inlet along La Costa Ave frontage. The runoff from the graded entry
road and southeast slopes are intercepted by a concrete ditch that flows into a third sediment
basin that also discharges into the inlet along La Costa Ave.
The existing detention basin (Basin 1—analyzed and constructed during development of the
northerly adjacent La Costa Town Square project, CT 01-09) west of the site was sized to
accommodate developed conditions flows from approximately 32 acres of comingled
commercial development and offsite street runoff from Rancho Santa Fe Avenue, as well as well
as approximately 2.4 developed acres of Parcel 3. The existing detention basin was designed to
mitigate the regional 100-year storm peak flowrate to a rate that would not exceed the pre-
developed condition. Per the CT 01-09 drainage report, the pre-developed 100-year peak
flowrate was 55 cfs.
See Existing Drainage Exhibit in Map Pocket #1.
3. Project Description
The proposed 7.2 ac project is a multi-level residential development. The development will
include paving, surface parking, common areas, and private storm drain system. Runoff from
the primary development area will be directed to Modular Wetland Systems the proposed
control structure and HMP pipe storage located onsite. The rear graded slope behind the
northern wall will also be directed to Basin 1.
Calculations for this HMP & peak flow mitigation can be found within the Technical
Memorandum for SWMM Modeling for Hydromodification Compliance of La Costa Town
Square (Tory R Walker, dated August 2022) in the project SWQMP.
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See Proposed Drainage Exhibit in Map Pocket #2.
The entry road will be intercepted by two (2) proposed curb inlets near the La Costa Ave
intersection and discharge to the proposed treatment and HMP basin located to the east
(existing temporary sediment basin location).
4. Proposed Hydrology
4.1 Design Criteria
Drainage systems will be designed in accordance with the City of Carlsbad’s “Engineering
Standards,” Chapter 5. The Rational Method as defined in the San Diego County Hydrology
Manual (June 2003 edition) is used to calculate peak flow rates for 100-year storm events. (See
Appendix for Reference Materials, Charts & Tables)
4.2 Soils
The soil mapping for the site is hydrologic soil group Type “D,” used for hydrology calculations.
4.3 Runoff Coefficient (C-Factors)
The runoff coefficients for this project, according to the San Diego County Hydrology Manual
(2003) Table 3-1, includes the following;
Surface Condition % Impervious Runoff Coefficient
Impervious / Paved 100 0.87
Pervious / Slopes 0 0.35
Proposed Site 80 0.79
Proposed Site 85 0.82
4.4 Rainfall
Rainfall intensities are calculated using the rainfall data from the County 6-Hour and 24-Hour
Isopluvial Maps as follows;
Storm
Event
6-Hour
Rainfall
(in)
24-Hour
Rainfall
(in)
Ratio
P6/P24
Adjusted
P6
(in)
100-Year 2.9 5.1 57% 2.9
See Appendix for Isopluvial Maps and Figure 3-1 to determine the adjusted 6-hour rainfall.
4.5 Time of Concentration
Rainfall intensities were calculated using times of concentration in accordance with the
procedures noted in the June 2003 Hydrology manual. This includes the limitations as noted in
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Table 3-2, which restricts the initial overland times of concentration (To) based upon the Land
Use / Density (% Impervious) and slope.
4.6 Peak Flow Rates
Peak flow rates are estimated using the Rational Method (Q=CIA). Rainfall intensities are based
upon the following formula;
I = 7.44 P6 Tc-.645
Where;
P6 is the local 6-hour rainfall total (inches) for a given storm frequency.
Tc is the time of concentration (minutes) at the design location in the drainage system.
Note: When calculating intensity, the minimum Tc is 5 minutes.
5. Hydrology
The Parcel 3 property is part of the much larger La Costa Town Square development which
includes a master detention basin located immediately west of the site that is already operational.
The detention basin was designed to mitigate post development runoff from the entire
development. A detailed analysis and verification of the existing detention basin using the
Parcel 3 development envelope is discussed in Section 6. Analysis of the current hydrologic
condition is not relevant to the detention analyses, which are based upon the pre-development
topography and flow lengths for the entire project.
A simplified comparison of the development areas will document changes to the interim
conditions for Parcel 3. Although the existing site is currently pad graded, the pre-development
condition of the site was moderately to steep ground (natural slopes ranging from 10% to 3:1),
trending north to south with an average overland dimension of about 350 feet. County
Hydrology Manual Table 3-2 limits the initial overland flow length based land use, with a natural
condition is limited to 6.9 minutes for slope of 10% or greater. For comparison purposes, a time
of concentration of 8 minutes will be used for the Pre-development and Existing Conditions.
The 100-year (P6=2.9 mins) intensity for an 8- minute tie of concentration is 5.64 in/hr.
A breakdown of the individual interim areas using the same time-of-concentration is as follows;
Existing Condition Area
(ac)
Runoff
Coefficient
Q100
(cfs)
Upper Slope (E-3, E-4) 0.85 0.35 1.64
West Pad ( E-7, E-8) 1.62 0.35 3.20
To West Detention Basin 2.47 4.88
East Sediment Basin (E-1, E-2) 2.21 0.35 4.36
SE Sediment Basin (E-5 & E-6) 0.99 0.35 1.96
La Costa Ave Storm Drain 3.20 6.32
Total 5.67 0.35 11.20
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Note; The eastern temporary sediment basin is currently connected to the curb inlet and storm
drain system at the east end of the project, which discharges to the La Costa Avenue storm drain
system. The above summary include the areas tributary to the temporary sediment basin and
ignores the existing graded slopes along La Costa Avenue.
See Existing Drainage Exhibit in Map Pocket 1 and Hydrology Summary for the temporary
sediment basins in Exhibit A.
The master drainage plan for the entire La Costa Town Square assumed that the Parcel 3
development area and upper manufactured slope would be directed to west detention basin for
attenuation, along with a portion of the shopping center located to the north.
The project driveway entry and adjacent slopes are conveyed to the southeast temporary
sediment basin, located east of the La Costa intersection, and connected to the existing curb inlet
public storm drain system at the east end of the project. The remaining front slopes were
expected to discharge directly to the La Costa Avenue gutter which is intercepted by the same
existing curb inlet. The hydrology calculations for Parcel 3 development area including the rear
slopes are summarized as follows;
Post Development Condition – West
(Unmitigated)
Area
(ac)
Runoff
Coefficient
Q100
(cfs)
Development Area (MWS #1) 3.86 0.71 17.35
West Access Road (MWS #2) 0.27 0.71 1.19
Rear Slope – Existing Outfall 0.84 0.35 2.25
To West Detention Basin 4.97 20.61
Compare to Current Condition – West 2.47 4.88
Note: The West Access Road area was not included in the current/ interim area.
See Map Pocket #2 for the Proposed Drainage Exhibit, and Exhibit “A” for Hydrology
Calculations (CivilD).
The eastern portion of the site will be directed to a surface biofiltration basin, sized to provide
treatment and HMP mitigation, located east of the main entry at the toe of slope. Due to the
steepness of the paved entry and the short gutter and pipe lengths, it is anticipated that the time
of concentration will be extremely short, with a minimum time of concentration of 5 minutes.
Post Development Condition – East Area
(ac)
Runoff
Coefficient
Q100
(cfs)
Project Entry Drwy & Slope (Basin 2) 1.00 0.46 3.51
To La Costa Storm Drain
Compare to current La Costa Storm Drain 3.20 6.32
The above summary documents a reduction from the interim conditions to the La Costa storm
drain system.
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Treatment (provided by the MWS units) and HMP mitigation (linear underground storage pipe)
will be provide onsite for the western portion of the site. Due to space limitations, a linear
approach to storage was achieved by using oversized storm drain pipes within the main east-west
driveway. A diversion structure is placed at the low point in the driveway, near the intersection
with the main entry driveway. The primary storm drain connected to the main MWS unit was
increased from 18” to 36” in size (approximately 700’ length). The main MWS unit does not
have an internal bypass, which limits the outflows to less than 1.0 cfs. A secondary storm drain
is located above and parallel to the primary storm drain. This secondary “overflow” storm drain
line is nearly level and provides approximately 500 lineal feet of 30” diameter storage with an
outlet control structure at the western end. The diversion structure (essentially a large cleanout)
allows storm runoff to fill the primary storm drain pipe. Restriction by the MWS unit results in
an “overflow” to the upper bypass storm drain. The outlet control structure at the west end of
the secondary storage pipe also restricts flows using a combination of low flow & mid-flow
openings and an overflow weir. Since both the outlet control structure and the MWS restrict
flows, runoff is stored in the lower (36”) & upper (30”) storm drain pipes and the 36” storm
drain located upstream of the diversion cleanout. The size and elevation of the outlet control
openings and weir length were selected to provide HMP mitigation for the Parcel 3 development
area.
The complexity of the system does not allow a standard hydrology computer program to model
the split flow paths, the time lag / velocity reduction provided by storage, or the resulting
distortion of the confluence procedure. The most conservative approach is to perform the CivilD
calculations for the post development condition while ignoring the effects of the flow
restrictions. The results for the development areas tributary to MWS#1 and the Outlet Control
system were as follows;
Post Development Condition Area
(ac)
Runoff
Coefficient
Q100
(cfs)
Development Area (MWS #1 / Outlet Control) 3.86 0.71 17.35
A review of the SWMM modeling input data shows that a combined outflow of 17.35 cfs occurs
when the storage depth reaches 11.1 feet above the outlet elevation of the MWS#1 (276.68). The
corresponding storage elevation is 287.78, which results in a submerged condition for the entire
length of the storage pipes. Based upon the SWMM storage & outflow table, the flow through
the MWS unit is 0.9 cfs, with 16.4 cfs passing through the outlet control structure.
Standard detention routing assumes a level water surface where the flow velocity approaches
zero. As noted above, the split design of the storage and outflow controls, the flow rates through
the pipe segments are known. The majority of the 100-year discharge flows through the upper
30” pipe (16.4 cfs) which results in a velocity of 3.34 fps. Although small, the velocity is large
enough to create a friction loss along the length, which implies a sloped water surface.
The control elevation of 287.78 occurs at the overflow weir in the Outlet Control Structure. The
water surface elevation upstream of the control section was modeled a long culvert under a road
crossing using the HY-8 computer program. The required headwater is 288.31 at the upstream
Diversion cleanout structure, which has a rim elevation of 289.86. The flow velocities upstream
I I
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of the Diversion structure are 1.0 fps or less which indicates a nearly level water surface
upstream of the diversion structure. The Diversion structure receives flows from the curb inlets
on either side of the driveway. The critical inlet is on the south side near the intersection with
the main entry drive. The top of curb elevation is 289.54, with a lip of gutter elevation at
288.84, which is 0.53’ above the estimated water surface elevation. The overflow location for
the pipe storage system is this same inlet, which would spill to the west side of the main entry
driveway and flow to the La Costa Avenue gutter.
See SWMM / HMP / HY-8 documentation in Exhibit D.
6. Detention
The project site (Parcel 3) is part of the larger La Costa Town Square development, which was
constructed at a location to the west of the Parcel 3 site. The basin was designed to provide
HMP mitigation for a portion of the adjacent shopping center, and detention for the development
area of Parcel 3 and the shopping center site.
The preliminary design for the Parcel 3 proposed modifications to the existing basin to add
treatment and hydromodification controls for the Parcel 3 site, while maintaining detention for
the entire development.
The final design for Parcel 3 will provide treatment and HMP mitigation onsite before
discharging to the existing detention basin. Two (2) proprietary biofiltration basins (Modular
Wetland Systems by Bioclean) will provide treatment, and a linear oversized storm drain
provides HMP storage using a control structure. The HMP Mitigation for Parcel 3 is
documented in the “Technical Memorandum for SWMM Modeling for Hydromodification
Compliance of La Costa Town Square, dated December 2022” included in the project SWQMP.
This current project proposes to drain approximately 5 acres of the Parcel 3 site to the existing
detention basin. When compared to the original CT 01-09 drainage study, this is an increase in
approximately 2.5 acres of developed area. The CT 01-09 rational method hydrology was used
to prepare a confluence analysis and determine the updated, larger regional peak flowrate.
The net effect of the increase in Parcel 3 drainage area on the CT 01-09 hydrology is an increase
in the regional (undetained) 100-year peak flowrate from 110.7 cfs to 120.1 cfs. The revised
regional undetained peak flow hydrograph was analyzed using SWMM detention basin routing
to determine if the existing basin and outflow structure has sufficient capacity to detain the
increased peak flow rate. The results are summarized in the table below:
Hydrologic Comparison at Existing Basin Outflow Area
(ac)
Runoff
Coefficient
Q100
(cfs)
CT 01-09 Existing Condition 35.5 0.35 55
CT 2017-0003 Proposed Condition (Undetained) 37 0.63 120.1
CT 2017-0003 Proposed Condition (Detained) 49
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The re-routing of the comparably marginal increase in undetained regional peak flow produces
results that remain substantially similar to the conclusions reached in the original CT 01-09
drainage report. Therefore, it is demonstrated that the existing detention basin has sufficient
hydraulic capacity to mitigate the Parcel 3 100-year peak flow rate and no modifications to the
existing basin or the control structure are necessary. We conclude that the net effect of the Parcel
3 hydrologic increase to the basin will not produce an adverse effect on existing downstream
peak flow capacity.
Detention modeling for the proposed Parcel 3 and the La Costa Square development
demonstrates that the proposed discharge does not exceed the original design for the West
detention basin. See Exhibit “C” for revised detention analysis.
The proposed condition will significantly reduce the area tributary to easterly La Costa curb inlet
and storm drain system. The tributary area was reduced by shifting the easterly temporary
sediment basin area to the west detention basin. Since the project biofiltration basin (Basin #2)
will provide HMP mitigation for the driveway entry and slopes, no further detention calculations
or downstream analysis should be necessary.
7. Hydraulics
As described in Section 5, the primary storm drain system (Line A) is located within the main
east-west driveway and represents the detention storage volume with a 36” diameter storm drain
located east of the main driveway entry, and parallel 36” and 30” pipes located west of the
driveway. The easterly pipe and the westerly pipes are connected to a common cleanout
(Diversion Structure) at the center of the site.
Outflows from the system are regulated by both MWS#1 (lower flow path) and the Flow Control
Structure (upper flow path). The MWS unit does not have an internal bypass. All of the lateral
storm drain lines are connected to the lower pipe in order to ensure that required runoff flows
through MWS#1 before larger flows can reach the upper leg.
The hydrology & hydraulics calculations (CivilD) located in Exhibit “A,” provide peak flow
estimates from the subareas along the length of the backbone storm drain system. Calculations
begin at the upper/east end of the site, accumulating flows along the system length to the existing
detention basin at the west end of the site. These calculations provide an estimated time of
concentration for the backbone system with corresponding flows from the subareas. However,
normal flow routing is interrupted when the backbone storm drain system is used as the detention
storage with outflow restricted by the control structures. The calculations are used up to the
control structures to provide peak flow estimates.
Outflows at the two control locations are governed by the detention model, which determines the
flow rate at each control point. The storage depth results in a submerged back water condition
along the entire length of the storm drain. Flows within the westerly parallel pipes are
controlled by the respective control structure. Flow rates within the easterly portion are based
upon the combined flows, reduced by the lateral inflows that occur upstream of the diversion
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structure. For submerged conditions, pipe velocities are calculated by dividing the flow rate by
the cross sectional area of the pipe segment. The submerged condition is also true for the
upstream lateral connections.
The storm drains downstream of the control structures remain independent. Runoff from the
downstream subareas are estimated using the subarea flows from CivilD calculations added
directly to the control structure outflows. These adjusted flows are then used to determine the
flow velocities (assuming open channel flow) for the pipe segments between the control structure
and the westerly detention basin. The storm drain hydraulics are summarized as follows;
Backbone System
(Sheet 6 & 7)
Pipe Dia
(in)
Q100
(cfs)
V100
(cfs)
HGL
Node # Comment
CivilD Onsite 1
13+67.40 to 17+40 36 4.29 0.61 288.31 100-103,
200-103
CivilD Flow Rate
13+02.45 to 13+67.40 36 7.13 1.01 288.31 103-104 CivilD Flow Rate
Lateral N - Line E 12 6.40 8.15 288.31 N/A CivilD Flow Rate
Lateral S - Line E 12 0.71 0.90 288.31 N/A CivilD Flow Rate
Diversion Structure 17.3 288.31 103-104 Combined Outflow
Upper Pipe to Control
Structure
30 16.4 3.34 288.31 104-606 HMP-1 Outflow
Lower to MWS#1 36 0.9 0.13 288.31 104-106 MWS#1 Outflow
Control Structure
Outflow - Sheet 6
Pipe Dia
(in)
Q100
(cfs)
V100
(cfs)
Depth
(ft)
Node # Comment
CivilD Onsite 3
9+80.03 to 10+57 18 16.4 14.58 0.91 606-604 Normal Depth
Add Rear Slope 18 2.2 13.24 0.23 600-604 CivilD Flow Rate
Exist 18” SD 18 18.6 22.30 0.72 604-605 Normal Depth
Exist Headwall 18 18.6 10.53 >1.0 604-605 Full Flow
MWS#1 Outflow
Sheet 5, 11
Pipe Dia
(in)
Q100
(cfs)
V100
(cfs)
Depth
(ft)
Node # Comment
CivilD Onsite 2
10+92.17 to MWS#1 12 0.9 8.05 0.20 MWS-
106
Normal Depth
10+31.40 to 10+92.17 12 0.9 9.07 0.18 106-107 Normal Depth
Add MWS#2 Flows 18 1.2 20.33 0.11 502-107 CivilD Flow Rate
10+00 to 10+31.40 18 2.1 5.94 0.38 107-108 Normal Depth
New Headwall
See Exhibit “A” for the Summary of Hydraulic Calculations and the CivilD calculations.
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8. Inlet Sizing
Curb inlets are Regional Standard Drawings Type B inlets with a 4” local curb depression (10”
curb face) with a 2% cross fall. Curb length is defined as 1’ greater than the opening length.
Sump Condition: Opening length determined based upon orifice flow using maximum ponding
depth and opening height, typically 1.7 cfs per foot.
Passing Grade Condition: Opening length determined by the upstream flow depth, local
depression (4”).
Openings in sump conditions exceed the minimum an interception capacity of two cfs per lineal
foot of opening per Carlsbad City Standards chapter 5.4.A (excerpts included in the Appendix).
The proposed inlets shall have an opening width of at least 4 feet for maintenance purposes.
See Exhibit “B” for Inlet Calculations.
9. Conclusion
The above calculation demonstrate that the existing detention basin has sufficient hydraulic
capacity to mitigate the Parcel 3 100-year peak flow rate and no modifications to the existing
basin or the control structure are necessary. We conclude that the net effect of the Parcel 3
hydrologic increase to the basin will not produce an adverse effect on existing downstream peak
flow capacity.
The proposed condition will reduce the area tributary to the easterly La Costa curb inlet and
storm drain system. The tributary area was reduced by shifting area the west detention basin.
Since the project biofiltration basin (Basin #2) will provide HMP mitigation for the driveway
entry and slopes, no further detention calculations or downstream analysis was warranted.
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EXHIBIT A
Proposed Hydrology
Hydraulic Summary
La Costa Town Square Final 11/8/2022
P6=2.9
Type D Soil
Current Condition Basin Area % Imperv C C x A Tc I100 Q100
E-1 East Pad 0.10 0 0.35 0.035 8.0 5.643 0.20
E-2 Eas Sediment 2.11 0 0.35 0.739 8.0 5.643 4.17
2.21 0.774 8.0 5.643 4.36
E-5 Middle 0.08 0 0.35 0.028 8.0 5.643 0.16
E-6 Driveway 0.91 0 0.35 0.319 8.0 5.643 1.80
0.99 0.347 8.0 5.643 1.96
East Subtotal 3.20 6.32
E-3 Rear Slope 0.07 0 0.35 0.025 8.0 5.643 0.14
E-4 Rear Slope 0.78 0 0.35 0.273 8.0 5.643 1.54
E-7 West Pad 0.09 0 0.35 0.032 8.0 5.643 0.18
E-8 West Sediment 1.53 0 0.35 0.536 8.0 5.643 3.02
West Subotal 2.47 0.865 8.0 5.643 4.88
Total 5.67 0 0.35 1.985 8.0 5.643 11.20
D:\76882 La Costa Town Square\13 Reports\ProjectData.xlsx Tab: Hydrology
San Diego County Rational Hydrology Program
CIVILCADD/CIVILDESIGN Engineering Software,(c)1991-2014 Version 9.0
Rational method hydrology program based on
San Diego County Flood Control Division 2003 hydrology manual
Rational Hydrology Study Date: 11/28/22
------------------------------------------------------------------------
LA COSTA
ONSITE
1
------------------------------------------------------------------------
********* Hydrology Study Control Information **********
------------------------------------------------------------------------
Program License Serial Number 6334
------------------------------------------------------------------------
Rational hydrology study storm event year is 100.0
English (in-lb) input data Units used
Map data precipitation entered:
6 hour, precipitation(inches) = 2.900
24 hour precipitation(inches) = 5.100
P6/P24 = 56.9%
San Diego hydrology manual 'C' values used
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 100.000 to Point/Station 101.000
**** INITIAL AREA EVALUATION ****
______________________________________________________________________
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[HIGH DENSITY RESIDENTIAL ]
(24.0 DU/A or Less )
Impervious value, Ai = 0.650
Sub-Area C Value = 0.710
Initial subarea total flow distance = 56.000(Ft.)
Highest elevation = 320.000(Ft.)
Lowest elevation = 296.400(Ft.)
Elevation difference = 23.600(Ft.) Slope = 42.143 %
INITIAL AREA TIME OF CONCENTRATION CALCULATIONS:
The maximum overland flow distance is 100.00 (Ft)
for the top area slope value of 42.14 %, in a development type of
24.0 DU/A or Less
In Accordance With Figure 3-3
Initial Area Time of Concentration = 2.02 minutes
TC = [1.8*(1.1-C)*distance(Ft.)^.5)/(% slope^(1/3)]
TC = [1.8*(1.1-0.7100)*( 100.000^.5)/( 42.143^(1/3)]= 2.02
Calculated TC of 2.017 minutes is less than 5 minutes,
resetting TC to 5.0 minutes for rainfall intensity calculations
Rainfall intensity (I) = 7.641(In/Hr) for a 100.0 year storm
1
Effective runoff coefficient used for area (Q=KCIA) is C = 0.710
Subarea runoff = 0.179(CFS)
Total initial stream area = 0.033(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 101.000 to Point/Station 102.000
**** STREET FLOW TRAVEL TIME + SUBAREA FLOW ADDITION ****
______________________________________________________________________
Top of street segment elevation = 296.400(Ft.)
End of street segment elevation = 290.000(Ft.)
Length of street segment = 516.300(Ft.)
Height of curb above gutter flowline = 6.0(In.)
Width of half street (curb to crown) = 13.000(Ft.)
Distance from crown to crossfall grade break = 1.500(Ft.)
Slope from gutter to grade break (v/hz) = 0.020
Slope from grade break to crown (v/hz) = 0.020
Street flow is on [1] side(s) of the street
Distance from curb to property line = 10.000(Ft.)
Slope from curb to property line (v/hz) = 0.020
Gutter width = 1.500(Ft.)
Gutter hike from flowline = 1.540(In.)
Manning's N in gutter = 0.0150
Manning's N from gutter to grade break = 0.0150
Manning's N from grade break to crown = 0.0150
Estimated mean flow rate at midpoint of street = 0.978(CFS)
Depth of flow = 0.229(Ft.), Average velocity = 1.946(Ft/s)
Streetflow hydraulics at midpoint of street travel:
Halfstreet flow width = 6.549(Ft.)
Flow velocity = 1.95(Ft/s)
Travel time = 4.42 min. TC = 6.44 min.
Adding area flow to street
Rainfall intensity (I) = 6.490(In/Hr) for a 100.0 year storm
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[HIGH DENSITY RESIDENTIAL ]
(24.0 DU/A or Less )
Impervious value, Ai = 0.650
Sub-Area C Value = 0.710
Rainfall intensity = 6.490(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.710 CA = 0.285
Subarea runoff = 1.673(CFS) for 0.369(Ac.)
Total runoff = 1.852(CFS) Total area = 0.402(Ac.)
Street flow at end of street = 1.852(CFS)
Half street flow at end of street = 1.852(CFS)
Depth of flow = 0.271(Ft.), Average velocity = 2.250(Ft/s)
Flow width (from curb towards crown)= 8.658(Ft.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 101.000 to Point/Station 102.000
**** SUBAREA FLOW ADDITION ****
______________________________________________________________________
Rainfall intensity (I) = 6.490(In/Hr) for a 100.0 year storm
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
2
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[HIGH DENSITY RESIDENTIAL ]
(24.0 DU/A or Less )
Impervious value, Ai = 0.650
Sub-Area C Value = 0.710
Time of concentration = 6.44 min.
Rainfall intensity = 6.490(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.710 CA = 0.386
Subarea runoff = 0.650(CFS) for 0.141(Ac.)
Total runoff = 2.502(CFS) Total area = 0.543(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 101.000 to Point/Station 102.000
**** SUBAREA FLOW ADDITION ****
______________________________________________________________________
Rainfall intensity (I) = 6.490(In/Hr) for a 100.0 year storm
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[HIGH DENSITY RESIDENTIAL ]
(24.0 DU/A or Less )
Impervious value, Ai = 0.650
Sub-Area C Value = 0.710
Time of concentration = 6.44 min.
Rainfall intensity = 6.490(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.710 CA = 0.444
Subarea runoff = 0.378(CFS) for 0.082(Ac.)
Total runoff = 2.880(CFS) Total area = 0.625(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 102.000 to Point/Station 103.000
**** PIPEFLOW TRAVEL TIME (User specified size) ****
______________________________________________________________________
Upstream point/station elevation = 285.800(Ft.)
Downstream point/station elevation = 282.600(Ft.)
Pipe length = 11.20(Ft.) Slope = 0.2857 Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 2.880(CFS)
Given pipe size = 12.00(In.)
Calculated individual pipe flow = 2.880(CFS)
Normal flow depth in pipe = 3.15(In.)
Flow top width inside pipe = 10.56(In.)
Critical Depth = 8.73(In.)
Pipe flow velocity = 17.48(Ft/s)
Travel time through pipe = 0.01 min.
Time of concentration (TC) = 6.45 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 102.000 to Point/Station 103.000
**** CONFLUENCE OF MAIN STREAMS ****
______________________________________________________________________
The following data inside Main Stream is listed:
In Main Stream number: 1
3
Stream flow area = 0.625(Ac.)
Runoff from this stream = 2.880(CFS)
Time of concentration = 6.45 min.
Rainfall intensity = 6.483(In/Hr)
Program is now starting with Main Stream No. 2
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 200.000 to Point/Station 201.000
**** INITIAL AREA EVALUATION ****
______________________________________________________________________
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[HIGH DENSITY RESIDENTIAL ]
(24.0 DU/A or Less )
Impervious value, Ai = 0.650
Sub-Area C Value = 0.710
Initial subarea total flow distance = 45.000(Ft.)
Highest elevation = 295.400(Ft.)
Lowest elevation = 294.700(Ft.)
Elevation difference = 0.700(Ft.) Slope = 1.556 %
Top of Initial Area Slope adjusted by User to 1.600 %
INITIAL AREA TIME OF CONCENTRATION CALCULATIONS:
The maximum overland flow distance is 75.00 (Ft)
for the top area slope value of 1.60 %, in a development type of
24.0 DU/A or Less
In Accordance With Figure 3-3
Initial Area Time of Concentration = 5.20 minutes
TC = [1.8*(1.1-C)*distance(Ft.)^.5)/(% slope^(1/3)]
TC = [1.8*(1.1-0.7100)*( 75.000^.5)/( 1.600^(1/3)]= 5.20
Rainfall intensity (I) = 7.452(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for area (Q=KCIA) is C = 0.710
Subarea runoff = 0.079(CFS)
Total initial stream area = 0.015(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 201.000 to Point/Station 202.000
**** PIPEFLOW TRAVEL TIME (User specified size) ****
______________________________________________________________________
Upstream point/station elevation = 286.600(Ft.)
Downstream point/station elevation = 286.200(Ft.)
Pipe length = 15.50(Ft.) Slope = 0.0258 Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 0.079(CFS)
Given pipe size = 8.00(In.)
Calculated individual pipe flow = 0.079(CFS)
Normal flow depth in pipe = 1.11(In.)
Flow top width inside pipe = 5.52(In.)
Critical Depth = 1.53(In.)
Pipe flow velocity = 2.73(Ft/s)
Travel time through pipe = 0.09 min.
Time of concentration (TC) = 5.29 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 202.000 to Point/Station 103.000
**** SUBAREA FLOW ADDITION ****
4
______________________________________________________________________
Rainfall intensity (I) = 7.366(In/Hr) for a 100.0 year storm
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[HIGH DENSITY RESIDENTIAL ]
(24.0 DU/A or Less )
Impervious value, Ai = 0.650
Sub-Area C Value = 0.710
Time of concentration = 5.29 min.
Rainfall intensity = 7.366(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.710 CA = 0.164
Subarea runoff = 1.129(CFS) for 0.216(Ac.)
Total runoff = 1.208(CFS) Total area = 0.231(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 202.000 to Point/Station 103.000
**** SUBAREA FLOW ADDITION ****
______________________________________________________________________
Rainfall intensity (I) = 7.366(In/Hr) for a 100.0 year storm
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[HIGH DENSITY RESIDENTIAL ]
(24.0 DU/A or Less )
Impervious value, Ai = 0.650
Sub-Area C Value = 0.710
Time of concentration = 5.29 min.
Rainfall intensity = 7.366(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.710 CA = 0.254
Subarea runoff = 0.664(CFS) for 0.127(Ac.)
Total runoff = 1.872(CFS) Total area = 0.358(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 202.000 to Point/Station 103.000
**** SUBAREA FLOW ADDITION ****
______________________________________________________________________
Rainfall intensity (I) = 7.366(In/Hr) for a 100.0 year storm
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[HIGH DENSITY RESIDENTIAL ]
(24.0 DU/A or Less )
Impervious value, Ai = 0.650
Sub-Area C Value = 0.710
Time of concentration = 5.29 min.
Rainfall intensity = 7.366(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.710 CA = 0.484
Subarea runoff = 1.694(CFS) for 0.324(Ac.)
Total runoff = 3.567(CFS) Total area = 0.682(Ac.)
5
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 202.000 to Point/Station 103.000
**** SUBAREA FLOW ADDITION ****
______________________________________________________________________
Rainfall intensity (I) = 7.366(In/Hr) for a 100.0 year storm
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[HIGH DENSITY RESIDENTIAL ]
(24.0 DU/A or Less )
Impervious value, Ai = 0.650
Sub-Area C Value = 0.710
Time of concentration = 5.29 min.
Rainfall intensity = 7.366(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.710 CA = 0.582
Subarea runoff = 0.722(CFS) for 0.138(Ac.)
Total runoff = 4.288(CFS) Total area = 0.820(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 202.000 to Point/Station 103.000
**** PIPEFLOW TRAVEL TIME (User specified size) ****
______________________________________________________________________
Upstream point/station elevation = 285.800(Ft.)
Downstream point/station elevation = 283.200(Ft.)
Pipe length = 368.10(Ft.) Slope = 0.0071 Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 4.288(CFS)
Given pipe size = 36.00(In.)
Calculated individual pipe flow = 4.288(CFS)
Normal flow depth in pipe = 6.74(In.)
Flow top width inside pipe = 28.08(In.)
Critical depth could not be calculated.
Pipe flow velocity = 4.69(Ft/s)
Travel time through pipe = 1.31 min.
Time of concentration (TC) = 6.60 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 202.000 to Point/Station 103.000
**** CONFLUENCE OF MAIN STREAMS ****
______________________________________________________________________
The following data inside Main Stream is listed:
In Main Stream number: 2
Stream flow area = 0.820(Ac.)
Runoff from this stream = 4.288(CFS)
Time of concentration = 6.60 min.
Rainfall intensity = 6.387(In/Hr)
Summary of stream data:
Stream Flow rate TC Rainfall Intensity
No. (CFS) (min) (In/Hr)
1 2.880 6.45 6.483
2 4.288 6.60 6.387
Qmax(1) =
6
1.000 * 1.000 * 2.880) +
1.000 * 0.977 * 4.288) + = 7.071
Qmax(2) =
0.985 * 1.000 * 2.880) +
1.000 * 1.000 * 4.288) + = 7.126
Total of 2 main streams to confluence:
Flow rates before confluence point:
2.880 4.288
Maximum flow rates at confluence using above data:
7.071 7.126
Area of streams before confluence:
0.625 0.820
Results of confluence:
Total flow rate = 7.126(CFS)
Time of concentration = 6.601 min.
Effective stream area after confluence = 1.445(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 103.000 to Point/Station 104.000
**** SUBAREA FLOW ADDITION ****
______________________________________________________________________
Rainfall intensity (I) = 6.387(In/Hr) for a 100.0 year storm
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[HIGH DENSITY RESIDENTIAL ]
(24.0 DU/A or Less )
Impervious value, Ai = 0.650
Sub-Area C Value = 0.710
Time of concentration = 6.60 min.
Rainfall intensity = 6.387(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.710 CA = 1.384
Subarea runoff = 1.718(CFS) for 0.505(Ac.)
Total runoff = 8.843(CFS) Total area = 1.950(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 103.000 to Point/Station 104.000
**** SUBAREA FLOW ADDITION ****
______________________________________________________________________
Rainfall intensity (I) = 6.387(In/Hr) for a 100.0 year storm
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[HIGH DENSITY RESIDENTIAL ]
(24.0 DU/A or Less )
Impervious value, Ai = 0.650
Sub-Area C Value = 0.710
Time of concentration = 6.60 min.
Rainfall intensity = 6.387(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.710 CA = 2.016
7
Subarea runoff = 4.032(CFS) for 0.889(Ac.)
Total runoff = 12.875(CFS) Total area = 2.839(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 103.000 to Point/Station 104.000
**** SUBAREA FLOW ADDITION ****
______________________________________________________________________
Rainfall intensity (I) = 6.387(In/Hr) for a 100.0 year storm
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[HIGH DENSITY RESIDENTIAL ]
(24.0 DU/A or Less )
Impervious value, Ai = 0.650
Sub-Area C Value = 0.710
Time of concentration = 6.60 min.
Rainfall intensity = 6.387(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.710 CA = 2.121
Subarea runoff = 0.671(CFS) for 0.148(Ac.)
Total runoff = 13.546(CFS) Total area = 2.987(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 103.000 to Point/Station 104.000
**** SUBAREA FLOW ADDITION ****
______________________________________________________________________
Rainfall intensity (I) = 6.387(In/Hr) for a 100.0 year storm
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[HIGH DENSITY RESIDENTIAL ]
(24.0 DU/A or Less )
Impervious value, Ai = 0.650
Sub-Area C Value = 0.710
Time of concentration = 6.60 min.
Rainfall intensity = 6.387(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.710 CA = 2.232
Subarea runoff = 0.712(CFS) for 0.157(Ac.)
Total runoff = 14.258(CFS) Total area = 3.144(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 103.000 to Point/Station 104.000
**** PIPEFLOW TRAVEL TIME (User specified size) ****
______________________________________________________________________
Upstream point/station elevation = 282.900(Ft.)
Downstream point/station elevation = 281.600(Ft.)
Pipe length = 60.80(Ft.) Slope = 0.0214 Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 14.258(CFS)
Given pipe size = 36.00(In.)
Calculated individual pipe flow = 14.258(CFS)
Normal flow depth in pipe = 9.30(In.)
Flow top width inside pipe = 31.52(In.)
Critical Depth = 14.43(In.)
8
Pipe flow velocity = 9.85(Ft/s)
Travel time through pipe = 0.10 min.
Time of concentration (TC) = 6.70 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 104.000 to Point/Station 105.000
**** SUBAREA FLOW ADDITION ****
______________________________________________________________________
Rainfall intensity (I) = 6.324(In/Hr) for a 100.0 year storm
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[HIGH DENSITY RESIDENTIAL ]
(24.0 DU/A or Less )
Impervious value, Ai = 0.650
Sub-Area C Value = 0.710
Time of concentration = 6.70 min.
Rainfall intensity = 6.324(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.710 CA = 2.305
Subarea runoff = 0.321(CFS) for 0.103(Ac.)
Total runoff = 14.579(CFS) Total area = 3.247(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 104.000 to Point/Station 105.000
**** SUBAREA FLOW ADDITION ****
______________________________________________________________________
Rainfall intensity (I) = 6.324(In/Hr) for a 100.0 year storm
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[HIGH DENSITY RESIDENTIAL ]
(24.0 DU/A or Less )
Impervious value, Ai = 0.650
Sub-Area C Value = 0.710
Time of concentration = 6.70 min.
Rainfall intensity = 6.324(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.710 CA = 2.378
Subarea runoff = 0.462(CFS) for 0.103(Ac.)
Total runoff = 15.042(CFS) Total area = 3.350(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 104.000 to Point/Station 105.000
**** SUBAREA FLOW ADDITION ****
______________________________________________________________________
Rainfall intensity (I) = 6.324(In/Hr) for a 100.0 year storm
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[HIGH DENSITY RESIDENTIAL ]
(24.0 DU/A or Less )
Impervious value, Ai = 0.650
9
Sub-Area C Value = 0.710
Time of concentration = 6.70 min.
Rainfall intensity = 6.324(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.710 CA = 2.461
Subarea runoff = 0.521(CFS) for 0.116(Ac.)
Total runoff = 15.563(CFS) Total area = 3.466(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 104.000 to Point/Station 105.000
**** SUBAREA FLOW ADDITION ****
______________________________________________________________________
Rainfall intensity (I) = 6.324(In/Hr) for a 100.0 year storm
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[HIGH DENSITY RESIDENTIAL ]
(24.0 DU/A or Less )
Impervious value, Ai = 0.650
Sub-Area C Value = 0.710
Time of concentration = 6.70 min.
Rainfall intensity = 6.324(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.710 CA = 2.535
Subarea runoff = 0.467(CFS) for 0.104(Ac.)
Total runoff = 16.029(CFS) Total area = 3.570(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 104.000 to Point/Station 105.000
**** PIPEFLOW TRAVEL TIME (User specified size) ****
______________________________________________________________________
Upstream point/station elevation = 280.100(Ft.)
Downstream point/station elevation = 277.200(Ft.)
Pipe length = 320.00(Ft.) Slope = 0.0091 Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 16.029(CFS)
Given pipe size = 36.00(In.)
Calculated individual pipe flow = 16.029(CFS)
Normal flow depth in pipe = 12.33(In.)
Flow top width inside pipe = 34.17(In.)
Critical Depth = 15.33(In.)
Pipe flow velocity = 7.49(Ft/s)
Travel time through pipe = 0.71 min.
Time of concentration (TC) = 7.42 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 104.000 to Point/Station 105.000
**** CONFLUENCE OF MAIN STREAMS ****
______________________________________________________________________
The following data inside Main Stream is listed:
In Main Stream number: 1
Stream flow area = 3.570(Ac.)
Runoff from this stream = 16.029(CFS)
Time of concentration = 7.42 min.
Rainfall intensity = 5.925(In/Hr)
Program is now starting with Main Stream No. 2
10
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 300.000 to Point/Station 301.000
**** INITIAL AREA EVALUATION ****
______________________________________________________________________
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[HIGH DENSITY RESIDENTIAL ]
(24.0 DU/A or Less )
Impervious value, Ai = 0.650
Sub-Area C Value = 0.710
Initial subarea total flow distance = 41.000(Ft.)
Highest elevation = 290.600(Ft.)
Lowest elevation = 290.200(Ft.)
Elevation difference = 0.400(Ft.) Slope = 0.976 %
Top of Initial Area Slope adjusted by User to 1.000 %
INITIAL AREA TIME OF CONCENTRATION CALCULATIONS:
The maximum overland flow distance is 65.00 (Ft)
for the top area slope value of 1.00 %, in a development type of
24.0 DU/A or Less
In Accordance With Figure 3-3
Initial Area Time of Concentration = 5.66 minutes
TC = [1.8*(1.1-C)*distance(Ft.)^.5)/(% slope^(1/3)]
TC = [1.8*(1.1-0.7100)*( 65.000^.5)/( 1.000^(1/3)]= 5.66
Rainfall intensity (I) = 7.054(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for area (Q=KCIA) is C = 0.710
Subarea runoff = 0.070(CFS)
Total initial stream area = 0.014(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 301.000 to Point/Station 302.000
**** SUBAREA FLOW ADDITION ****
______________________________________________________________________
Rainfall intensity (I) = 7.054(In/Hr) for a 100.0 year storm
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[HIGH DENSITY RESIDENTIAL ]
(24.0 DU/A or Less )
Impervious value, Ai = 0.650
Sub-Area C Value = 0.710
Time of concentration = 5.66 min.
Rainfall intensity = 7.054(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.710 CA = 0.119
Subarea runoff = 0.771(CFS) for 0.154(Ac.)
Total runoff = 0.841(CFS) Total area = 0.168(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 302.000 to Point/Station 303.000
**** PIPEFLOW TRAVEL TIME (User specified size) ****
______________________________________________________________________
Upstream point/station elevation = 284.000(Ft.)
11
Downstream point/station elevation = 282.900(Ft.)
Pipe length = 56.50(Ft.) Slope = 0.0195 Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 0.841(CFS)
Given pipe size = 12.00(In.)
Calculated individual pipe flow = 0.841(CFS)
Normal flow depth in pipe = 3.34(In.)
Flow top width inside pipe = 10.76(In.)
Critical Depth = 4.60(In.)
Pipe flow velocity = 4.71(Ft/s)
Travel time through pipe = 0.20 min.
Time of concentration (TC) = 5.86 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 303.000 to Point/Station 304.000
**** SUBAREA FLOW ADDITION ****
______________________________________________________________________
Rainfall intensity (I) = 6.898(In/Hr) for a 100.0 year storm
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[HIGH DENSITY RESIDENTIAL ]
(24.0 DU/A or Less )
Impervious value, Ai = 0.650
Sub-Area C Value = 0.710
Time of concentration = 5.86 min.
Rainfall intensity = 6.898(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.710 CA = 0.216
Subarea runoff = 0.647(CFS) for 0.136(Ac.)
Total runoff = 1.489(CFS) Total area = 0.304(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 303.000 to Point/Station 304.000
**** PIPEFLOW TRAVEL TIME (User specified size) ****
______________________________________________________________________
Upstream point/station elevation = 282.400(Ft.)
Downstream point/station elevation = 280.400(Ft.)
Pipe length = 48.60(Ft.) Slope = 0.0412 Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 1.489(CFS)
Given pipe size = 12.00(In.)
Calculated individual pipe flow = 1.489(CFS)
Normal flow depth in pipe = 3.70(In.)
Flow top width inside pipe = 11.08(In.)
Critical Depth = 6.21(In.)
Pipe flow velocity = 7.25(Ft/s)
Travel time through pipe = 0.11 min.
Time of concentration (TC) = 5.97 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 304.000 to Point/Station 105.000
**** PIPEFLOW TRAVEL TIME (User specified size) ****
______________________________________________________________________
Upstream point/station elevation = 280.000(Ft.)
Downstream point/station elevation = 278.100(Ft.)
Pipe length = 130.60(Ft.) Slope = 0.0145 Manning's N = 0.013
12
No. of pipes = 1 Required pipe flow = 1.489(CFS)
Given pipe size = 18.00(In.)
Calculated individual pipe flow = 1.489(CFS)
Normal flow depth in pipe = 4.17(In.)
Flow top width inside pipe = 15.18(In.)
Critical Depth = 5.48(In.)
Pipe flow velocity = 4.81(Ft/s)
Travel time through pipe = 0.45 min.
Time of concentration (TC) = 6.42 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 304.000 to Point/Station 105.000
**** CONFLUENCE OF MAIN STREAMS ****
______________________________________________________________________
The following data inside Main Stream is listed:
In Main Stream number: 2
Stream flow area = 0.304(Ac.)
Runoff from this stream = 1.489(CFS)
Time of concentration = 6.42 min.
Rainfall intensity = 6.500(In/Hr)
Summary of stream data:
Stream Flow rate TC Rainfall Intensity
No. (CFS) (min) (In/Hr)
1 16.029 7.42 5.925
2 1.489 6.42 6.500
Qmax(1) =
1.000 * 1.000 * 16.029) +
0.912 * 1.000 * 1.489) + = 17.387
Qmax(2) =
1.000 * 0.866 * 16.029) +
1.000 * 1.000 * 1.489) + = 15.374
Total of 2 main streams to confluence:
Flow rates before confluence point:
16.029 1.489
Maximum flow rates at confluence using above data:
17.387 15.374
Area of streams before confluence:
3.570 0.304
Results of confluence:
Total flow rate = 17.387(CFS)
Time of concentration = 7.416 min.
Effective stream area after confluence = 3.874(Ac.)
End of computations, total study area = 3.874 (Ac.)
13
San Diego County Rational Hydrology Program
CIVILCADD/CIVILDESIGN Engineering Software,(c)1991-2014 Version 9.0
Rational method hydrology program based on
San Diego County Flood Control Division 2003 hydrology manual
Rational Hydrology Study Date: 11/17/22
------------------------------------------------------------------------
LA COSTA
ONSITE
2
------------------------------------------------------------------------
********* Hydrology Study Control Information **********
------------------------------------------------------------------------
Program License Serial Number 6334
------------------------------------------------------------------------
Rational hydrology study storm event year is 100.0
English (in-lb) input data Units used
Map data precipitation entered:
6 hour, precipitation(inches) = 2.900
24 hour precipitation(inches) = 5.100
P6/P24 = 56.9%
San Diego hydrology manual 'C' values used
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 106.000 to Point/Station 107.000
**** USER DEFINED FLOW INFORMATION AT A POINT ****
______________________________________________________________________
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[HIGH DENSITY RESIDENTIAL ]
(24.0 DU/A or Less )
Impervious value, Ai = 0.650
Sub-Area C Value = 0.710
Rainfall intensity (I) = 7.641(In/Hr) for a 100.0 year storm
User specified values are as follows:
TC = 5.00 min. Rain intensity = 7.64(In/Hr)
Total area = 0.000(Ac.) Total runoff = 0.900(CFS)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 106.000 to Point/Station 107.000
**** CONFLUENCE OF MAIN STREAMS ****
______________________________________________________________________
The following data inside Main Stream is listed:
In Main Stream number: 1
Stream flow area = 0.000(Ac.)
Runoff from this stream = 0.900(CFS)
Time of concentration = 5.00 min.
1
Downstream of
MWS#1 to
MWS#2
Rainfall intensity = 7.641(In/Hr)
Program is now starting with Main Stream No. 2
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 500.000 to Point/Station 501.000
**** INITIAL AREA EVALUATION ****
______________________________________________________________________
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[HIGH DENSITY RESIDENTIAL ]
(24.0 DU/A or Less )
Impervious value, Ai = 0.650
Sub-Area C Value = 0.710
Initial subarea total flow distance = 47.000(Ft.)
Highest elevation = 293.700(Ft.)
Lowest elevation = 293.400(Ft.)
Elevation difference = 0.300(Ft.) Slope = 0.638 %
Top of Initial Area Slope adjusted by User to 0.660 %
INITIAL AREA TIME OF CONCENTRATION CALCULATIONS:
The maximum overland flow distance is 50.00 (Ft)
for the top area slope value of 0.66 %, in a development type of
24.0 DU/A or Less
In Accordance With Figure 3-3
Initial Area Time of Concentration = 5.70 minutes
TC = [1.8*(1.1-C)*distance(Ft.)^.5)/(% slope^(1/3)]
TC = [1.8*(1.1-0.7100)*( 50.000^.5)/( 0.660^(1/3)]= 5.70
Rainfall intensity (I) = 7.020(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for area (Q=KCIA) is C = 0.710
Subarea runoff = 0.125(CFS)
Total initial stream area = 0.025(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 501.000 to Point/Station 502.000
**** STREET FLOW TRAVEL TIME + SUBAREA FLOW ADDITION ****
______________________________________________________________________
Top of street segment elevation = 293.400(Ft.)
End of street segment elevation = 277.500(Ft.)
Length of street segment = 215.000(Ft.)
Height of curb above gutter flowline = 6.0(In.)
Width of half street (curb to crown) = 16.000(Ft.)
Distance from crown to crossfall grade break = 14.500(Ft.)
Slope from gutter to grade break (v/hz) = 0.080
Slope from grade break to crown (v/hz) = 0.020
Street flow is on [1] side(s) of the street
Distance from curb to property line = 5.000(Ft.)
Slope from curb to property line (v/hz) = 0.020
Gutter width = 1.500(Ft.)
Gutter hike from flowline = 1.500(In.)
Manning's N in gutter = 0.0150
Manning's N from gutter to grade break = 0.0150
Manning's N from grade break to crown = 0.0150
Estimated mean flow rate at midpoint of street = 0.626(CFS)
Depth of flow = 0.157(Ft.), Average velocity = 3.721(Ft/s)
Streetflow hydraulics at midpoint of street travel:
Halfstreet flow width = 3.115(Ft.)
2
Flow velocity = 3.72(Ft/s)
Travel time = 0.96 min. TC = 6.66 min.
Adding area flow to street
Rainfall intensity (I) = 6.348(In/Hr) for a 100.0 year storm
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[HIGH DENSITY RESIDENTIAL ]
(24.0 DU/A or Less )
Impervious value, Ai = 0.650
Sub-Area C Value = 0.710
Rainfall intensity = 6.348(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.710 CA = 0.188
Subarea runoff = 1.070(CFS) for 0.240(Ac.)
Total runoff = 1.194(CFS) Total area = 0.265(Ac.)
Street flow at end of street = 1.194(CFS)
Half street flow at end of street = 1.194(CFS)
Depth of flow = 0.189(Ft.), Average velocity = 4.109(Ft/s)
Flow width (from curb towards crown)= 4.684(Ft.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 502.000 to Point/Station 503.000
**** PIPEFLOW TRAVEL TIME (User specified size) ****
______________________________________________________________________
Upstream point/station elevation = 273.600(Ft.)
Downstream point/station elevation = 269.700(Ft.)
Pipe length = 4.00(Ft.) Slope = 0.9750 Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 1.194(CFS)
Given pipe size = 12.00(In.)
Calculated individual pipe flow = 1.194(CFS)
Normal flow depth in pipe = 1.51(In.)
Flow top width inside pipe = 7.97(In.)
Critical Depth = 5.52(In.)
Pipe flow velocity = 20.79(Ft/s)
Travel time through pipe = 0.00 min.
Time of concentration (TC) = 6.67 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 503.000 to Point/Station 107.000
**** CONFLUENCE OF MAIN STREAMS ****
______________________________________________________________________
The following data inside Main Stream is listed:
In Main Stream number: 2
Stream flow area = 0.265(Ac.)
Runoff from this stream = 1.194(CFS)
Time of concentration = 6.67 min.
Rainfall intensity = 6.346(In/Hr)
Summary of stream data:
Stream Flow rate TC Rainfall Intensity
No. (CFS) (min) (In/Hr)
1 0.900 5.00 7.641
2 1.194 6.67 6.346
3
Qmax(1) =
1.000 * 1.000 * 0.900) +
1.000 * 0.750 * 1.194) + = 1.796
Qmax(2) =
0.831 * 1.000 * 0.900) +
1.000 * 1.000 * 1.194) + = 1.942
Total of 2 main streams to confluence:
Flow rates before confluence point:
0.900 1.194
Maximum flow rates at confluence using above data:
1.796 1.942
Area of streams before confluence:
0.000 0.265
Results of confluence:
Total flow rate = 1.942(CFS)
Time of concentration = 6.667 min.
Effective stream area after confluence = 0.265(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 107.000 to Point/Station 108.000
**** PIPEFLOW TRAVEL TIME (User specified size) ****
______________________________________________________________________
Upstream point/station elevation = 268.400(Ft.)
Downstream point/station elevation = 267.800(Ft.)
Pipe length = 29.40(Ft.) Slope = 0.0204 Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 1.942(CFS)
Given pipe size = 18.00(In.)
Calculated individual pipe flow = 1.942(CFS)
Normal flow depth in pipe = 4.37(In.)
Flow top width inside pipe = 15.44(In.)
Critical Depth = 6.30(In.)
Pipe flow velocity = 5.85(Ft/s)
Travel time through pipe = 0.08 min.
Time of concentration (TC) = 6.75 min.
End of computations, total study area = 0.265 (Ac.)
4
San Diego County Rational Hydrology Program
CIVILCADD/CIVILDESIGN Engineering Software,(c)1991-2014 Version 9.0
Rational method hydrology program based on
San Diego County Flood Control Division 2003 hydrology manual
Rational Hydrology Study Date: 11/28/22
------------------------------------------------------------------------
LA COSTA
ONSITE
3
------------------------------------------------------------------------
********* Hydrology Study Control Information **********
------------------------------------------------------------------------
Program License Serial Number 6334
------------------------------------------------------------------------
Rational hydrology study storm event year is 100.0
English (in-lb) input data Units used
Map data precipitation entered:
6 hour, precipitation(inches) = 2.900
24 hour precipitation(inches) = 5.100
P6/P24 = 56.9%
San Diego hydrology manual 'C' values used
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 606.000 to Point/Station 604.000
**** USER DEFINED FLOW INFORMATION AT A POINT ****
______________________________________________________________________
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[HIGH DENSITY RESIDENTIAL ]
(24.0 DU/A or Less )
Impervious value, Ai = 0.650
Sub-Area C Value = 0.710
Rainfall intensity (I) = 5.923(In/Hr) for a 100.0 year storm
User specified values are as follows:
TC = 7.42 min. Rain intensity = 5.92(In/Hr)
Total area = 3.874(Ac.) Total runoff = 16.400(CFS)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 606.000 to Point/Station 604.000
**** CONFLUENCE OF MAIN STREAMS ****
______________________________________________________________________
The following data inside Main Stream is listed:
In Main Stream number: 1
Stream flow area = 3.874(Ac.)
Runoff from this stream = 16.400(CFS)
Time of concentration = 7.42 min.
1
Downstream of
Control structure
Rainfall intensity = 5.923(In/Hr)
Program is now starting with Main Stream No. 2
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 600.000 to Point/Station 601.000
**** INITIAL AREA EVALUATION ****
______________________________________________________________________
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[UNDISTURBED NATURAL TERRAIN ]
(Permanent Open Space )
Impervious value, Ai = 0.000
Sub-Area C Value = 0.350
Initial subarea total flow distance = 35.400(Ft.)
Highest elevation = 335.500(Ft.)
Lowest elevation = 318.800(Ft.)
Elevation difference = 16.700(Ft.) Slope = 47.175 %
Top of Initial Area Slope adjusted by User to 47.000 %
INITIAL AREA TIME OF CONCENTRATION CALCULATIONS:
The maximum overland flow distance is 100.00 (Ft)
for the top area slope value of 47.00 %, in a development type of
Permanent Open Space
In Accordance With Figure 3-3
Initial Area Time of Concentration = 3.74 minutes
TC = [1.8*(1.1-C)*distance(Ft.)^.5)/(% slope^(1/3)]
TC = [1.8*(1.1-0.3500)*( 100.000^.5)/( 47.000^(1/3)]= 3.74
Calculated TC of 3.741 minutes is less than 5 minutes,
resetting TC to 5.0 minutes for rainfall intensity calculations
Rainfall intensity (I) = 7.641(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for area (Q=KCIA) is C = 0.350
Subarea runoff = 0.019(CFS)
Total initial stream area = 0.007(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 601.000 to Point/Station 602.000
**** SUBAREA FLOW ADDITION ****
______________________________________________________________________
Calculated TC of 3.741 minutes is less than 5 minutes,
resetting TC to 5.0 minutes for rainfall intensity calculations
Rainfall intensity (I) = 7.641(In/Hr) for a 100.0 year storm
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[UNDISTURBED NATURAL TERRAIN ]
(Permanent Open Space )
Impervious value, Ai = 0.000
Sub-Area C Value = 0.350
Time of concentration = 3.74 min.
Rainfall intensity = 7.641(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.350 CA = 0.294
Subarea runoff = 2.228(CFS) for 0.833(Ac.)
Total runoff = 2.246(CFS) Total area = 0.840(Ac.)
2
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 601.000 to Point/Station 602.000
**** PIPEFLOW TRAVEL TIME (User specified size) ****
______________________________________________________________________
Upstream point/station elevation = 318.800(Ft.)
Downstream point/station elevation = 306.800(Ft.)
Pipe length = 860.00(Ft.) Slope = 0.0140 Manning's N = 0.015
No. of pipes = 1 Required pipe flow = 2.246(CFS)
Elliptical pipe dimensions: Ratio A/B = 2.000
Height B = 7.50(In.) Width A = 15.00(In.)
Calculated individual pipe flow = 2.246(CFS)
Normal flow depth in pipe = 5.39(In.)
Flow top width inside pipe = 13.49(In.)
Critical Depth = 6.10(In.)
Pipe flow velocity = 4.76(Ft/s)
Travel time through pipe = 3.01 min.
Time of concentration (TC) = 6.75 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 602.000 to Point/Station 603.000
**** PIPEFLOW TRAVEL TIME (User specified size) ****
______________________________________________________________________
Upstream point/station elevation = 294.500(Ft.)
Downstream point/station elevation = 289.700(Ft.)
Pipe length = 28.60(Ft.) Slope = 0.1678 Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 2.246(CFS)
Given pipe size = 12.00(In.)
Calculated individual pipe flow = 2.246(CFS)
Normal flow depth in pipe = 3.18(In.)
Flow top width inside pipe = 10.59(In.)
Critical Depth = 7.70(In.)
Pipe flow velocity = 13.46(Ft/s)
Travel time through pipe = 0.04 min.
Time of concentration (TC) = 6.79 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 603.000 to Point/Station 604.000
**** PIPEFLOW TRAVEL TIME (User specified size) ****
______________________________________________________________________
Upstream point/station elevation = 289.400(Ft.)
Downstream point/station elevation = 277.900(Ft.)
Pipe length = 64.80(Ft.) Slope = 0.1775 Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 2.246(CFS)
Given pipe size = 12.00(In.)
Calculated individual pipe flow = 2.246(CFS)
Normal flow depth in pipe = 3.14(In.)
Flow top width inside pipe = 10.55(In.)
Critical Depth = 7.70(In.)
Pipe flow velocity = 13.74(Ft/s)
Travel time through pipe = 0.08 min.
Time of concentration (TC) = 6.87 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 604.000 to Point/Station 605.000
**** CONFLUENCE OF MAIN STREAMS ****
3
______________________________________________________________________
The following data inside Main Stream is listed:
In Main Stream number: 2
Stream flow area = 0.840(Ac.)
Runoff from this stream = 2.246(CFS)
Time of concentration = 6.87 min.
Rainfall intensity = 6.226(In/Hr)
Summary of stream data:
Stream Flow rate TC Rainfall Intensity
No. (CFS) (min) (In/Hr)
1 16.400 7.42 5.923
2 2.246 6.87 6.226
Qmax(1) =
1.000 * 1.000 * 16.400) +
0.951 * 1.000 * 2.246) + = 18.537
Qmax(2) =
1.000 * 0.926 * 16.400) +
1.000 * 1.000 * 2.246) + = 17.428
Total of 2 main streams to confluence:
Flow rates before confluence point:
16.400 2.246
Maximum flow rates at confluence using above data:
18.537 17.428
Area of streams before confluence:
3.874 0.840
Results of confluence:
Total flow rate = 18.537(CFS)
Time of concentration = 7.420 min.
Effective stream area after confluence = 4.714(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 604.000 to Point/Station 605.000
**** PIPEFLOW TRAVEL TIME (User specified size) ****
______________________________________________________________________
Upstream point/station elevation = 277.600(Ft.)
Downstream point/station elevation = 269.000(Ft.)
Pipe length = 59.00(Ft.) Slope = 0.1458 Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 18.537(CFS)
Given pipe size = 18.00(In.)
Calculated individual pipe flow = 18.537(CFS)
Normal flow depth in pipe = 8.60(In.)
Flow top width inside pipe = 17.98(In.)
Critical depth could not be calculated.
Pipe flow velocity = 22.25(Ft/s)
Travel time through pipe = 0.04 min.
Time of concentration (TC) = 7.46 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 605.000 to Point/Station 108.000
**** PIPEFLOW TRAVEL TIME (User specified size) ****
______________________________________________________________________
4
Upstream point/station elevation = 268.700(Ft.)
Downstream point/station elevation = 268.500(Ft.)
Pipe length = 13.30(Ft.) Slope = 0.0150 Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 18.537(CFS)
Given pipe size = 18.00(In.)
NOTE: Normal flow is pressure flow in user selected pipe size.
The approximate hydraulic grade line above the pipe invert is
2.777(Ft.) at the headworks or inlet of the pipe(s)
Pipe friction loss = 0.414(Ft.)
Minor friction loss = 2.563(Ft.)K-factor = 1.50
Critical depth could not be calculated.
Pipe flow velocity = 10.49(Ft/s)
Travel time through pipe = 0.02 min.
Time of concentration (TC) = 7.49 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 605.000 to Point/Station 108.000
**** CONFLUENCE OF MAIN STREAMS ****
______________________________________________________________________
The following data inside Main Stream is listed:
In Main Stream number: 1
Stream flow area = 4.714(Ac.)
Runoff from this stream = 18.537(CFS)
Time of concentration = 7.49 min.
Rainfall intensity = 5.890(In/Hr)
Program is now starting with Main Stream No. 2
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 107.000 to Point/Station 108.000
**** USER DEFINED FLOW INFORMATION AT A POINT ****
______________________________________________________________________
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[HIGH DENSITY RESIDENTIAL ]
(24.0 DU/A or Less )
Impervious value, Ai = 0.650
Sub-Area C Value = 0.710
Rainfall intensity (I) = 6.296(In/Hr) for a 100.0 year storm
User specified values are as follows:
TC = 6.75 min. Rain intensity = 6.30(In/Hr)
Total area = 0.265(Ac.) Total runoff = 1.940(CFS)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 605.000 to Point/Station 108.000
**** CONFLUENCE OF MAIN STREAMS ****
______________________________________________________________________
The following data inside Main Stream is listed:
In Main Stream number: 2
Stream flow area = 0.265(Ac.)
Runoff from this stream = 1.940(CFS)
Time of concentration = 6.75 min.
Rainfall intensity = 6.296(In/Hr)
Summary of stream data:
5
Stream Flow rate TC Rainfall Intensity
No. (CFS) (min) (In/Hr)
1 18.537 7.49 5.890
2 1.940 6.75 6.296
Qmax(1) =
1.000 * 1.000 * 18.537) +
0.935 * 1.000 * 1.940) + = 20.352
Qmax(2) =
1.000 * 0.902 * 18.537) +
1.000 * 1.000 * 1.940) + = 18.656
Total of 2 main streams to confluence:
Flow rates before confluence point:
18.537 1.940
Maximum flow rates at confluence using above data:
20.352 18.656
Area of streams before confluence:
4.714 0.265
Results of confluence:
Total flow rate = 20.352(CFS)
Time of concentration = 7.485 min.
Effective stream area after confluence = 4.979(Ac.)
End of computations, total study area = 4.979 (Ac.)
6
Exhibit A
La Costa Town Square
POST DEVELOPMENT HYDRAULICS - MAIN SYSTEMS
Node PEAK FLOW DIA Area HGL dn/D VELOCITY
C.F.S.(IN) (SQ FT)(FPS)
202-103 4.29 36 7.07 288.31 >1 0.61
103-104 7.13 36 7.07 288.31 >1 1.01
Lateral North 6.40 12 0.79 288.31 >1 8.15
Lateral South0.71 12 0.79 288.31 >1 0.90
104-606 16.40 30 4.91 288.31 >1 3.34
104-106 0.90 36 7.07 288.31 >1 0.13
Node PEAK FLOW DIA PIPE Depth dn/D VELOCITY
C.F.S.(IN) SLOPE (FEET)(FPS)
MWS#1
MWS-106 0.90 12 8.05%0.20 0.20 8.05
106-107 0.90 12 11.38%0.18 0.18 9.07
502-107 1.20 18 97.50%0.11 0.07 20.33
107-108 2.10 18 2.00%0.38 0.25 5.94
Diversion Structure
606-604 16.40 18 5.17%0.91 0.61 14.58
600-604 2.20 18 17.75%0.23 0.15 13.24
604-605 18.60 18 14.58%0.72 0.48 22.30
605-108 18.60 18 1.50% FULL >1 10.53
D:\76882 La Costa Town Square\13 Reports\Hydrology\sewer5_gravity_offsite MH.xlsx 76882.25
D:\76882 La Costa Town Square\13 Reports\Hydrology\La Costa, Drainage Study 2022 0210.docx Page 12
EXHIBIT B
Inlet Summary
Exhibit "B"
Inlet No Basin
Basin Area
(Ac)Q (cfs)Inlet
Type
Inlet
Condition
Street
Grade
Depth
(ft)
Req'd
Opening
(ft)
Inlet
Length
(ft)
Inlet capacity
(cfs)Q bypass (cfs)
1 404 0.2645 1.43 Curb On Grade 10.6%0.19 5.5 7 1.6 0
2 215 0.1364 0.74 Curb Sump --0.4 5 6.8 0
3 201A, 201B 1.3943 7.56 Curb Sump --4.4 6 8.5 0
4 202 0.1568 0.85 Curb On Grade 2%0.21 3.1 5 1.1 0
5 102 0.0688 0.37 Curb On Grade 14.2%0.10 1.9 5 0.8 0
6 103, 104 0.2113 1.15 Curb On Grade 14.2%0.20 4.2 6 1.4 0
7 203 0.3691 2.00 Curb Sump --1.2 5 6.8 0
8 212 0.1408 0.76 Curb Sump --0.4 5 6.8 0
Type B Curb Inlet with 4" Local depression(a=0.33) for 10" curb face.
B Curb Inlet size is opening length (round up) + 1 foot
Passing Grade Sump Condition
Depth (y) based upon Gutter & Roadway Chart for 6" curb height Opening Height =(h) 6.2"
Qint = 0.7L (a+y)^1.5 Max Depth (H) = 10" curb face
Lreq'd = Q/(0.7*(a+y)^1.5)H/h ratio = 1.61
Q/L solved from Nomograph for Curb Inlet @ Sag
Inlet Capacity is based upon opening length & upstream depth Required Opening L = Q/1.7
Capacity is based upon max depth & actual opening
LA COSTA TOWN SQUARE PARCEL 3
CURB INLET DESIGN SUMMARY
D:\76882 La Costa Town Square\13 Reports\Hydrology\La Costa, Drainage Study 2022 0210.docx Page 13
EXHIBIT C
Detention Calculations
Annotated Excerpts CT-01-09 Drainage Study
Annotated Excerpts from
CT 01-09 Drainage Study
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
A construction revision to Drawing 205-2D to install a metal plate at the entrance of the
72 inch RCP will be processed with the City of Carlsbad prior to approval of Final Map
CT 01-09. See table below for comparisons of peak outflows for the box culverts and
two 72 inch RCPs.
Peak Flow
3.5' x 5' Opening in Box Culvert
(Top 1.5' Block with Metal Plate) per Addendum 585.9 cfs @ 255.3 Feet
to the Preliminary Hydrolof!V Study
Two 72" RCPs
with 3.2' High Opening 582.3 cfs@ 256.3 Feet
(Top 2.8' Blocked with Metal Plate)
Basin 2
The 100-year detained discharge from Basin 2 from the project site is 110.7 cfs. This
flow, includes existing flows from Rancho Santa Fe Road, will discharge to a proposed
detention facility southwest of the Commercial Site and west of the Office site just north
of La Costa A venue. The increase from the existing conditions discharge of 54.8 cfs will
be mitigated through on-site hydromodification as well as the proposed detention facility.
The detention basin in Basin 2 is designed to provide hydromodification for Drainage
Management Areas (DMA's) that provide treatment for runoff only, but not
hydromodification. The San Diego BMP Calculator Pond Sizer was used to size the
detention basin and orifices for hydromodification flow. See Attachment 8 for
hydromodification design for the detention basin.
The hydromodification flows from the detention basin will be controlled by two pipes (a
5-inch pipe at an invert of 266.19 foot elevation, and a 10-inch pipe at an invert of 268.39
foot elevation) through a 2.5-foot high concrete weir surrounding the 30-inch outlet pipe.
The bottom 2.5 feet of the detention basin will serve as temporary storage for the DMA's
without hydromodification. The maximum storage corresponding to the
hydromodification flow threshold is 0.687 ac-ft (29,904 ft3). Flows greater than the
hydromodification flow threshold will over top the 20-foot long concrete weir. The
detention basin analysis indicates that the peak 100-year flow is attenuated from 110.7 cfs
to 49.9 cfs. The maximum storage volume used is 1.301 ac-ft (56,672 ft\ with a
maximum water surface elevation at 5.4 feet from the bottom of the detention basin.
1:\00 IO I 7\_ Commercial\Stonnwater\Drainage\LCTS Comm_ Drainage Rpt. Doc
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SECTION3
HYDROLOGY -EXISTING CONDITION
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SECTION3
HYDROLOGY -EXISTING CONDITION
BASINC
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1017C.OUT slope or 'Z' of right channel bank= 2.000
Estimated mean flow rate at midpoint of channel= 40.664(CFS) Manning's 'N' = 0.015
Maximum depth of channel = l.OOO(Ft.)
Flow(q) thru subarea = 40.664(CFS)
Depth of flow= 0.900(Ft.), Average velocity= 16.143(Ft/s) channel flow top width= 4.599(Ft.) Flow Velocity= 16.14(Ft/s)
Travel time = 0.62 min.
Time of concentration= 17.62 min. critical depth= l.672(Ft.) Adding area flow to channel
user specified 'C' value of 0.350 given for subarea
Rainfall intensity= 3.274(In/Hr) for a 100.0 year storm
Runoff coefficient used for sub-area, Rational method,Q=KCIA c = 0.350 subarea runoff= 5.615(CFS) for 4.900(Ac.)
Total runoff= 39.287(CFS) Total area= 16.70(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 302.000 to Point/Station 302.000 **** SUBAREA FLOW ADDITION****
User specified 'C' value of 0.350 given for subarea Time of concentration= 17.62 min.
Rainfall intensity= 3.274(In/Hr) for a 100.0 year storm
Runoff coefficient used for sub-area, Rational method,Q=KCIA, c = 0.350 subarea runoff= 15.469(CFS) for 13.500(Ac.)
Total runoff= 54.757(CFS) Total area= 30.20(Ac.) End of computations, total study area= 30.20 (Ac.)
Page 2
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--~ ~------------,
SECTION 4
HYDROLOGY -DEVELOPED CONDITION
BASIN 2
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San Diego County Rational Hydrology Program
CIVILCADD/CIVILDESIGN Engineering Software, (c)1991-2004 Version 7.4
Rational method hydrology program based on
San Diego County Flood Control Division 2003 hydrology manual
Rational Hydrology Study Date: 04/27/12
La Costa Town Square
Developed Condition Hydrology
Basin No. 2
********* Hydrology Study Control Information**********
Program License Serial Number 5014
Rational hydrology study storm event year is
English (in-lb) input data Units used
Map data precipitation entered:
6 hour, precipitation(inches) = 2.800
24 hour precipitation(inches) = 5.100
P6/P24 = 54.9%
San Diego hydrology manual 'C' values used
100.0
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2000.000 to Point/Station 2001.000
**** INITIAL AREA EVALUATION****
Decimal fraction soil group A
Decimal fraction soil group B
Decimal fraction soil group C
Decimal fraction soil group D =
[COMMERCIAL area type
(General Commercial )
Impervious value, Ai= 0.850
Sub-Area C Value= 0.820
0.000
0.000
0.000
1.000
Initial subarea total flow distance
Highest elevation= 334.700(Ft.)
Lowest elevation= 331.300(Ft.)
306.000(Ft.)
Elevation difference= 3.400(Ft.) Slope= 1.111 %
INITIAL AREA TIME OF CONCENTRATION CALCULATIONS:
The maximum overland flow distance is 60.00 (Ft)
for the top area slope value of 1.11 %, in a development type of
General Commercial
In Accordance With Figure 3-3
Initial Area Time of Concentration= 3.77 minutes
TC= [l.8*(1.l-C)*distance(Ft.)A.5)/(% slopeA(l/3)]
TC= [1.8*(1.1-0.8200)*( 60.000A.5)/( 1.lllA(l/3)]= 3.77
The initial area total distance of 306.00 (Ft.) entered leaves a
remaining distance of 246.00 (Ft.)
Using Figure 3-4, the travel time for this distance is
for a distance of 246.00 (Ft.) and a slope of 1.11 %
3.06 minutes
with an elevation difference of 2.73(Ft.) from the end of the top area
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Tt = [ll.9*length(Mi}A3}/(elevation change(Ft.}))A.385 *60(min/hr}
= 3.062 Minutes
Tt=[(ll.9*0.0466A3)/( 2.73)]A.385= 3.06
Total initial area Ti= 3.77 minutes from
3.06 minutes from the Figure 3-4 formula
Rainfall intensity (I} = 6.032(In/Hr)
Effective runoff coefficient used for area
Subarea runoff= 4.402(CFS}
Figure 3-3 formula plus
6.83 minutes
for a 100.0 year storm
(Q=KCIA} is C = 0.820
Total initial stream area= 0.890(Ac.}
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2001.000 to Point/Station 2002.000
**** PIPEFLOW TRAVEL TIME (Program estimated size) ****
Upstream point/station elevation= 329.000(Ft.}
Downstream point/station elevation= 325.000(Ft.}
Pipe length = 120.00(Ft.} Manning's N = 0.011
No. of pipes= 1 Required pipe flow 4.402(CFS}
Nearest computed pipe diameter = 12.00(In.)
Calculated individual pipe flow = 4.402(CFS)
Normal flow depth in pipe= 6.51(In.)
Flow top width inside pipe= ll.96(In.)
Critical Depth= 10.56(In.)
Pipe flow velocity= 10.12(Ft/s)
Travel time through pipe= 0.20 min.
Time of concentration (TC) = 7.03 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2002.000 to Point/Station 2002.000
**** SUBAREA FLOW ADDITION****
Decimal fraction soil group A 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C 0.000
Decimal fraction soil group D = 1.000
[COMMERCIAL area type
(General Commercial )
Impervious value, Ai = 0.850
Sub-Area C Value = 0.820
Time of concentration= 7.03 min.
Rainfall intensity= 5.922(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.820 CA= 1.066
Subarea runoff 1.911(CFS) for 0.410(Ac.)
Total runoff= 6.313(CFS) Total area= l.300(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2002.000 to Point/Station 2002.000
**** SUBAREA FLOW ADDITION****
User specified 'C' value of 0.850 given for subarea
Time of concentration= 7.03 min.
Rainfall intensity= 5.922(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.850 CA= 1.454
Subarea runoff -2.295(CFS} for 0.410(Ac.}
Total runoff= 8.608(CFS) Total area= l.710(Ac.)
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'
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2002.000 to Point/Station 2003.000
**** PIPEFLOW TRAVEL TIME (Program estimated size) ****
Upstream point/station elevation= 325.000(Ft.)
Downstream point/station elevation= 324.400(Ft.)
Pipe length 30.00(Ft.) Manning's N = 0.011
No. of pipes= 1 Required pipe flow = 8.608(CFS)
Nearest computed pipe diameter = 15.00(In.)
Calculated individual pipe flow = 8.608(CFS)
Normal flow depth in pipe= 10.13(In.)
Flow top width inside pipe= 14.0S(In.)
Critical Depth= 13.70(In.)
Pipe flow velocity= 9.77(Ft/s)
Travel time through pipe= 0.05 min.
Time of concentration (TC) = 7.08 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2003.000 to Point/Station 2003.000
**** SUBAREA FLOW ADDITION****
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C 0.000
Decimal fraction soil group D = 1.000
[COMMERCIAL area type
(General Commercial )
Impervious value, Ai = 0.850
Sub-Area C Value = 0.820
Time of concentration= 7.08 min.
Rainfall intensity= 5.895(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.849 CA= 1.527
Subarea runoff= 0.395(CFS) for 0.090(Ac.)
Total runoff= 9.003(CFS) Total area= l.800(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2003.000 to Point/Station 2004.000
**** PIPEFLOW TRAVEL TIME (Program estimated size) ****
Upstream point/station elevation= 324.400(Ft.)
Downstream point/station elevation= 323.l00(Ft.)
Pipe length = 62.00(Ft.) Manning's N = 0.011
No. of pipes= 1 Required pipe flow 9.003(CFS)
Nearest computed pipe diameter 15.00(In.)
Calculated individual pipe flow 9.003(CFS)
Normal flow depth in pipe= 10.29(In.)
Flow top width inside pipe= 13.92(In.)
Critical Depth= 13.86(In.)
Pipe flow velocity= 10.04(Ft/s)
Travel time through pipe= 0.10 min.
Time of concentration (TC) = 7.18 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2004.000 to Point/Station 2004.000
**** SUBAREA FLOW ADDITION****
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Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[COMMERCIAL area type
(General Commercial )
Impervious value, Ai = 0.850
Sub-Area C Value = 0.820
Time of concentration= 7.18 min.
Rainfall intensity= 5.840(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.846 CA= 1.650
Subarea runoff= 0.635(CFS) for 0.150(Ac.)
Total runoff= 9.638(CFS) Total area= 1.950(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2004.000 to Point/Station 2005.000
**** PIPEFLOW TRAVEL TIME (Program estimated size) ****
Upstream point/station elevation= 323.l00(Ft.)
Downstream point/station elevation= 321.l00(Ft.)
Pipe length = 99.00(Ft.) Manning's N = 0.011
No. of pipes= 1 Required pipe flow = 9.638(CFS)
Nearest computed pipe diameter 15.00(In.)
Calculated individual pipe flow = 9.638(CFS)
Normal flow depth in pipe= 11.00(In.)
Flow top width inside pipe= 13.26(In.)
Critical Depth= 14.l0(In.)
Pipe flow velocity= 9.99(Ft/s)
Travel time through pipe= 0.17 min.
Time of concentration (TC) = 7.35 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2005.000 to Point/Station 2005.000
**** SUBAREA FLOW ADDITION****
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C 0.000
Decimal fraction soil group D = 1.000
[COMMERCIAL area type
(General Commercial )
Impervious value, Ai = 0.850
Sub-Area C Value = 0.820
Time of concentration= 7.35 min.
Rainfall intensity= 5.755(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.844 CA= 1.773
Subarea runoff 0.568(CFS) for 0.150(Ac.)
Total runoff= 10.205(CFS) Total area= 2.l00(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2005.000 to Point/Station 2006.000
**** PIPEFLOW TRAVEL TIME (Program estimated size) ****
Upstream point/station elevation= 321.l00(Ft.)
Downstream point/station elevation 318.S00(Ft.)
Pipe length 115.00(Ft.) Manning's N = 0.011
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No. of pipes= 1 Required pipe flow = 10.205(CFS)
Nearest computed pipe diameter 15.00(In.)
Calculated individual pipe flow = 10.205(CFS)
Normal flow depth in pipe= ll.63(In.)
Flow top width inside pipe= 12.53(In.)
Critical depth could not be calculated.
Pipe flow velocity= 10.0l(Ft/s)
Travel time through pipe= 0.19 min.
Time of concentration (TC) = 7.54 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2000.000 to Point/Station 2006.000
**** CONFLUENCE OF MAIN STREAMS****
The following data inside Main Stream is listed:
In Main Stream number: 1
Stream flow area= 2.l00(Ac.)
Runoff from this stream= 10.205(CFS)
Time of concentration= 7.54 min.
Rainfall intensity= 5.660(In/Hr)
Program is now starting with Main Stream No. 2
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2006.100 to Point/Station 2006.200
**** INITIAL AREA EVALUATION****
Decimal fraction soil group A=
Decimal fraction soil group B
Decimal fraction soil group C =
Decimal fraction soil group D =
[COMMERCIAL area type
(General Commercial )
Impervious value, Ai= 0.850
Sub-Area C Value= 0.820
0.000
0.000
0.000
1.000
Initial subarea total flow distance = 110.000(Ft.)
Highest elevation= 330.400(Ft.)
Lowest elevation= 329.500(Ft.)
Elevation difference= 0.900(Ft.) Slope= 0.818 %
INITIAL AREA TIME OF CONCENTRATION CALCULATIONS:
The maximum overland flow distance is 60.00 (Ft)
for the top area slope value of 0.82 %, in a development type of
General Commercial
In Accordance With Figure 3-3
Initial Area Time of Concentration= 4.17 minutes
TC= [1.8*(1.l-C)*distance(Ft.)A.5)/(% slopeA(l/3)]
TC= [l.8*(1.1-0.8200)*( 60.000A.5)/( 0.818A(l/3)]= 4.17
The initial area total distance of 110.00 (Ft.) entered leaves a
remaining distance of 50.00 (Ft.)
Using Figure 3-4, the travel time for this distance is
for a distance of 50.00 (Ft.) and a slope of 0.82 %
1.01 minutes
with an elevation difference of 0.41(Ft.) from the end of the top
Tt = [11.9*length(Mi)A3)/(elevation change(Ft.) )]A.385 *60(min/hr)
= 1.010 Minutes
Tt=[(ll.9*0.0095A3)/( 0.41)]A.385= 1.01
Total initial area Ti= 4.17 minutes from
1.01 minutes from the Figure 3-4 formula
Rainfall intensity (I) = 7.207(In/Hr)
Effective runoff coefficient used for area
Subarea runoff= 1.182(CFS)
Figure 3-3 formula plus
= 5.18 minutes
for a 100.0 year storm
(Q=KCIA) is C = 0.820
area
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Total initial stream area= 0.200(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2006.200 to Point/Station 2006.300
**** PIPEFLOW TRAVEL TIME (Program estimated size) ****
Upstream point/station elevation= 323.700(Ft.)
Downstream point/station elevation= 320.900(Ft.)
Pipe length = 119.00(Ft.) Manning's N = 0.011
No. of pipes= 1 Required pipe flow = 1.182(CFS)
Nearest computed pipe diameter = 9.00(In.)
Calculated individual pipe flow = l.182(CFS)
Normal flow depth in pipe= 3.93(In.)
Flow top width inside pipe= 8.93(In.)
Critical Depth= 6.00(In.)
Pipe flow velocity= 6.39(Ft/s)
Travel time through pipe= 0.31 min.
Time of concentration (TC) = 5.50 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2006.300 to Point/Station 2006.300
**** SUBAREA FLOW ADDITION****
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
(COMMERCIAL area type
(General Commercial )
Impervious value, Ai = 0.850
Sub-Area C Value = 0.820
Time of concentration= 5.50 min.
Rainfall intensity= 6.941(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.820 CA= 0.443
Subarea runoff 1.892(CFS) for 0.340(Ac.)
Total runoff= 3.074(CFS) Total area= 0.540(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2006.300 to Point/Station 2006.400
**** PIPEFLOW TRAVEL TIME (Program estimated size) ****
Upstream point/station elevation= 320.900(Ft.)
Downstream point/station elevation= 319.200(Ft.)
Pipe length = 40.00(Ft.) Manning's N = 0.011
No. of pipes= 1 Required pipe flow = 3.074(CFS)
Nearest computed pipe diameter = 9.00(In.)
Calculated individual pipe flow 3.074(CFS)
Normal flow depth in pipe= 5.88(In.)
Flow top width inside pipe= 8.56(In.)
Critical depth could not be calculated.
Pipe flow velocity= 10.04(Ft/s)
Travel time through pipe= 0.07 min.
Time of concentration (TC) = 5.56 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2006.400 to Point/Station 2006.400
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**** SUBAREA FLOW ADDITION****
Decimal fraction soil group A = 0.000
Decimal fraction soil group B 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D 1.000
[COMMERCIAL area type
(General Commercial )
Impervious value, Ai = 0.850
Sub-Area C Value= 0.820
Time of concentration= 5.56 min.
Rainfall intensity= 6.888(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.820 CA= 0.566
Subarea runoff= 0.823(CFS) for 0.150(Ac.)
Total runoff= 3.897(CFS) Total area= 0.690(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2006.400 to Point/Station 2006.000
**** PIPEFLOW TRAVEL TIME (Program estimated size) ****
Upstream point/station elevation= 319.200(Ft.)
Downstream point/station elevation= 318.800(Ft.)
Pipe length = 14.00(Ft.) Manning's N = 0.011
No. of pipes= 1 Required pipe flow = 3.897(CFS)
Nearest computed pipe diameter = 12.00(In.)
Calculated individual pipe flow 3.897(CFS)
Normal flow depth in pipe= 6.33(In.)
Flow top width inside pipe= 11.98(In.)
Critical Depth= 10.06(In.)
Pipe flow velocity= 9.27(Ft/s)
Travel time through pipe= 0.03 min.
Time of concentration (TC) = 5.59 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2006.400 to Point/Station 2006.000
**** CONFLUENCE OF MAIN STREAMS****
The following data inside Main Stream is listed:
In Main Stream number: 2
Stream flow area= 0.690(Ac.)
Runoff from this stream= 3.897(CFS)
Time of concentration= 5.59 min.
Rainfall intensity= 6.868(In/Hr)
Summary of stream data:
Stream Flow rate TC Rainfall Intensity
No. (CFS) (min) (In/Hr)
1 10.205 7.54 5.660
2 3.897 5.59 6.868
Qmax(l) =
1.000 * 1.000 * 10.205) +
0.824 * 1.000 * 3.897) + = 13. 417
Qmax(2) =
1.000 * 0.741 * 10.205) +
1. 000 * 1. 000 * 3.897) + 11. 459
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Time of concentration= 7.65 min.
Rainfall intensity= 5.606(In/Hr)
Program is now starting with Main Stream No. 2
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2007.100 to Point/Station 2007.200
**** INITIAL AREA EVALUATION****
Decimal fraction soil
Decimal fraction soil
Decimal fraction soil
group A
group B
group C
= 0.000
= 0.000
= 0.000
Decimal fraction soil group D =
[COMMERCIAL area type
1.000
(General Commercial )
Impervious value, Ai= 0.850
Sub-Area C Value= 0.820
Initial subarea total flow distance =
Highest elevation= 329.900(Ft.)
Lowest elevation= 328.800(Ft.)
62.000(Ft.)
Elevation difference l.l00(Ft.) Slope= 1.774 %
INITIAL AREA TIME OF CONCENTRATION CALCULATIONS:
The maximum overland flow distance is 75.00 (Ft)
for the top area slope value of 1.77 %, in a development
General Commercial
In Accordance With Table 3-2
Initial Area Time of Concentration= 3.60 minutes
(for slope value of 2.00 %)
Calculated TC of 3.600 minutes is less than 5 minutes,
type of
resetting TC to 5.0 minutes for rainfall intensity calculations
Rainfall intensity (I) = 7.377(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for area (Q=KCIA) is C = 0.820
Subarea runoff= 0.665(CFS)
Total initial stream area= 0.ll0(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2007.200 to Point/Station 2007.300
**** PIPEFLOW TRAVEL TIME (Program estimated size) ****
Upstream point/station elevation= 324.400(Ft.)
Downstream point/station elevation= 317.600(Ft.)
Pipe length 76.00(Ft.) Manning's N = 0.011
No. of pipes= 1 Required pipe flow = 0.665(CFS)
Nearest computed pipe diameter = 6.00(In.)
Calculated individual pipe flow = 0.665(CFS)
Normal flow depth in pipe= 2.40(In.)
Flow top width inside pipe= 5.88(In.)
Critical Depth= 4.95(In.)
Pipe flow velocity= 9.ll(Ft/s)
Travel time through pipe= 0.14 min.
Time of concentration (TC) = 3.74 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2007.300 to Point/Station 2007.300
**** SUBAREA FLOW ADDITION****
Decimal fraction soil group A=
Decimal fraction soil group B
Decimal fraction soil group C
0.000
0.000
0.000
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Decimal fraction soil group D = 1.000
[COMMERCIAL area type
(General Commercial )
Impervious value, Ai= 0.850
Sub-Area C Value= 0.820
Time of concentration= 3.74 min.
Rainfall intensity= 7.377(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.820 CA= 0.180
Subarea runoff= 0.665(CFS) for 0.ll0(Ac.)
Total runoff= 1.331(CFS) Total area= 0.220(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2007.300 to Point/Station 2007.000
**** PIPEFLOW TRAVEL TIME (Program estimated size) ****
Upstream point/station elevation= 317.600(Ft.)
Downstream point/station elevation= 317.400(Ft.)
Pipe length = 14.00(Ft.) Manning's N = 0.011
No. of pipes= 1 Required pipe flow = 1.331(CFS)
Nearest computed pipe diameter = 9.00(In.)
Calculated individual pipe flow = 1.331(CFS)
Normal flow depth in pipe= 4.86(In.)
Flow top width inside pipe= 8.97(In.)
Critical Depth= 6.38(In.)
Pipe flow velocity= 5.46(Ft/s)
Travel time through pipe= 0.04 min.
Time of concentration (TC) = 3.78 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2007.300 to Point/Station 2007.000
**** CONFLUENCE OF MAIN STREAMS****
The following data inside Main Stream is listed:
In Main Stream number: 2
Stream flow area= 0.220(Ac.)
Runoff from this stream l.331(CFS)
Time of concentration= 3.78 min.
Rainfall intensity= 7.377(In/Hr)
Summary of stream data:
Stream Flow rate TC Rainfall Intensity
No. (CFS) (min) (In/Hr)
1 13.941 7.65 5.606
2 1.331 3.78 7.377
Qmax(l)
1.000 * 1.000 * 13.941) +
0.760 * 1.000 * 1.331) + = 14.953
Qmax(2) =
1.000 * 0.494 * 13.941) +
1.000 * 1.000 * 1.331) + = 8.221
Total of 2 main streams to confluence:
Flow rates before confluence point:
13.941 1.331
Maximum flow rates at confluence using above data:
14.953 8.221
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In Accordance With Figure 3-3
Initial Area Time of Concentration= 3.50 minutes
TC= [1.8*{1.l-C)*distance{Ft.)A.5)/(% slopeA{l/3)]
TC= [1.8*(1.1-0.8200)*{ 75.000A.5)/( 1.944A(l/3)]= 3.50
The initial area total distance of 180.00 (Ft.) entered leaves a
remaining distance of 105.00 {Ft.)
Using Figure 3-4, the travel time for this distance is 1.28 minutes
for a distance of 105.00 (Ft.) and a slope of 1.94 %
with an elevation difference of 2.04{Ft.) from the end of the top area
Tt = [11.9*length{Mi)A3)/{elevation change{Ft.))]A.385 *60{min/hr)
= 1.282 Minutes
Tt=[(ll.9*0.0199A3)/{ 2.04)]A.385= 1.28
Total initial area Ti= 3.50 minutes from Figure 3-3 formula plus
1.28 minutes from the Figure 3-4 formula= 4.78 minutes
Calculated TC of 4.779 minutes is less than 5 minutes,
resetting TC to 5.0 minutes for rainfall intensity calculations
Rainfall intensity (I) = 7.377{In/Hr) for a 100.0 year storm
Effective runoff coefficient used for area {Q=KCIA) is C = 0.820
Subarea runoff= 1.028(CFS)
Total initial stream area= 0.170(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2008.200 to Point/Station 2008.300
**** PIPEFLOW TRAVEL TIME (Program estimated size) ****
Upstream point/station elevation= 322.200(Ft.)
Downstream point/station elevation= 320.400(Ft.)
Pipe length 131.00{Ft.) Manning's N = 0.013
No. of pipes= 1 Required pipe flow = 1.028(CFS)
Nearest computed pipe diameter 9.00(In.)
Calculated individual pipe flow = 1.028(CFS)
Normal flow depth in pipe= 4.66{In.)
Flow top width inside pipe= 8.99(In.)
Critical Depth= 5.59{In.)
Pipe flow velocity= 4.45{Ft/s)
Travel time through pipe= 0.49 min.
Time of concentration {TC) = 5.27 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2008.300 to Point/Station 2008.300
**** SUBAREA FLOW ADDITION****
Decimal fraction soil group A 0.000
Decimal fraction soil group B 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D 1.000
[COMMERCIAL area type
(General Commercial )
Impervious value, Ai = 0.850
Sub-Area C Value = 0.820
Time of concentration= 5.27 min.
Rainfall intensity= 7.132{In/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area
{Q=KCIA) is C = 0.820 CA= 0.353
Subarea runoff= 1.486{CFS) for 0.260(Ac.)
Total runoff= 2.515{CFS) Total area= 0.430{Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
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Process from Point/Station 2008.300 to Point/Station 2008.400
**** PIPEFLOW TRAVEL TIME (Program estimated size) ****
Upstream point/station elevation= 320.400(Ft.)
Downstream point/station elevation= 319.000(Ft.)
Pipe length = 90.00(Ft.) Manning's N = 0.013
No. of pipes= 1 Required pipe flow = 2.515(CFS)
Nearest computed pipe diameter = 12.00(In.)
Calculated individual pipe flow = 2.515(CFS)
Normal flow depth in pipe= 6.46(In.)
Flow top width inside pipe= 11.96(In.)
Critical Depth= 8.15(In.)
Pipe flow velocity= 5.83(Ft/s)
Travel time through pipe= 0.26 min.
Time of concentration (TC) = 5.53 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2008.400 to Point/Station 2008.500
**** IRREGULAR CHANNEL FLOW TRAVEL TIME****
Estimated mean flow rate at midpoint of channel=
Depth of flow= 0.ll0(Ft.), Average velocity=
******* Irregular Channel Data***********
Information entered for subchannel number 1 :
Point number 'X' coordinate 'Y' coordinate
1 0.00 4.70
2 10.00 0.00
3 32.60 0.00
4 56.30 12.00
Manning's 'N' friction factor 0.035
Sub-Channel flow = 2.546(CFS)
flow top width= 23.0S0(Ft.)
velocity= 1.017(Ft/s)
area= 2.503(Sq.Ft)
Froude number= 0.544
Upstream point elevation=
Downstream point elevation=
Flow length= 36.000(Ft.)
Travel time = 0.59 min.
319.000(Ft.)
318.600(Ft.)
Time of concentration= 6.12 min.
Depth of flow= 0.ll0(Ft.)
Average velocity= 1.017(Ft/s)
Total irregular channel flow= 2.546(CFS)
Irregular channel normal depth above invert elev. =
Average velocity of channel(s) l.017(Ft/s)
Adding area flow to channel
User specified 'C' value of 0.490 given for subarea
The area added to the existing stream causes a
a lower flow rate of Q = 2.444(CFS)
2.546(CFS)
l.017(Ft/s)
0.ll0(Ft.)
therefore the upstream flow rate of Q = 2.515(CFS) is being used
Rainfall intensity= 6.478(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.490 CA= 0.377
Subarea runoff= 0.000(CFS) for 0.340(Ac.)
Total runoff= 2.515(CFS) Total area
Depth of flow= 0.109(Ft.), Average velocity=
0.770(Ac.)
1.012(Ft/s)
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++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2008.500 to Point/Station 2008.000
**** PIPEFLOW TRAVEL TIME (Program estimated size) ****
Upstream point/station elevation= 314.500(Ft.)
Downstream point/station elevation= 313.300(Ft.)
Pipe length = 99.00(Ft.) Manning's N = 0.011
No. of pipes= 1 Required pipe flow = 2.515(CFS)
Nearest computed pipe diameter = 12.00(In.)
Calculated individual pipe flow = 2.515(CFS)
Normal flow depth in pipe= 6.30(In.)
Flow top width inside pipe= 11.99(In.)
Critical Depth= 8.15(In.)
Pipe flow velocity= 6.02(Ft/s)
Travel time through pipe= 0.27 min.
Time of concentration (TC) = 6.39 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2008.500 to Point/Station 2008.000
**** CONFLUENCE OF MAIN STREAMS****
The following data inside Main Stream is listed:
In Main Stream number: 2
Stream flow area= 0.770(Ac.)
Runoff from this stream= 2.515(CFS)
Time of concentration=
Rainfall intensity=
Summary of stream data:
6.39 min.
6.298(In/Hr)
Stream Flow rate TC Rainfall Intensity
No. (CFS) (min) (In/Hr)
1 14.953 8.16 5.380
2 2.515 6.39 6.298
Qmax(l)
1.000 * 1.000 * 14.953) +
0.854 * 1.000 * 2.515) + 17.101
Qmax(2) =
1.000 * 0.783 * 14.953) +
1.000 * 1.000 * 2.515) + 14.227
Total of 2 main streams to confluence:
Flow rates before confluence point:
14.953 2.515
Maximum flow rates at confluence using above data:
17.101 14.227
Area of streams before confluence:
3.190 0.770
Results of confluence:
Total flow rate= 17.l0l(CFS)
Time of concentration 8.158 min.
Effective stream area after confluence = 3.960(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2008.000 to Point/Station 2009.000
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**** PIPEFLOW TRAVEL TIME (Program estimated size) ****
Upstream point/station elevation= 313.300(Ft.)
Downstream point/station elevation= 312.400(Ft.)
Pipe length = 89.00(Ft.) Manning's N = 0.013
No. of pipes= 1 Required pipe flow 17.l0l(CFS)
Nearest computed pipe diameter = 24.00(In.)
Calculated individual pipe flow = 17.l0l(CFS)
Normal flow depth in pipe= 15.54(In.)
Flow top width inside pipe= 22.93(In.)
Critical Depth= 17.89(In.)
Pipe flow velocity= 7.95(Ft/s)
Travel time through pipe= 0.19 min.
Time of concentration (TC) = 8.34 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2009.000 to Point/Station 2009.000
**** SUBAREA FLOW ADDITION****
Decimal fraction soil group A= 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[COMMERCIAL area type
(General Commercial )
Impervious value, Ai= 0.850
Sub-Area C Value= 0.820
The area added to the existing stream causes a
a lower flow rate of Q = 16.749(CFS)
therefore the upstream flow rate of Q = 17.l0l(CFS) is being used
Time of concentration= 8.34 min.
Rainfall intensity= 5.302(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.771 CA= 3.159
Subarea runoff 0.000(CFS) for 0.140(Ac.)
Total runoff= 17.l0l(CFS) Total area= 4.l00(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2009.000 to Point/Station 2010.000
**** PIPEFLOW TRAVEL TIME (Program estimated size) ****
Upstream point/station elevation= 312.400(Ft.)
Downstream point/station elevation= 312.200(Ft.)
Pipe length 13.40(Ft.) Manning's N = 0.013
No. of pipes= 1 Required pipe flow 17.l0l(CFS)
Nearest computed pipe diameter = 21.00(In.)
Calculated individual pipe flow = 17.l0l(CFS)
Normal flow depth in pipe= 15.33(In.)
Flow top width inside pipe= 18.65(In.)
Critical Depth= 18.19(In.)
Pipe flow velocity= 9.08(Ft/s)
Travel time through pipe= 0.02 min.
Time of concentration (TC) = 8.37 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2010.000 to Point/Station 2010.000
**** SUBAREA FLOW ADDITION****
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Decimal fraction soil group A = 0.000
Decimal fraction soil group B 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1. 000
[COMMERCIAL area type
(General Commercial )
Impervious value, Ai = 0.850
Sub-Area C Value = 0.820
Time of concentration= 8.37 min.
Rainfall intensity= 5.292(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.773 CA= 3.323
Subarea runoff= 0.485(CFS) for 0.200(Ac.)
Total runoff= 17.585(CFS) Total area= 4.300(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2010.000 to Point/Station 2011.000
**** PIPEFLOW TRAVEL TIME (Program estimated size) ****
Upstream point/station elevation= 312.200(Ft.)
Downstream point/station elevation 311.960(Ft.)
Pipe length = 26.80(Ft.) Manning's N = 0.013
No. of pipes= 1 Required pipe flow = 17.585(CFS)
Nearest computed pipe diameter = 24.00(In.)
Calculated individual pipe flow = 17.585(CFS)
Normal flow depth in pipe= 16.55(In.)
Flow top width inside pipe= 22.21(In.)
Critical Depth= 18.13(In.)
Pipe flow velocity= 7.60(Ft/s)
Travel time through pipe= 0.06 min.
Time of concentration (TC) = 8.43 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2000.000 to Point/Station 2011.000
**** CONFLUENCE OF MAIN STREAMS****
The following data inside Main Stream is listed:
In Main Stream number: 1
Stream flow area= 4.300(Ac.)
Runoff from this stream= 17.585(CFS)
Time of concentration= 8.43 min.
Rainfall intensity= 5.268(In/Hr)
Program is now starting with Main Stream No. 2
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2011.100 to Point/Station 2011.200
**** INITIAL AREA EVALUATION****
Decimal fraction soil group A = 0.000
Decimal fraction soil group B 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1. 000
[COMMERCIAL area type
(General Commercial )
Impervious value, Ai = 0.850
Sub-Area C Value = 0.820
Initial subarea total flow distance = 214.000(Ft.)
Highest elevation= 329.200(Ft.)
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Lowest elevation= 324.600(Ft.)
Elevation difference= 4.600(Ft.) Slope= 2.150 %
INITIAL AREA TIME OF CONCENTRATION CALCULATIONS:
The maximum overland flow distance is 75.00 (Ft)
for the top area slope value of 2.15 %, in a development type of
General Commercial
In Accordance With Figure 3-3
Initial Area Time of Concentration= 3.38 minutes
TC= (1.8*(1.l-C)*distance(Ft.)A.5)/(% slopeA(l/3)]
TC= [l.8*(1.1-0.8200)*( 75.000A.5)/( 2.150A(l/3)]= 3.38
The initial area total distance of 214.00 (Ft.) entered leaves a
remaining distance of 139.00 (Ft.)
Using Figure 3-4, the travel time for this distance is 1.53 minutes
for a distance of 139.00 (Ft.) and a slope of 2.15 %
with an elevation difference of 2.99(Ft.) from the end of the top area
Tt = [11.9*length(Mi)A3)/(elevation change(Ft.))]A.385 *60(min/hr)
1.530 Minutes
Tt=[(ll.9*0.0263A3)/( 2.99)]A.385= 1.53
Total initial area Ti= 3.38 minutes from Figure 3-3 formula plus
1.53 minutes from the Figure 3-4 formula= 4.91 minutes
Calculated TC of 4.912 minutes is less than 5 minutes,
resetting TC to 5.0 minutes for rainfall intensity calculations
Rainfall intensity (I} = 7.377(In/Hr} for a 100.0 year storm
Effective runoff coefficient used for area (Q=KCIA} is C = 0.820
Subarea runoff= 1.633(CFS)
Total initial stream area= 0.270(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2011.200 to Point/Station 2011.300
**** PIPEFLOW TRAVEL TIME (Program estimated size) ****
Upstream point/station elevation= 319.600(Ft.)
Downstream point/station elevation 317.700(Ft.)
Pipe length 73.00(Ft.) Manning's N = 0.011
No. of pipes= 1 Required pipe flow = l.633(CFS)
Nearest computed pipe diameter = 9.00(In.}
Calculated individual pipe flow l.633(CFS)
Normal flow depth in pipe= 4.59(In.}
Flow top width inside pipe= 9.00(In.)
Critical Depth= 7.05(In.)
Pipe flow velocity= 7.20(Ft/s)
Travel time through pipe= 0.17 min.
Time of concentration (TC) = 5.08 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2011.300 to Point/Station 2011.300
**** SUBAREA FLOW ADDITION****
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[COMMERCIAL area type
(General Commercial }
Impervious value, Ai = 0.850
Sub-Area C Value = 0.820
Time of concentration= 5.08 min.
Rainfall intensity= 7.301(In/Hr} for a 100.0 year storm
Effective runoff coefficient used for total area
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(Q=KCIA) is C = 0.820
Subarea runoff=
CA= 0.312
0.642(CFS) for 0.ll0(Ac.)
Total runoff= 2.275(CFS) Total area= 0.380(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2011.300 to Point/Station 2011.400
**** PIPEFLOW TRAVEL TIME (Program estimated size) ****
Upstream point/station elevation= 317.700(Ft.)
Downstream point/station elevation= 312.600(Ft.)
Pipe length = 137.S0(Ft.) Manning's N = 0.011
No. of pipes= 1 Required pipe flow = 2.275(CFS)
Nearest computed pipe diameter 9.00(In.)
Ca1culated individual pipe flow 2.275(CFS)
Normal flow depth in pipe= 5.04(In.)
Flow top width inside pipe= 8.93(In.)
Critical Depth= 8.08(In.)
Pipe flow velocity= 8.92(Ft/s)
Travel time through pipe= 0.26 min.
Time of concentration (TC) = 5.34 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2011.400 to Point/Station 2011.400
**** SUBAREA FLOW ADDITION****
Decimal fraction soil group A 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[COMMERCIAL area type
(General Commercial )
Impervious value, Ai = 0.850
Sub-Area C Value = 0.820
Time of concentration= 5.34 min.
Rainfall intensity= 7.073(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.820 CA= 0.443
Subarea runoff 0.857(CFS) for 0.160(Ac.)
Total runoff= 3.132(CFS) Total area= 0.540(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2011.400 to Point/Station 2011.000
**** PIPEFLOW TRAVEL TIME (Program estimated size) ****
Upstream point/station elevation= 312.600(Ft.)
Downstream point/station elevation 311.960(Ft.)
Pipe length = 15.40(Ft.) Manning's N = 0.011
No. of pipes= 1 Required pipe flow = 3.132(CFS)
Nearest computed pipe diameter = 9.00(In.)
Calculated individual pipe flow = 3.132(CFS)
Normal flow depth in pipe= 6.0l(In.)
Flow top width inside pipe= 8.48(In.)
Critical depth could not be calculated.
Pipe flow velocity= 9.99(Ft/s)
Travel time through pipe= 0.03 min.
Time of concentration (TC) = 5.36 min.
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++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2011.400 to Point/Station 2011.000
**** CONFLUENCE OF MAIN STREAMS****
The following data inside Main Stream is listed:
In Main Stream number: 2
Stream flow area= 0.540(Ac.)
Runoff from this stream= 3.132(CFS)
Time of concentration= 5.36 min.
Rainfall intensity= 7.05l(In/Hr)
Summary of stream data:
Stream Flow rate TC Rainfall Intensity
No. (CFS) (min) (In/Hr)
1 17.585 8.43 5.268
2 3.132 5.36 7.051
Qmax(l) =
1.000 * 1.000 * 17.585) +
0.747 * 1.000 * 3.132) + = 19.925
Qmax(2) =
1.000 * 0.636 * 17.585) +
1.000 * 1.000 * 3.132) + = 14.323
Total of 2 main streams to confluence:
Flow rates before confluence point:
17.585 3.132
Maximum flow rates at confluence using above data:
19.925 14.323
Area of streams before confluence:
4.300 0.540
Results of confluence:
Total flow rate= 19.925(CFS)
Time of concentration= 8.428 min.
Effective stream area after confluence 4.840(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2011.000 to Point/Station 2012.000
**** PIPEFLOW TRAVEL TIME (Program estimated size) ****
Upstream point/station elevation= 311.960(Ft.)
Downstream point/station elevation 311.l00(Ft.)
Pipe length = 37.00(Ft.) Manning"s N = 0.013
No. of pipes= 1 Required pipe flow 19.925(CFS)
Nearest computed pipe diameter 21.00(In.)
Calculated individual pipe flow = 19.925(CFS)
Normal flow depth in pipe= 14.53(In.)
Flow top width inside pipe= 19.39(In.)
Critical Depth= 19.16(In.)
Pipe flow velocity= ll.22(Ft/s)
Travel time through pipe= 0.05 min.
Time of concentration (TC) = 8.48 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2012.000 to Point/Station 2012.000
**** SUBAREA FLOW ADDITION****
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Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1. 000
[COMMERCIAL area type
{General Commercial )
Impervious value, Ai = 0.850
Sub-Area C Value = 0. 820
Time of concentration= 8.48 min.
Rainfall intensity= 5.246(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.779 CA= 3.840
Subarea runoff= 0.218(CFS) for 0.090(Ac.)
Total runoff= 20.143(CFS) Total area= 4.930(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2012.000 to Point/Station 2013.000
**** PIPEFLOW TRAVEL TIME {Program estimated size) ****
Upstream point/station elevation= 311.l00{Ft.)
Downstream point/station elevation= 310.000(Ft.)
Pipe length = 96.50(Ft.) Manning's N = 0.013
No. of pipes= 1 Required pipe flow = 20.143(CFS)
Nearest computed pipe diameter 24.00(In.)
Calculated individual pipe flow = 20.143(CFS)
Normal flow depth in pipe= 16.76(In.)
Flow top width inside pipe= 22.03(In.)
Critical Depth= 19.33(In.)
Pipe flow velocity= 8.60(Ft/s)
Travel time through pipe= 0.19 min.
Time of concentration (TC) = 8.67 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2013.000 to Point/Station 2013.000
**** SUBAREA FLOW ADDITION****
Decimal fraction soil group A 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C 0.000
Decimal fraction soil group D 1.000
[COMMERCIAL area type
(General Commercial )
Impervious value, Ai = 0.850
Sub-Area C Value = 0.820
Time of concentration= 8.67 min.
Rainfall intensity= 5.173(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.781 CA= 4.110
Subarea runoff -l.119(CFS) for 0.330(Ac.)
Total runoff= 21.26l(CFS) Total area= 5.260(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2013.000 to Point/Station 2014.000
**** PIPEFLOW TRAVEL TIME (Program estimated size) ****
Upstream point/station elevation=
Downstream point/station elevation=
310.000(Ft.)
305.300(Ft.)
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Pipe length = 89.00(Ft.) Manning's N = 0.013
No. of pipes= 1 Required pipe flow = 21.261(CFS)
Nearest computed pipe diameter 18.00(In.)
Calculated individual pipe flow = 21.261(CFS)
Normal flow depth in pipe= 13.ll(In.)
Flow top width inside pipe= 16.0l(In.)
Critical depth could not be calculated.
Pipe flow velocity= 15.41(Ft/s)
Travel time through pipe= 0.10 min.
Time of concentration (TC) = 8.77 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2000.000 to Point/Station 2014.000
**** CONFLUENCE OF MAIN STREAMS****
The following data inside Main Stream is listed:
In Main Stream number: 1
Stream flow area= 5.260(Ac.)
Runoff from this stream= 21.26l(CFS)
Time of concentration= 8.77 min.
Rainfall intensity= 5.136(In/Hr)
Program is now starting with Main Stream No. 2
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2014.100 to Point/Station 2014.200
**** INITIAL AREA EVALUATION****
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C 0.000
Decimal fraction soil group D = 1. 000
[COMMERCIAL area type
(General Commercial
Impervious value, Ai = 0.850
Sub-Area C Value = 0.820
Initial subarea total flow distance 234.000{Ft.)
Highest elevation= 330.200(Ft.)
Lowest elevation= 325.000(Ft.)
Elevation difference= 5.200(Ft.) Slope= 2.222 %
INITIAL AREA TIME OF CONCENTRATION CALCULATIONS:
The maximum overland flow distance is 75.00 {Ft)
for the top area slope value of 2.22 %, in a development type of
General Commercial
In Accordance With Figure 3-3
Initial Area Time of Concentration 3.34 minutes
TC= [l.8*(1.l-C)*distance(Ft.)A.5)/(% slopeA{l/3)]
TC= [1.8*(1.1-0.8200)*{ 75.000A.5)/{ 2.222A{l/3)]= 3.34
The initial area total distance of 234.00 {Ft.) entered leaves a
remaining distance of 159.00 {Ft.)
Using Figure 3-4, the travel time for this distance is 1.68 minutes
for a distance of 159.00 {Ft.) and a slope of 2.22 %
with an elevation difference of 3.53(Ft.) from the end of the top area
Tt = [ll.9*length(Mi)A3)/{elevation change{Ft.) )]A.385 *60(min/hr)
= 1.676 Minutes
Tt=[(ll.9*0.0301A3)/{ 3.53)]A.385= 1.68
Total initial area Ti 3.34 minutes from Figure 3-3 formula plus
1.68 minutes from the Figure 3-4 formula= 5.02 minutes
Rainfall intensity (I) = 7.358(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for area {Q=KCIA) is C = 0.820
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Subarea runoff= 1.931(CFS)
Total initial stream area= 0.320(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2014.200 to Point/Station 2014.300
**** PIPEFLOW TRAVEL TIME (Program estimated size) ****
Upstream point/station elevation= 320.000(Ft.)
Downstream point/station elevation= 316.500(Ft.)
Pipe length = 29.00(Ft.) Manning's N = 0.011
No. of pipes= 1 Required pipe flow 1.931(CFS)
Nearest computed pipe diameter = 6.00(In.)
Calculated individual pipe flow = l.931(CFS)
Normal flow depth in pipe= 4.20(In.)
Flow top width inside pipe= 5.50(In.)
Critical depth could not be calculated.
Pipe flow velocity= 13.14(Ft/s)
Travel time through pipe= 0.04 min.
Time of concentration (TC) = 5.06 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2014.300 to Point/Station 2014.300
**** SUBAREA FLOW ADDITION****
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[COMMERCIAL area type
(General Commercial )
Impervious value, Ai = 0.850
Sub-Area C Value = 0.820
Time of concentration= 5.06 min.
Rainfall intensity= 7.323(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.820 CA= 0.279
Subarea runoff= 0.lll(CFS) for 0.020(Ac.)
Total runoff= 2.042(CFS) Total area= 0.340(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2014.300 to Point/Station 2014.400
**** PIPEFLOW TRAVEL TIME (Program estimated size) ****
Upstream point/station elevation= 316.500(Ft.)
Downstream point/station elevation 312.500(Ft.)
Pipe length 122.00(Ft.) Manning's N = 0.011
No. of pipes= 1 Required pipe flow 2.042(CFS)
Nearest computed pipe diameter = 9.00(In.)
Calculated individual pipe flow = 2.042(CFS)
Normal flow depth in pipe= 4.90(In.)
Flow top width inside pipe= 8.96(In.)
Critical Depth= 7.77(In.)
Pipe flow velocity= 8.30(Ft/s)
Travel time through pipe= 0.25 min.
Time of concentration (TC) = 5.30 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
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Process from Point/Station 2014.400 to Point/Station 2014.400
**** SUBAREA FLOW ADDITION****
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[COMMERCIAL area type
(General Commercial
Impervious value, Ai = 0.850
Sub-Area C Value = 0.820
Time of concentration= 5.30 min.
Rainfall intensity= 7.103(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.820 CA= 0.927
Subarea runoff= 4.540(CFS) for 0.790(Ac.)
Total runoff= 6.582(CFS) Total area= 1.130(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2014.400 to Point/Station 2014.000
**** PIPEFLOW TRAVEL TIME (Program estimated size) ****
Upstream point/station elevation= 312.500(Ft.)
Downstream point/station elevation= 305.J00(Ft.)
Pipe length = 15.40(Ft.) Manning's N = 0.011
No. of pipes= 1 Required pipe flow = 6.582(CFS)
Nearest computed pipe diameter = 9.00(In.)
Calculated individual pipe flow 6.582(CFS)
Normal flow depth in pipe= 4.46(In.)
Flow top width inside pipe= 9.00(In.)
Critical depth could not be calculated.
Pipe flow velocity= 30.14(Ft/s)
Travel time through pipe 0.01 min.
Time of concentration (TC) = 5.31 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2014.400 to Point/Station 2014.000
**** CONFLUENCE OF MAIN STREAMS****
The following data inside Main Stream is listed:
In Main Stream number: 2
Stream flow area= l.130(Ac.)
Runoff from this stream= 6.582(CFS)
Time of concentration= 5.31 min.
Rainfall intensity= 7.096(In/Hr)
Program is now starting with Main Stream No. 3
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2014.500 to Point/Station 2014.600
**** INITIAL AREA EVALUATION****
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D 1. 000
[COMMERCIAL area type
(General Commercial )
Impervious value, Ai = 0.850
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Sub-Area C Value= 0.820
Initial subarea total flow distance = 208.000(Ft.)
Highest elevation= 320.700(Ft.)
Lowest elevation= 318.000(Ft.)
Elevation difference= 2.700(Ft.) Slope= 1.298 %
INITIAL AREA TIME OF CONCENTRATION CALCULATIONS:
The maximum overland flow distance is 60.00 (Ft)
for the top area slope value of 1.30 %, in a development type of
General Commercial
In Accordance With Figure 3-3
Initial Area Time of Concentration= 3.58 minutes
TC= [1.8*(1.l-C)*distance(Ft.)A.5)/(% slopeA(l/3)]
TC= [1.8*(1.1-0.8200)*( 60.000A.5)/( l.298A(l/3)]= 3.58
The initial area total distance of 208.00 (Ft.) entered leaves a
remaining distance of 148.00 (Ft.)
Using Figure 3-4, the travel time for this distance is 1.95 minutes
for a distance of 148.00 (Ft.) and a slope of 1.30 %
with an elevation difference of 1.92(Ft.) from the end of the top area
Tt = [11.9*length(Mi)A3)/(elevation change(Ft.))]A.385 *60(min/hr)
= 1.950 Minutes
Tt=[(ll.9*0.0280A3)/( 1.92)]A.385= 1.95
Total initial area Ti= 3.58 minutes from Figure 3-3 formula plus
1.95 minutes from the Figure 3-4 formula= 5.53 minutes
Rainfall intensity (I) = 6.914(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for area (Q=KCIA) is C = 0.820
Subarea runoff= 3.005(CFS)
Total initial stream area= 0.530(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2014.600 to Point/Station 2014.700
**** PIPEFLOW TRAVEL TIME (Program estimated size) ****
Upstream point/station elevation= 313.700(Ft.)
Downstream point/station elevation= 306.700(Ft.)
Pipe length = 89.00(Ft.) Manning's N = 0.011
No. of pipes= 1 Required pipe flow = 3.005(CFS)
Nearest computed pipe diameter 9.00(In.)
Calculated individual pipe flow 3.005(CFS)
Normal fl ow depth in pipe = 4 . 7 5 (In.)
Flow top width inside pipe= 8.99(In.)
Critical depth could not be calculated.
Pipe flow velocity= 12.69(Ft/s)
Travel time through pipe 0.12 min.
Time of concentration (TC) = 5.65 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2014.700 to Point/Station 2014.700
**** SUBAREA FLOW ADDITION****
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C 0.000
Decimal fraction soil group D = 1. 000
[COMMERCIAL area type
(General Commercial )
Impervious value, Ai = 0.850
Sub-Area C Value = 0. 820
Time of concentration
Rainfall intensity=
5.65 min.
6.821(In/Hr) for a 100.0 year storm
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Effective runoff coefficient used for total area
{Q=KCIA) is C = 0.820 CA= 1.845
Subarea runoff= 9.580{CFS) for 1.720{Ac.)
Total runoff= 12.585{CFS) Total area= 2. 250 {Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2014.700 to Point/Station 2014.000
**** PIPEFLOW TRAVEL TIME {Program estimated size) ****
Upstream point/station elevation= 306.700{Ft.)
Downstream point/station elevation= 305.300{Ft.)
Pipe length = 222.00{Ft.) Manning's N = 0.013
No. of pipes= 1 Required pipe flow = 12.585{CFS)
Nearest computed pipe diameter = 21.00{In.)
Calculated individual pipe flow = 12.585{CFS)
Normal flow depth in pipe= 17.22{In.)
Flow top width inside pipe= 16.14(In.)
Critical Depth= 15.86{In.)
Pipe flow velocity= 5.96(Ft/s)
Travel time through pipe= 0.62 min.
Time of concentration {TC) = 6.27 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2014.700 to Point/Station 2014.000
**** CONFLUENCE OF MAIN STREAMS****
The following data inside Main Stream is listed:
In Main Stream number: 3
Stream flow area= 2.250{Ac.)
Runoff from this stream= 12.585(CFS)
Time of concentration= 6.27 min.
Rainfall intensity= 6.378{In/Hr)
Summary of stream data:
Stream Flow rate
No. (CFS)
TC
(min)
Rainfall Intensity
(In/Hr)
1 21.261
2 6.582
3 12.585
Qmax(l)
1. 000 *
0.724 *
0.805 *
Qmax{2) =
1.000 *
1.000 *
1. 000 *
Qmax{3) =
1.000 *
0.899 *
1.000 *
8.77
5.31
6.27
1. 000
1.000
1.000
0.606
1.000
0.848
0. 715
1.000
1.000
*
*
*
*
*
*
*
*
*
5.136
7.096
6.378
21. 261) +
6.582) +
12.585) +
21.261) +
6.582) +
12.585) +
21.261) +
6.582) +
12.585) +
Total of 3 main streams to confluence:
Flow rates before confluence point:
21.261 6.582 12.585
36.160
30.128
33.699
Maximum flow rates at confluence using above data:
36.160 30.128 33.699
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Area of streams before confluence:
5.260 1.130 2.250
Results of confluence:
Total flow rate= 36.160(CFS)
Time of concentration= 8.766 min.
Effective stream area after confluence = 8.640(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2014.000 to Point/Station 2014.000
**** SUBAREA FLOW ADDITION****
Decimal fraction soil group A= 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[COMMERCIAL area type
(General Commercial )
Impervious value, Ai= 0.850
Sub-Area C Value= 0.820
The area added to the existing stream causes a
a lower flow rate of Q = 35.893(CFS)
therefore the upstream flow rate of Q = 36.160(CFS) is being used
Time of concentration= 8.77 min.
Rainfall intensity= 5.136(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.797 CA= 6.989
Subarea runoff 0.000(CFS) for 0.130(Ac.)
Total runoff= 36.160(CFS) Total area= 8.770(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2014.000 to Point/Station 2015.000
**** PIPEFLOW TRAVEL TIME (Program estimated size) ****
Upstream point/station elevation= 305.300(Ft.)
Downstream point/station elevation= 284.200(Ft.)
Pipe length 48.00(Ft.) Manning's N = 0.013
No. of pipes= 1 Required pipe flow 36.160(CFS)
Nearest computed pipe diameter 15.00(In.)
Calculated individual pipe flow 36.160(CFS)
Normal flow depth in pipe= 10.57(In.)
Flow top width inside pipe= 13.69(In.)
Critical depth could not be calculated.
Pipe flow velocity= 39.14(Ft/s)
Travel time through pipe 0.02 min.
Time of concentration (TC) = 8.79 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2015.000 to Point/Station 2016.000
**** PIPEFLOW TRAVEL TIME (Program estimated size) ****
Upstream point/station elevation= 284.200(Ft.)
Downstream point/station elevation= 283.500(Ft.)
Pipe length = 39.00(Ft.) Manning's N = 0.013
No. of pipes= 1 Required pipe flow 36.160(CFS)
Nearest computed pipe diameter = 27.00(In.)
Calculated individual pipe flow = 36.160(CFS)
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Pipe length = 83.60(Ft.) Manning's N = 0.013
No. of pipes= 1 Required pipe flow = 3.856(CFS)
Nearest computed pipe diameter = 12.00(In.)
Calculated individual pipe flow = 3.856(CFS)
Normal flow depth in pipe= 8.64(In.)
Flow top width inside pipe= 10.78(In.)
Critical Depth= 10.0l(In.)
Pipe flow velocity= 6.37(Ft/s)
Travel time through pipe= 0.22 min.
Time of concentration (TC) = 7.06 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2024.000 to Point/Station 2024.000
**** SUBAREA FLOW ADDITION****
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D 1. 000
[COMMERCIAL area type
(General Commercial )
Impervious value, Ai = 0.850
Sub-Area C Value = 0.820
Time of concentration= 7.06 min.
Rainfall intensity= 5.907(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.820 CA= 0.845
Subarea runoff= 1.133(CFS) for 0.250(Ac.)
Total runoff= 4.989(CFS) Total area= 1.030(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2024.000 to Point/Station 2025.000
**** PIPEFLOW TRAVEL TIME (Program estimated size) ****
Upstream point/station elevation= 325.900(Ft.)
Downstream point/station elevation= 323.800(Ft.)
Pipe length = 80.00(Ft.) Manning's N = 0.013
No. of pipes= 1 Required pipe flow = 4.989(CFS)
Nearest computed pipe diameter = 12.00(In.)
Calculated individual pipe flow 4.989(CFS)
Normal flow depth in pipe= 8.6l(In.)
Flow top width inside pipe= 10.S0(In.)
Critical Depth= 11.00(In.)
Pipe flow velocity= 8.27(Ft/s)
Travel time through pipe= 0.16 min.
Time of concentration (TC) = 7.22 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2025.000 to Point/Station 2025.000
**** SUBAREA FLOW ADDITION****
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[COMMERCIAL area type
(General Commercial )
Impervious value, Ai = 0.850
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Sub-Area C Value= 0.820
Time of concentration= 7.22 min.
Rainfall intensity= 5.822(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.820 CA= 0.943
Subarea runoff= 0.501(CFS) for 0.120(Ac.)
Total runoff= 5.490(CFS) Total area= 1.150(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2025.000 to Point/Station 2026.000
**** PIPEFLOW TRAVEL TIME (Program estimated size) ****
Upstream point/station elevation= 323.800(Ft.)
Downstream point/station elevation= 323.200(Ft.)
Pipe length = 25.00(Ft.) Manning"s N = 0.013
No. of pipes= 1 Required pipe flow = 5.490(CFS)
Nearest computed pipe diameter = 12.00(In.)
Calculated individual pipe flow = 5.490(CFS)
Normal flow depth in pipe= 9.77(In.)
Flow top width inside pipe= 9.33(In.)
Critical Depth= 11.26(In.)
Pipe flow velocity= 8.0l(Ft/s)
Travel time through pipe= 0.05 min.
Time of concentration (TC) = 7.27 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2026.000 to Point/Station 2026.000
**** SUBAREA FLOW ADDITION****
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C 0.000
Decimal fraction soil group D = 1.000
[COMMERCIAL area type
(General Commercial
Impervious value, Ai = 0.850
Sub-Area C Value = 0. 820
Time of concentration= 7.27 min.
Rainfall intensity= 5.795(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area
{Q=KCIA) is C = 0.820 CA= 1.689
Subarea runoff 4.299(CFS) for 0.910(Ac.)
Total runoff= 9.789(CFS) Total area= 2.060(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2026.000 to Point/Station 2027.000
**** PIPEFLOW TRAVEL TIME (Program estimated size) ****
Upstream point/station elevation= 323.200(Ft.)
Downstream point/station elevation= 322.700(Ft.)
Pipe length = 17.80(Ft.) Manning's N = 0.013
No. of pipes= 1 Required pipe flow = 9.789(CFS)
Nearest computed pipe diameter = 15.00(In.)
Calculated individual pipe flow = 9.789(CFS)
Normal flow depth in pipe= ll.17(In.)
Flow top width inside pipe= 13.08(In.)
Critical Depth= 14.14(In.)
Pipe flow velocity= 9.99(Ft/s)
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Travel time through pipe=
Time of concentration {TC) =
0.03 min.
7.30 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2020.000 to Point/Station 2027.000
**** CONFLUENCE OF MINOR STREAMS****
Along Main Stream number: 2 in normal stream number 1
Stream flow area= 2.060{Ac.)
Runoff from this stream= 9.789{CFS)
Time of concentration= 7.30 min.
Rainfall intensity= 5.780{In/Hr)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2027.100 to Point/Station 2027.200
**** INITIAL AREA EVALUATION****
Decimal fraction soil group A = 0.000
Decimal fraction soil group B 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[COMMERCIAL area type
(General Commercial )
Impervious value, Ai = 0.850
Sub-Area C Value = 0.820
Initial subarea total flow distance = 175.000{Ft.)
Highest elevation= 338.000(Ft.)
Lowest elevation= 334.000{Ft.)
Elevation difference 4.000{Ft.) Slope= 2.286 %
INITIAL AREA TIME OF CONCENTRATION CALCULATIONS:
The maximum overland flow distance is 75.00 (Ft)
for the top area slope value of 2.29 %, in a development type of
General Commercial
In Accordance With Figure 3-3
Initial Area Time of Concentration 3.31 minutes
TC= [1.8*{1.l-C)*distance{Ft.)A.5)/(% slopeA{l/3)]
TC= [1.8*(1.1-0.8200)*{ 75.000A.5)/{ 2.286A{l/3)]= 3.31
The initial area total distance of 175.00 {Ft.) entered leaves a
remaining distance of 100.00 (Ft.)
Using Figure 3-4, the travel time for this distance is 1.16 minutes
for a distance of 100.00 (Ft.) and a slope of 2.29 %
with an elevation difference of 2.29(Ft.) from the end of the top area
Tt = [ll.9*length{Mi)A3)/{elevation change(Ft.))]A.385 *60(min/hr)
= 1.160 Minutes
Tt=[{ll.9*0.0189A3)/{ 2.29)]A.385= 1.16
Total initial area Ti 3.31 minutes from Figure 3-3 formula plus
1.16 minutes from the Figure 3-4 formula= 4.47 minutes
Calculated TC of 4.473 minutes is less than 5 minutes,
resetting TC to 5.0 minutes for rainfall intensity calculations
Rainfall intensity {I) = 7.377{In/Hr) for a 100.0 year storm
Effective runoff coefficient used for area (Q=KCIA) is C = 0.820
Subarea runoff= l.512{CFS)
Total initial stream area= 0.250{Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2027.200 to Point/Station 2027.300
**** PIPEFLOW TRAVEL TIME {Program estimated size) ****
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Upstream point/station elevation= 331.300(Ft.)
Downstream point/station elevation= 326.600(Ft.)
Pipe length = 115.00(Ft.) Manning's N = 0.011
No. of pipes= 1 Required pipe flow = 1.512(CFS)
Nearest computed pipe diameter = 9.00(In.)
Calculated individual pipe flow = 1.512(CFS)
Normal flow depth in pipe= 3.86(In.)
Flow top width inside pipe= 8.91(In.)
Critical Depth= 6.80(In.)
Pipe flow velocity= 8.35(Ft/s)
Travel time through pipe= 0.23 min.
Time of concentration (TC) = 4.70 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2027.300 to Point/Station 2027.300
**** SUBAREA FLOW ADDITION****
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1. 000
[COMMERCIAL area type
(General Commercial )
Impervious value, Ai = 0.850
Sub-Area C Value = 0.820
Time of concentration= 4.70 min.
Rainfall intensity= 7.377(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.820 CA= 0.476
Subarea runoff l.996(CFS) for 0.330(Ac.)
Total runoff= 3.509(CFS) Total area= 0.580(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2027.300 to Point/Station 2027.400
**** PIPEFLOW TRAVEL TIME (Program estimated size) ****
Upstream point/station elevation= 326.600(Ft.)
Downstream point/station elevation 323.600(Ft.)
Pipe length = 74.00(Ft.) Manning's N = 0.011
No. of pipes= 1 Required pipe flow = 3.509(CFS)
Nearest computed pipe diameter 9.00(In.)
Calculated individual pipe flow = 3.509(CFS)
Normal flow depth in pipe= 6.62(In.)
Flow top width inside pipe= 7.94(In.)
Critical depth could not be calculated.
Pipe flow velocity= 10.07(Ft/s)
Travel time through pipe 0.12 min.
Time of concentration (TC) = 4.83 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2027.400 to Point/Station 2027.400
**** SUBAREA FLOW ADDITION****
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[COMMERCIAL area type
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{General Commercial )
Impervious value, Ai= 0.850
Sub-Area C Value= 0.820
Time of concentration= 4.83 min.
Rainfall intensity= 7.377(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area
{Q=KCIA) is C = 0.820 CA= 0.730
Subarea runoff= 1.875{CFS) for 0.310(Ac.)
Total runoff= 5.384(CFS) Total area= 0.890{Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2027.400 to Point/Station 2027.000
**** PIPEFLOW TRAVEL TIME {Program estimated size) ****
Upstream point/station elevation= 323.600(Ft.)
Downstream point/station elevation= 322.700(Ft.)
Pipe length = 20.60{Ft.) Manning's N = 0.011
No. of pipes= 1 Required pipe flow = 5.384{CFS)
Nearest computed pipe diameter = 12.00(In.)
Calculated individual pipe flow = 5.384{CFS)
Normal flow depth in pipe= 6.79(In.)
Flow top width inside pipe= 11.90(In.)
Critical Depth= ll.22(In.)
Pipe flow velocity= 11.77{Ft/s)
Travel time through pipe= 0.03 min.
Time of concentration (TC) = 4.85 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2027.400 to Point/Station 2027.000
**** CONFLUENCE OF MINOR STREAMS****
Along Main Stream number: 2 in normal stream number 2
Stream flow area= 0.890(Ac.)
Runoff from this stream 5.384(CFS)
Time of concentration= 4.85 min.
Rainfall intensity= 7.377(In/Hr)
Summary of stream data:
Stream Flow rate TC Rainfall Intensity
No. {CFS) (min) (In/Hr)
1 9.789 7.30 5.780
2 5.384 4.85 7.377
Qmax{l) =
1.000 * 1.000 * 9.789) +
0.783 * 1. 000 * 5.384) + = 14.006
Qmax{2)
1. 000 * 0.665 * 9.789) +
1. 000 * 1.000 * 5.384) + = 11. 893
Total of 2 streams to confluence:
Flow rates before confluence point:
9.789 5.384
Maximum flow rates at confluence using above data:
14.006 11.893
Area of streams before confluence:
2.060 0.890
Results of confluence:
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Total flow rate= 14.006(CFS)
Time of concentration= 7.300 min.
Effective stream area after confluence= 2.950(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2027.000 to Point/Station 2027.000
**** SUBAREA FLOW ADDITION****
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[COMMERCIAL area type
(General Commercial )
Impervious value, Ai = 0.850
Sub-Area C Value = 0.820
Time of concentration= 7.30 min.
Rainfall intensity= 5.780(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.820 CA= 2.780
Subarea runoff= 2.060(CFS) for 0.440(Ac.)
Total runoff= 16.066(CFS) Total area= 3.390(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2027.000 to Point/Station 2028.000
**** PIPEFLOW TRAVEL TIME (Program estimated size) ****
Upstream point/station elevation= 322.400(Ft.}
Downstream point/station elevation= 316.600(Ft.}
Pipe length = 150.00(Ft.) Manning's N = 0.013
No. of pipes= 1 Required pipe flow = 16.066(CFS)
Nearest computed pipe diameter = 18.00(In.)
Calculated individual pipe flow = 16.066(CFS}
Normal flow depth in pipe= 11.93(In.)
Flow top width inside pipe= 17.02(In.)
Critical depth could not be calculated.
Pipe flow velocity= 12.92(Ft/s)
Travel time through pipe= 0.19 min.
Time of concentration (TC) = 7.49 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2028.000 to Point/Station 2028.000
**** SUBAREA FLOW ADDITION****
Decimal fraction soil group A
Decimal fraction soil group B
Decimal fraction soil group C =
Decimal fraction soil group D =
[COMMERCIAL area type
(General Commercial )
Impervious value, Ai= 0.850
Sub-Area C Value= 0.820
0.000
0.000
0.000
1.000
Time of concentration= 7.49 min.
Rainfall intensity= 5.683(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.820 CA= 3.132
Subarea runoff= 1.735(CFS) for 0.430(Ac.)
Total runoff= 17.801(CFS) Total area= 3.820(Ac.)
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++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2028.000 to Point/Station 2029.000
**** PIPEFLOW TRAVEL TIME (Program estimated size) ****
Upstream point/station elevation= 316.300(Ft.)
Downstream point/station elevation= 315.200(Ft.)
Pipe length = 54.00(Ft.) Manning's N = 0.013
No. of pipes= 1 Required pipe flow = 17.80l(CFS)
Nearest computed pipe diameter = 21.00(In.)
Calculated individual pipe flow 17.B0l(CFS)
Normal flow depth in pipe= 14.04(In.)
Flow top width inside pipe= 19.77(In.)
Critical Depth= 18.46(In.)
Pipe flow velocity= 10.41(Ft/s)
Travel time through pipe= 0.09 min.
Time of concentration (TC) = 7.58 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2029.000 to Point/Station 2029.000
**** SUBAREA FLOW ADDITION****
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C 0.000
Decimal fraction soil group D = 1.000
[COMMERCIAL area type
(General Commercial )
Impervious value, Ai = 0.850
Sub-Area C Value = 0.820
Time of concentration= 7.58 min.
Rainfall intensity= 5.641(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.820 CA= 3.190
Subarea runoff= 0.193(CFS) for 0.070(Ac.)
Total runoff= 17.994(CFS) Total area= 3.890(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2029.000 to Point/Station 2030.000
**** PIPEFLOW TRAVEL TIME (Program estimated size) ****
Upstream point/station elevation= 315.200(Ft.)
Downstream point/station elevation= 313.900(Ft.)
Pipe length = 67.50(Ft.) Manning's N = 0.013
No. of pipes= 1 Required pipe flow = 17.994(CFS)
Nearest computed pipe diameter 21.00(In.)
Calculated individual pipe flow = 17.994(CFS)
Normal flow depth in pipe= 14.44(In.)
Flow top width inside pipe= 19.47(In.)
Critical Depth= 18.52(In.)
Pipe flow velocity= 10.20(Ft/s)
Travel time through pipe= 0.11 min.
Time of concentration (TC) = 7.69 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2030.000 to Point/Station 2030.000
**** SUBAREA FLOW ADDITION****
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Elevation difference= 6.500(Ft.) Slope= 2.731 %
INITIAL AREA TIME OF CONCENTRATION CALCULATIONS:
The maximum overland flow distance is 85.00 (Ft)
for the top area slope value of 2.73 %, in a development type of
General Commercial
In Accordance With Figure 3-3
Initial Area Time of Concentration= 3.32 minutes
TC= [1.8*(1.l-C)*distance(Ft.)A.5)/(% slopeA(l/3)]
TC= [1.8*(1.1-0.8200)*( 85.000A.5)/( 2.731A(l/3)]= 3.32
The initial area total distance of 238.00 (Ft.) entered leaves a
remaining distance of 153.00 (Ft.)
Using Figure 3-4, the travel time for this distance is 1.50 minutes
for a distance of 153.00 (Ft.) and a slope of 2.73 %
with an elevation difference of 4.18(Ft.) from the end of the top area
Tt = [11.9*length(Mi)A3)/(elevation change(Ft.))JA.385 *60(min/hr)
= 1.503 Minutes
Tt=[(ll.9*0.0290A3)/( 4.18)]A_385= 1.50
Total initial area Ti= 3.32 minutes from Figure 3-3 formula plus
1.50 minutes from the Figure 3-4 formula= 4.83 minutes
Calculated TC of 4.827 minutes is less than 5 minutes,
resetting TC to 5.0 minutes for rainfall intensity calculations
Rainfall intensity (I) = 7.377(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for area (Q=KCIA) is C = 0.820
Subarea runoff= 1.573(CFS)
Total initial stream area= 0.260(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2031.200 to Point/Station 2031.300
**** PIPEFLOW TRAVEL TIME (Program estimated size) ****
Upstream point/station elevation= 324.500(Ft.)
Downstream point/station elevation= 320.300(Ft.)
Pipe length 85.00(Ft.) Manning's N = 0.011
No. of pipes= 1 Required pipe flow 1.573(CFS)
Nearest computed pipe diameter = 9.00(In.)
Calculated individual pipe flow 1.573(CFS)
Normal flow depth in pipe= 3.74(In.)
Flow top width inside pipe= 8.87(In.)
Critical Depth= 6.93(In.)
Pipe flow velocity= 9.05(Ft/s)
Travel time through pipe= 0.16 min.
Time of concentration (TC) = 4.98 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2031.300 to Point/Station 2031.300
**** SUBAREA FLOW ADDITION****
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1. 000
[COMMERCIAL area type
(General Commercial )
Impervious value, Ai = 0.850
Sub-Area C Value = 0.820
Time of concentration= 4.98 min.
Rainfall intensity= 7.377(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.820 CA= 0.418
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Subarea runoff=
Total runoff=
1.512(CFS) for 0.250(Ac.)
3.085(CFS) Total area= 0.510(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2031.300 to Point/Station 2031.400
**** PIPEFLOW TRAVEL TIME (Program estimated size) ****
Upstream point/station elevation= 320.300(Ft.)
Downstream point/station elevation= 316.900(Ft.)
Pipe length = 65.00(Ft.) Manning's N = 0.011
No. of pipes= 1 Required pipe flow 3.085(CFS)
Nearest computed pipe diameter = 9.00(In.)
Calculated individual pipe flow = 3.085(CFS)
Normal flow depth in pipe= 5.50(In.)
Flow top width inside pipe= 8.78(In.)
Critical depth could not be calculated.
Pipe flow velocity= 10.92(Ft/s)
Travel time through pipe= 0.10 min.
Time of concentration (TC) = 5.08 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2031.400 to Point/Station 2031.400
**** SUBAREA FLOW ADDITION****
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C 0.000
Decimal fraction soil group D = 1.000
[COMMERCIAL area type
(General Commercial )
Impervious value, Ai = 0.850
Sub-Area C Value = 0.820
Time of concentration= 5.08 min.
Rainfall intensity= 7.300(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.820 CA= 0.697
Subarea runoff 2.003(CFS) for 0.340(Ac.)
Total runoff= 5.088(CFS) Total area= 0.850(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2031.400 to Point/Station 2031.700
**** PIPEFLOW TRAVEL TIME (Program estimated size) ****
Upstream point/station elevation= 317.500(Ft.)
Downstream point/station elevation 314.300(Ft.)
Pipe length 61.50(Ft.) Manning's N = 0.011
No. of pipes= 1 Required pipe flow 5.088(CFS)
Nearest computed pipe diameter 12.00(In.)
Calculated individual pipe flow = 5.088(CFS)
Normal flow depth in pipe= 6.21(In.)
Flow top width inside pipe= 11.99(In.)
Critical Depth= ll.05(In.)
Pipe flow velocity= 12.41(Ft/s)
Travel time through pipe= 0.08 min.
Time of concentration (TC) = 5.17 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
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Process from Point/Station 2031.700 to Point/Station
**** SUBAREA FLOW ADDITION****
Decimal fraction soil
Decimal fraction soil
Decimal fraction soil
Decimal fraction soil
[COMMERCIAL area type
group
group
group
group
(General Commercial )
Impervious value, Ai= 0.850
Sub-Area C Value= 0.820
A =
B =
C =
D =
0.000
0.000
0.000
1.000
Time of concentration= 5.17 min.
2031.700
Rainfall intensity= 7.224(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.820 CA= 1.214
Subarea runoff= 3.679(CFS) for 0.630(Ac.)
Total runoff= 8.767(CFS) Total area= 1.480(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2031.700 to Point/Station 2031.000
**** PIPEFLOW TRAVEL TIME (Program estimated size) ****
Upstream point/station elevation= 314.300(Ft.)
Downstream point/station elevation= 313.700(Ft.)
Pipe length 11.00(Ft.) Manning's N = 0.011
No. of pipes= 1 Required pipe flow 8.767(CFS)
Nearest computed pipe diameter 12.00(In.)
Calculated individual pipe flow = 8.767(CFS)
Normal flow depth in pipe= 8.84(In.)
Flow top width inside pipe= 10.57(In.)
Critical depth could not be calculated.
Pipe flow velocity= 14.15(Ft/s)
Travel time through pipe= 0.01 min.
Time of concentration (TC) = 5.18 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2031.700 to Point/Station 2031.000
**** CONFLUENCE OF MINOR STREAMS****
Along Main Stream number: 2 in normal stream number 2
Stream flow area= l.480(Ac.)
Runoff from this stream 8.767(CFS)
Time of concentration= 5.18 min.
Rainfall intensity= 7.212(In/Hr)
Summary of stream data:
Stream Flow rate TC Rainfall Intensity
No. (CFS) (min) (In/Hr)
1 19.110 7.71 5.581
2 8.767 5.18 7.212
Qmax(l) =
1.000 * 1.000 * 19.110) +
0.774 * 1.000 * 8.767) + = 25.894
Qmax(2)
1.000 * 0.672 * 19.110) +
1.000 * 1.000 * 8.767) + = 21.608
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Total of 2 streams to confluence:
Flow rates before confluence point:
19.110 8.767
Maximum flow rates at confluence using above data:
25.894 21.608
Area of streams before confluence:
4.170 1.480
Results of confluence:
Total flow rate= 25.894(CFS)
Time of concentration= 7.706 min.
Effective stream area after confluence 5. 650 (Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2031.000 to Point/Station 2032.000
**** PIPEFLOW TRAVEL TIME (Program estimated size) ****
Upstream point/station elevation= 313.300(Ft.)
Downstream point/station elevation= 287.600(Ft.)
Pipe length = 347.00(Ft.) Manning's N = 0.013
No. of pipes= 1 Required pipe flow = 25.894(CFS)
Nearest computed pipe diameter = 18.00(In.)
Calculated individual pipe flow = 25.894(CFS)
Normal flow depth in pipe= 13.43(In.)
Flow top width inside pipe= 15.67(In.)
Critical depth could not be calculated.
Pipe flow velocity= 18.32(Ft/s)
Travel time through pipe 0.32 min.
Time of concentration (TC) = 8.02 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2032.000 to Point/Station 2016.000
**** PIPEFLOW TRAVEL TIME (Program estimated size) ****
Upstream point/station elevation= 287.200(Ft.)
Downstream point/station elevation= 283.400(Ft.)
Pipe length = 68.00(Ft.) Manning's N = 0.013
No. of pipes= 1 Required pipe flow = 25.894(CFS)
Nearest computed pipe diameter. = 21.00(In.)
Calculated individual pipe flow 25.894(CFS)
Normal flow depth in pipe= 12.84(In.)
Flow top width inside pipe= 20.47{In.)
Critical depth could not be calculated.
Pipe flow velocity= 16.81(Ft/s)
Travel time through pipe= 0.07 min.
Time of concentration (TC) = 8.09 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2032.000 to Point/Station 2016.000
**** CONFLUENCE OF MAIN STREAMS****
The following data inside Main Stream is listed:
In Main Stream number: 2
Stream flow area= 5.650(Ac.)
Runoff from this stream= 25.894(CFS)
Time of concentration= 8.09 min.
Rainfall intensity= 5.409(In/Hr)
Summary of stream data:
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Stream Flow rate TC Rainfall Intensity
No. (CFS) (min) (In/Hr)
1 36.160 8.84 5.107
2 25.894 8.09 5.409
Qmax(l)
1.000 * 1.000 * 36.160) +
0.944 * 1.000 * 25.894) + = 60.610
Qmax(2) =
1.000 * 0.915 * 36.160) +
1.000 * 1.000 * 25.894) + = 58.975
Total of 2 main streams to confluence:
Flow rates before confluence point:
36.160 25.894
Maximum flow rates at confluence using above data:
60.610 58.975
Area of streams before confluence:
8.770 5.650
Results of confluence:
Total flow rate= 60.610(CFS)
Time of concentration= 8.842 min.
Effective stream area after confluence 14.420(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2016.000 to Point/Station 2016.000
**** SUBAREA FLOW ADDITION****
Decimal fraction soil group A=
Decimal fraction soil group B =
Decimal fraction soil group C
Decimal fraction soil group D
[COMMERCIAL area type
(General Commercial )
Impervious value, Ai= 0.850
Sub-Area C Value= 0.820
0.000
0.000
0.000
1.000
Time of concentration= 8.84 min.
Rainfall intensity= 5.107(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.807 CA= 12.466
Subarea runoff 3.06l(CFS) for l.030(Ac.)
Total runoff= 63.671(CFS) Total area= 15.450(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2016.000 to Point/Station 2065.000
**** PIPEFLOW TRAVEL TIME (Program estimated size) ****
Upstream point/station elevation= 283.400(Ft.)
Downstream point/station elevation= 272.700(Ft.)
Pipe length = 120.00(Ft.) Manning's N = 0.013
No. of pipes= 1 Required pipe flow 63.671(CFS)
Nearest computed pipe diameter = 24.00(In.)
Calculated individual pipe flow = 63.671(CFS)
Normal flow depth in pipe= 18.54(In.)
Flow top width inside pipe= 20.12(In.)
Critical depth could not be calculated.
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Qmax(l) =
1.000 * 1.000 * 2.946) +
1.000 * 0.414 * 32.500) + = 16.417
Qmax(2)
0.567 * 1.000 * 2.946) +
1. 000 * 1.000 * 32.500) + = 34.169
Total of 2 streams to confluence:
Flow rates before confluence point:
2.946 32.500
Maximum flow rates at confluence using above data:
16.417 34.169
Area of streams before confluence:
0.600 10.800
Results of confluence:
Total flow rate= 34.169(CFS)
Time of concentration= 17.000 min.
Effective stream area after confluence= 11. 400 (Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2062.000 to Point/Station 2063.000
**** PIPEFLOW TRAVEL TIME (Program estimated size) ****
Upstream point/station elevation= 306.S00(Ft.)
Downstream point/station elevation= 300.300(Ft.)
Pipe length 57.00(Ft.) Manning"s N = 0.013
No. of pipes= 1 Required pipe flow = 34.169(CFS)
Nearest computed pipe diameter = 18.00(In.)
Calculated individual pipe flow 34.169(CFS)
Normal flow depth in pipe= 14.20(In.)
Flow top width inside pipe= 14.69(In.)
Critical depth could not be calculated.
Pipe flow velocity= 22.86(Ft/s)
Travel time through pipe= 0.04 min.
Time of concentration (TC) = 17.04 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2063.000 to Point/Station 2064.000
**** PIPEFLOW TRAVEL TIME (Program estimated size) ****
Upstream point/station elevation= 300.000(Ft.)
Downstream point/station elevation 286.000(Ft.)
Pipe length 229.00(Ft.) Manning's N = 0.013
No. of pipes= 1 Required pipe flow 34.169(CFS)
Nearest computed pipe diameter 21.00(In.)
Calculated individual pipe flow 34.169(CFS)
Normal flow depth in pipe= 15.19(In.)
Flow top width inside pipe= 18.79(In.)
Critical depth could not be calculated.
Pipe flow velocity= 18.36(Ft/s)
Travel time through pipe= 0.21 min.
Time of concentration (TC) = 17.25 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2064.000 to Point/Station 2065.000
**** PIPEFLOW TRAVEL TIME (Program estimated size) ****
Upstream point/station elevation= 285.700(Ft.)
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Downstream point/station elevation= 272.700(Ft.)
Pipe length = 230.00(Ft.) Manning's N = 0.013
No. of pipes= 1 Required pipe flow = 34.169{CFS)
Nearest computed pipe diameter 21.00{In.)
Calculated individual pipe flow = 34.169{CFS)
Normal flow depth in pipe= 15.68{In.)
Flow top width inside pipe= 18.27(In.)
Critical depth could not be calculated.
Pipe flow velocity= 17.74(Ft/s)
Travel time through pipe 0.22 min.
Time of concentration (TC) = 17.47 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2064.000 to Point/Station 2065.000
**** CONFLUENCE OF MAIN STREAMS****
The following data inside Main Stream is listed:
In Main Stream number: 2
Stream flow area= ll.400{Ac.)
Runoff from this stream= 34.169(CFS)
Time of concentration= 17.47 min.
Rainfall intensity= 3.292{In/Hr)
Summary of stream data:
Stream Flow rate TC Rainfall Intensity
No. (CFS) {min) (In/Hr)
1 63.671 8.92 5.077
2 34.169 17.47 3.292
Qmax{l) =
1.000 * 1.000 * 63.671) +
1.000 * 0.511 * 34.169) + 81.129
Qmax(2) =
0.648 * 1.000 * 63.671) +
1.000 * 1.000 * 34.169) + = 75.458
Total of 2 main streams to confluence:
Flow rates before confluence point:
63.671 34.169
Maximum flow rates at confluence using above data:
81.129 75.458
Area of streams before confluence:
15.450 11.400
Results of confluence:
Total flow rate= 81.129(CFS)
Time of concentration= 8.924 min.
Effective stream area after confluence 26.850(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2065.000 to Point/Station 2066.000
**** PIPEFLOW TRAVEL TIME (Program estimated size) ****
Upstream point/station elevation= 272.300(Ft.)
Downstream point/station elevation 268.l00(Ft.)
Pipe length = 206.00(Ft.) Manning's N = 0.013
No. of pipes= 1 Required pipe flow 81.129(CFS)
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Nearest computed pipe diameter = 36.00(In.)
Calculated individual pipe flow = 81.129(CFS)
Normal flow depth in pipe= 25.55(In.)
Flow top width inside pipe= 32.68(In.)
Critical Depth= 33.37(In.)
Pipe flow velocity= 15.13(Ft/s)
Travel time through pipe= 0.23 min.
Time of concentration (TC) = 9.15 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2066.000 to Point/Station 2067.000
**** PIPEFLOW TRAVEL TIME (Program estimated size) ****
Upstream point/station elevation= 267.700(Ft.)
Downstream point/station elevation= 267.000(Ft.)
Pipe length = 61.00(Ft.) Manning's N = 0.013
No. of pipes= 1 Required pipe flow = 81.129(CFS)
Nearest computed pipe diameter = 39.00(In.)
Calculated individual pipe flow 81.129(CFS)
Normal flow depth in pipe= 29.39(In.)
Flow top width inside pipe= 33.61(In.)
Critical Depth= 33.88(In.)
Pipe flow velocity= 12.09(Ft/s)
Travel time through pipe= 0.08 min.
Time of concentration (TC) = 9.23 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2000.000 to Point/Station 2067.000
**** CONFLUENCE OF MAIN STREAMS****
The following data inside Main Stream is listed:
In Main Stream number: 1
Stream flow area= 26.850(Ac.)
Runoff from this stream 81.129(CFS)
Time of concentration= 9.23 min.
Rainfall intensity= 4.966(In/Hr)
Program is now starting with Main Stream No. 2
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2067.000 to Point/Station 2067.000
**** USER DEFINED FLOW INFORMATION AT A POINT****
Decimal fraction soil group A=
Decimal fraction soil group B =
Decimal fraction soil group C
Decimal fraction soil group D =
[COMMERCIAL area type
(General Commercial )
Impervious value, Ai= 0.850
Sub-Area C Value= 0.820
0.000
0.000
0.000
1.000
Rainfall intensity (I) = 4.968(In/Hr) for a
User specified values are as follows:
100.0 year storm
TC= 9.23 min. Rain intensity= 4.97(In/Hr)
Total area= 0.770(Ac.) Total runoff= 3.250(CFS)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2067.000 to Point/Station 2067.000
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**** CONFLUENCE OF MAIN STREAMS****
The following data inside Main Stream is listed:
In Main Stream nwnber: 2
Stream flow area= 0.770(Ac.)
Runoff from this stream= 3.250(CFS)
Time of concentration= 9.23 min.
Rainfall intensity= 4.968(In/Hr)
Summary of stream data:
Stream Flow rate TC Rainfall Intensity
No. (CFS) (min) (In/Hr)
1 81.129 9.23 4.966
2 3.250 9.23 4.968
Qmax ( 1) =
1.000 * 1. 000 * 81.129) +
1. 000 * 1. 000 * 3.250) + = 84.378
Qmax(2) =
1. 000 * 0.999 * 81.129) +
1. 000 * 1.000 * 3.250) + = 84.338
Total of 2 main streams to confluence:
Flow rates before confluence point:
81.129 3.250
Maximum flow rates at confluence using above data:
84.378 84.338
Area of streams before confluence:
26.850 0.770
Results of confluence:
Total flow rate= 84.378(CFS)
Time of concentration= 9.235 min.
Effective stream area after confluence = 2 7 . 6 2 0 ( Ac . )
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2067.000 to Point/Station 2068.000
**** PIPEFLOW TRAVEL TIME (Program estimated size) ****
Upstream point/station elevation= 267.000(Ft.)
Downstream point/station elevation= 266.lOO(Ft.)
Pipe length = 77.00(Ft.) Manning's N = 0.013
No. of pipes= 1 Required pipe flow = 84.378(CFS)
Nearest computed pipe diameter = 39.00(In.)
Calculated individual pipe flow = 84.378(CFS)
Normal flow depth in pipe= 30.19(In.)
Flow top width inside pipe= 32.62(In.)
Critical Depth= 34.40(In.)
Pipe flow velocity= 12.24(Ft/s)
Travel time through pipe= 0.10 min.
Time of concentration (TC) = 9.34 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2000.000 to Point/Station 2068.000
**** CONFLUENCE OF MAIN STREAMS****
The following data inside Main Stream is listed:
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In Main Stream number: 1
Stream flow area= 27.620(Ac.)
Runoff from this stream= 84.378(CFS)
Time of concentration= 9.34 min.
Rainfall intensity= 4.930(In/Hr)
Program is now starting with Main Stream No. 2
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2040.000 to Point/Station 2041.000
**** INITIAL AREA EVALUATION****
Decimal fraction soil group A= 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[COMMERCIAL area type
(General Commercial )
Impervious value, Ai= 0.850
Sub-Area C Value= 0.820
Initial subarea total flow distance = 770.000(Ft.)
Highest elevation= 340.000(Ft.)
Lowest elevation= 322.000(Ft.)
Elevation difference= 18.000(Ft.) Slope= 2.338 %
INITIAL AREA TIME OF CONCENTRATION CALCULATIONS:
The maximum overland flow distance is 75.00 (Ft)
for the top area slope value of 2.34 %, in a development type of
General Commercial
In Accordance With Figure 3-3
Initial Area Time of Concentration 3.29 minutes
TC= [1.8*(1.l-C)*distance(Ft.)A.5)/(% slopeA(l/3))
TC= [1.8*(1.1-0.8200)*( 75.000A.5)/( 2.338A(l/3))= 3.29
The initial area total distance of 770.00 (Ft.) entered leaves a
remaining distance of 695.00 (Ft.)
Using Figure 3-4, tne travel time for this distance is 5.12 minutes
for a distance of 695.00 (Ft.) and a slope of 2.34 %
with an elevation difference of 16.25(Ft.) from the end of the top area
Tt = [ll.9*length(Mi)A3)/(elevation change(Ft.))]A.385 *60(min/hr)
5.116 Minutes
Tt=[(ll.9*0.1316A3)/( 16.25)}A.385= 5.12
Total initial area Ti= 3.29 minutes from Figure 3-3 formula plus
5.12 minutes from the Figure 3-4 formula= 8.40 minutes
Rainfall intensity (I) = 5.277(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for area (Q=KCIA) is C = 0.820
Subarea runoff= 10.732(CFS)
Total initial stream area= 2.480(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2041.000 to Point/Station 2042.000
**** PIPEFLOW TRAVEL TIME (Program estimated size) ****
Upstream point/station elevation= 318.000(Ft.)
Downstream point/station elevation= 290.000(Ft.)
Pipe length = 196.00(Ft.) Manning's N = 0.013
No. of pipes= 1 Required pipe flow = 10.732(CFS)
Nearest computed pipe diameter 12.00(In.)
Calculated individual pipe flow = 10.732(CFS)
Normal flow depth in pipe= 8.l0(In.)
Flow top width inside pipe= 11.24(In.)
Critical depth could not be calculated.
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Pipe flow velocity= 19.04(Ft/s)
Travel time through pipe= 0.17 min.
Time of concentration (TC) = 8.58 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2042.000 to Point/Station 2042.000
**** SUBAREA FLOW ADDITION****
Decimal fraction soil group A= 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[COMMERCIAL area type
(General Commercial )
Impervious value, Ai= 0.850
Sub-Area C Value= 0.820
Time of concentration= 8.58 min.
Rainfall intensity= 5.209(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.820 CA= 3.600
Subarea runoff= 8.019(CFS) for 1.910(Ac.)
Total runoff= 18.752(CFS) Total area= 4.390(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2042.000 to Point/Station 2068.000
**** PIPEFLOW TRAVEL TIME (Program estimated size) ****
Upstream point/station elevation= 290.000(Ft.)
Downstream point/station elevation= 266.000(Ft.)
Pipe length = 76.70(Ft.) Manning's N = 0.013
No. of pipes= 1 Required pipe flow 18.752(CFS)
Nearest computed pipe diameter = 12.00(In.)
Calculated individual pipe flow 18.752(CFS)
Normal flow depth in pipe= 9.26(In.)
Flow top width inside pipe= 10.0B(In.)
Critical depth could not be calculated.
Pipe flow velocity= 28.85(Ft/s)
Travel time through pipe= 0.04 min.
Time of concentration (TC) = 8.62 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2042.000 to Point/Station 2068.000
**** CONFLUENCE OF MAIN STREAMS****
The following data inside Main Stream is listed:
In Main Stream number: 2
Stream flow area= 4.390(Ac.)
Runoff from this stream 18.752(CFS)
Time of concentration= 8.62 min.
Rainfall intensity= 5.192(In/Hr)
Program is now starting with Main Stream No. 3
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2049.000 to Point/Station 2050.000
**** INITIAL AREA EVALUATION****
Decimal fraction soil group A= 0.000
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Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[COMMERCIAL area type
(General Commercial )
Impervious value, Ai= 0.850
Sub-Area C Value= 0.820
Initial subarea total flow distance = 36.000(Ft.)
Highest elevation= 338.000(Ft.)
Lowest elevation= 320.000(Ft.)
Elevation difference= 18.000(Ft.) Slope= 50.000 %
Top of Initial Area Slope adjusted by User to 0.010 %
INITIAL AREA TIME OF CONCENTRATION CALCULATIONS:
The maximum overland flow distance is 50.00 (Ft)
for the top area slope value of 0.01 %, in a development type of
General Commercial
In Accordance With Figure 3-3
Initial Area Time of Concentration= 16.54 minutes
TC= [1.8*(1.l-C)*distance(Ft.)A.5)/(% slopeA(l/3)]
TC= [1.8*(1.1-0.8200)*( 50.000A.5)/( 0.0l0A(l/3)]= 16.54
Rainfall intensity (I} = 3.410(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for area (Q=KCIA) is C = 0.820
Subarea runoff= 0.028(CFS)
Total initial stream area= 0.0l0(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2050.000 to Point/Station 2051.000
**** IRREGULAR CHANNEL FLOW TRAVEL TIME****
Estimated mean flow rate at midpoint of channel
Depth of flow= 0.194(Ft.), Average velocity=
******* Irregular Channel Data***********
Information entered for subchannel number 1 :
Point number
1
2
3
4
'X' coordinate
0.00
0.50
1.50
2.00
'Y' coordinate
1.00
0.00
0.00
1.00
Manning's 'N' friction factor= 0.015
Sub-Channel flow 0.645{CFS)
flow top width= l.194(Ft.)
velocity= 3.030(Ft/s)
area= 0.213(Sq.Ft)
Froude number 1.265
Upstream point elevation=
Downstream point elevation
Flow length= 840.000(Ft.)
Travel time = 4.62 min.
320.000(Ft.)
310.000(Ft.)
Time of concentration= 21.16 min.
Depth of flow= 0.194(Ft.)
Average velocity= 3.030(Ft/s)
Total irregular channel flow= 0.645(CFS)
Irregular channel normal depth above invert elev.
Average velocity of channel(s) = 3.030(Ft/s)
Adding area flow to channel
User specified 'C' value of 0.490 given for subarea
0.645(CFS)
3.030(Ft/s)
0.194(Ft.)
Rainfall intensity= 2.909(In/Hr) for a 100.0 year storm
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Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.490 CA= 0.407
Subarea runoff= 1.155(CFS) for 0.820(Ac.)
Total runoff= 1.183(CFS) Total area=
Depth of flow= 0.283(Ft.), Average velocity=
0.830(Ac.)
3.668(Ft/s)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2051.000 to Point/Station 2054.000
**** PIPEFLOW TRAVEL TIME (Program estimated size) ****
Upstream point/station elevation= 302.000(Ft.)
Downstream point/station elevation= 278.000(Ft.)
Pipe length = 97.00(Ft.) Manning's N = 0.011
No. of pipes= 1 Required pipe flow = 1.183(CFS)
Nearest computed pipe diameter = 6.00(In.)
Calculated individual pipe flow = 1.183(CFS)
Normal flow depth in pipe= 2.48(In.)
Flow top width inside pipe= 5.91(In.)
Critical depth could not be calculated.
Pipe flow velocity= 15.41(Ft/s)
Travel time through pipe= 0.10 min.
Time of concentration (TC) = 21.27 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2050.000 to Point/Station 2053.000
**** CONFLUENCE OF MINOR STREAMS****
Along Main Stream number: 3 in normal stream number 1
Stream flow area= 0.830(Ac.)
Runoff from this stream= 1.183(CFS)
Time of concentration= 21.27 min.
Rainfall intensity= 2.900(In/Hr)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2052.000 to Point/Station 2053.000
**** INITIAL AREA EVALUATION****
Decimal fraction soil group A=
Decimal fraction soil group B
Decimal fraction soil group C
Decimal fraction soil group D
[COMMERCIAL area type
(General Commercial )
Impervious value, Ai= 0.850
Sub-Area C Value= 0.820
0.000
0.000
0.000
1.000
Initial subarea total flow distance
Highest elevation= 293.000(Ft.)
Lowest elevation= 287.000(Ft.)
276.000(Ft.)
Elevation difference= 6.000(Ft.) Slope= 2.174 %
INITIAL AREA TIME OF CONCENTRATION CALCULATIONS:
The maximum overland flow distance is 75.00 (Ft)
for the top area slope value of 2.17 %, in a development type of
General Commercial
In Accordance With Figure 3-3
Initial Area Time of Concentration= 3.37 minutes
TC= [1.8*(1.l-C)*distance(Ft.)A.5)/(% slopeA(l/3)]
TC= [1.8*(1.1-0.8200)*( 75.000A.5)/( 2.174A(l/3)]= 3.37
The initial area total distance of 276.00 (Ft.) entered leaves a
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remaining distance of 201.00 (Ft.)
Using Figure 3-4, the travel time for this distance is 2.02 minutes
for a distance of 201.00 (Ft.) and a slope of 2.17 %
with an elevation difference of 4.37(Ft.) from the end of the top area
Tt = [11.9*length(Mi)A3)/(elevation change(Ft.))]A.385 *60(min/hr)
= 2.024 Minutes
Tt=[(ll.9*0.0381A3)/( 4.37)]A.385= 2.02
Total initial area Ti= 3.37 minutes from Figure 3-3 formula plus
2.02 minutes from the Figure 3-4 formula= 5.39 minutes
Rainfall intensity (I) = 7.026(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for area (Q=KCIA) is C = 0.820
Subarea runoff= 9.333(CFS)
Total initial stream area= l.620(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2053.000 to Point/Station 2054.000
**** PIPEFLOW TRAVEL TIME (Program estimated size) ****
Upstream point/station elevation= 281.000(Ft.)
Downstream point/station elevation= 278.000(Ft.)
Pipe length = 252.00(Ft.) Manning's N = 0.011
No. of pipes= 1 Required pipe flow = 9.333(CFS)
Nearest computed pipe diameter = 18.00(In.)
Calculated individual pipe flow = 9.333(CFS)
Normal flow depth in pipe= 10.98(In.)
Flow top width inside pipe= 17.56(In.)
Critical Depth= 14.16(In.)
Pipe flow velocity= 8.27(Ft/s)
Travel time through pipe= 0.51 min.
Time of concentration (TC) = 5.90 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2053.000 to Point/Station 2054.000
**** CONFLUENCE OF MINOR STREAMS****
Along Main Stream number: 3 in normal stream number 2
Stream flow area= 1.620(Ac.)
Runoff from this stream= 9.333(CFS)
Time of concentration= 5.90 min.
Rainfall intensity= 6.629(In/Hr)
Summary of stream data:
Stream
No.
1
2
Qmax(l)
Qmax(2) =
Flow rate
(CFS)
1.183
9.333
1.000 *
0.437 *
1.000 *
1.000 *
TC
(min)
21.27
5.90
1.000 *
1.000 *
0.277 *
1.000 *
1.183)
9.333)
1.183)
9.333)
Total of 2 streams to confluence:
Flow rates before confluence point:
1.183 9.333
Rainfall Intensity
(In/Hr)
2.900
6.629
+
+ = 5.265
+
+ = 9.661
Maximum flow rates at confluence using above data:
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5.265 9.661
Area of streams before confluence:
0.830 1.620
Results of confluence:
Total flow rate= 9.661(CFS)
Time of concentration= 5.901 min.
Effective stream area after confluence= 2.450(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2054.000 to Point/Station 2055.000
**** PIPEFLOW TRAVEL TIME (Program estimated size) ****
Upstream point/station elevation= 278.000(Ft.)
Downstream point/station elevation 268.000(Ft.)
Pipe length = 67.00(Ft.) Manning's N = 0.013
No. of pipes= 1 Required pipe flow = 9.661(CFS)
Nearest computed pipe diameter = 12.00(In.)
Calculated individual pipe flow = 9.66l(CFS)
Normal flow depth in pipe= 7.41(In.)
Flow top width inside pipe= 11.66(In.)
Critical depth could not be calculated.
Pipe flow velocity= 18.97(Ft/s)
Travel time through pipe= 0.06 min.
Time of concentration (TC) = 5.96 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2055.000 to Point/Station 2055.000
**** SUBAREA FLOW ADDITION****
User specified 'C' value of 0.490 given for subarea
Time of concentration= 5.96 min.
Rainfall intensity= 6.587(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.490 CA= 1.720
Subarea runoff= 1.668(CFS) for l.060(Ac.)
Total runoff= 11.329(CFS) Total area= 3.510(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 2055.000 to Point/Station 2068.000
**** CONFLUENCE OF MAIN STREAMS****
The following data inside Main Stream is listed:
In Main Stream number: 3
Stream flow area= 3.510(Ac.)
Runoff from this stream= 11.329(CFS)
Time of concentration= 5.96 min.
Rainfall intensity= 6.587(In/Hr)
Summary of stream data:
Stream Flow rate TC Rainfall Intensity
No. (CFS) (min) (In/Hr)
1 84.378 9.34 4.930
2 18.752 8.62 5.192
3 11.329 5.96 6.587
Qmax(l) =
1.000 * 1.000 * 84.378) +
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0.950 * 1.000 * 18 .752) +
0.748 * 1. 000 * 11. 329) + = 110. 665
Qmax(2) =
1.000 * 0.923 * 84. 378) +
1. 000 * 1. 000 * 18.752) +
0.788 * 1. 000 * 11. 329) + 105.561
Qmax(3) =
1. 000 * 0.638 * 84.378) +
1.000 * 0.691 * 18.752) +
1. 000 * 1. 000 * 11.329) + = 78.142
Total of 3 main streams to confluence:
Flow rates before confluence point:
84.378 18.752 11 .329
Maximum flow rates at confluence using above data:
110.665 105.561 78 .142
Area of streams before confluence:
27.620 4.390 3.510
Results of confluence:
Total flow rate= 110.665(CFS)
~ime of concentration= 9.340 min.
Effective stream area afte~ confluence =
End of computations, total stud~ are =
3 5 . 5 2 0 ( Ac . )
3 5 . 5 2 0 ( Ac . )
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DETENTION BASIN DEPTH
vs
STORAGE
VS
DISCHARGE FROM OUTLET STRUCTURE
I:\00 l O 17\_ Commercial\Stonnwater\Drainage\LCTS Comm_Drainage Rpt_ Basin2 _Det_Hydromod-SWMP.Doc
-------------------
Calculations for Detention Basin with Hydromodification
Stage Detention Basin TOTAL S-inch pipe 10-inch pipe 30-inch pipe OutletQ Elevation (ft) Average Storage (ac-ft) STORAGE (ac (Hydromod) (Hydromod) Weir (cfs) (ft) Plan Area (sf) Area (cf) ft) (cfs) (cfs) (cfs) (cfs)
0.0 266.0 0 0 0.000 0.000 0.0 0.0 0.0 0.0 0
1.0 267.0 5,387 2,694 0.062 0.062 0.6 0.0 0.0 0.0 0.6
2.0 268.0 11,229 8,308 0.191 0.253 0.9 1.7 0.0 0.0 2.6
2.5 268.5 12,121 5,838 0.134 0.387 1.0 2.5 21.2 27.3 27.3
3.0 269.0 13,013 6,284 0.144 0.531 1.1 3.2 60.0 32.3 32.3
4.0 270.0 14,074 13,544 0.311 0.842 1.3 4.2 See 30-inch Q 40.5 40.5
5.0 271.0 15,168 14,621 0.336 1.177 1.5 5.0 See 30-inch Q 47.3 47.3
6.0 272.0 16,300 15,734 0.361 1.539 1.6 5.7 See 30-inch Q 53.2 53.2
7.0 273.0 17,491 16,896 0.388 1.926 1.8 6.3 See 30-inch Q 58.5 58.5
Detention Basin Depth vs Storage vs Discharge from Outlet Structure
Stage Storage (ac-ft) Outlet Q (cfs) (ft)
0.0 0.000 0.0
1.0 0.062 0.6
2.0 0.253 2.6
2.5 0.387 27.3
3.0 0.531 32.3
4.0 0.842 40.5
5.0 1.177 47.3
6.0 1.539 53.2
7.0 1.926 58.5
1:\001017\_Commercial\Stormwater\Drainage\Detention Basin with HydroMod\DET BASIN STORAGE W HYDROMOD
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****************************************************************************
HYDRAULICS ELEMENTS -II PROGRAM PACKAGE
STORAGE BASIN HYDROGRAPH ROUTING MODEL
****************************************************************************
(c) Copyright 1983-2012 Advanced Engineering Software (aes)
Ver. 19.0 Release Date: 06/01/2012 License ID 1423
Analysis prepared by:
************************** DESCRIPTION OF STUDY**************************
* BASIN 2 -DETENTION BASIN WITH HYDROMODIFICATION *
* *
* *
**************************************************************************
FILE NAME: 1290-10.DAT
TIME/DATE OF STUDY: 11:39 12/16/2013
ENTERED INFORMATION:
TOTAL NUMBER OF INFLOW HYDROGRAPH INTERVALS= 42
CONSTANT HYDROGRAPH TIME UNIT(MINUTES) = 9.000
ASSUMED INITIAL DEPTH(FEET) IN STORAGE BASIN= 0.00
ENTERED INFLOW HYDROGRAPH ORDINATES (CFS) :
*INTERVAL FLOW *INTERVAL FLOW *INTERVAL FLOW *
* NUMBER (CFS) * NUMBER (CFS) * NUMBER (CFS) *
* 1: 0.00* 2: 0.00* 3: 3.70*
* 4: 3.80* 5: 3.90* 6: 4.00*
* 7: 4.10* 8: 4.20* 9: 4.40*
* 10: 4.50* 11: 4.70* 12: 4.80*
* 13: 5.10* 14: 5.20* 15: 5.50*
* 16: 5.70* 17: 6.10* 18: 6.40*
* 19: 6.90* 20: 7.30* 21: 8.10*
* 22: 8.50* 23: 9.80* 24: 10.60*
* 25: 13.00* 26: 14.80* 27: 21.70*
* 28: 29.50* 29: 110.70* 30: 17.40*
* 31: 11.60* 32: 9.10* 33: 7.60*
* 34: 6.60* 35: 5.90* 36: 5.40*
* 37: 4.90* 38: 4.60* 39: 4.30*
* 40: 4.00* 41: 3.80* 42: 0.00*
-----==========-------------------------------------------------------------
DEPTH-VS.-STORAGE AND DEPTH-VS.-DISCHARGE INFORMATION:
TOTAL NUMBER OF BASIN DEPTH INFORMATION ENTRIES= 9
*BASIN-DEPTH STORAGE OUTFLOW **BASIN-DEPTH STORAGE OUTFLOW *
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* (FEET) (ACRE-FEET) (CFS) ** (FEET) (ACRE-FEET) (CFS) *
* 0.000 0.000 0.000** 1.000 0. 062 0.600*
* 2.000 0.253 2.600** 2.500 0.387 27.300*
* 3.000 0.531 32.300** 4.000 0.842 40.500*
* 5.000 1.117 47.300** 6.000 1. 539 53.200*
* 7.000 1. 926 58.500**
****************************************************************************
INITIAL BASIN DEPTH(FEET) = 0.00
INITIAL BASIN STORAGE(ACRE-FEET) = 0.00
INITIAL BASIN OUTFLOW(CFS) = 0.00
BASIN STORAGE, OUTFLOW AND DEPTH ROUTING VALUES:
INTERVAL {S-O*DT/2} {S+O*DT/2}
NUMBER (ACRE-FEET) (ACRE-FEET)
1 0.00000 0.00000
2 0.05828 0.06572
3 0.23688 0.26912
4 0.21779 0.55621
5 0.33079 0.73121
6 0.59097 1. 09303
7 0.82382 1.41018
8 1.20925 1.86875
9 1.56340 2.28860
WHERE S=STORAGE(AF);O=OUTFLOW(AF/MIN.);DT=UNIT(MIN.)
*UNIT-HYDROGRAPH STORAGE-BASIN ROUTING*
NOTE: COMPUTED BASIN DEPTH, OUTFLOW, AND STORAGE QUANTITIES
OCCUR AT THE GIVEN TIME. BASIN INFLOW VALUES REPRESENT THE
AVERAGE INFLOW DURING THE RECENT HYDROGRAPH UNIT INTERVAL;
GRAPH NOTATION: "I"=MEAN UNIT INFLOW; "O"=OUTFLOW AT GIVEN TIME
TIME INFLOW OUTFLOW STORAGE
(HOURS) (CFS) (CFS) (ACRE-FT) 0. 28. 55. 83.
0.15 0.00 0.00 0.000 0
[BASIN DEPTH(FEET) = 0.00]
0.30 0.00 0.00 0.000 O
[BASIN DEPTH(FEET) = 0.00]
0.45 3.70 0.42 0.043 or
[BASIN DEPTH(FEET) = 0. 70]
0.60 3.80 0.82 0.083 or
[BASIN DEPTH(FEET) = 1.11]
0.75 3.90 1.19 0 .119 or
[BASIN DEPTH(FEET) = 1. 30]
0.90 4.00 1. 53 0.151 or
[BASIN DEPTH(FEET) = 1. 47]
1.05 4.10 1.85 0.181 or
111.
1 1
I [BASIN DEPTH(FEET) = 1.62]
1. 20 4.20 2.13 0.209 OI
I [BASIN DEPTH(FEET) = 1. 77]
1. 35 4.40 2.41 0.235 OI
[BASIN DEPTH(FEET) = 1.91]
1. 50 4.50 3.17 0.256 OI I [BASIN DEPTH(FEET) = 2. 01]
1. 65 4.70 4.80 0.265 .0
[BASIN DEPTH(FEET) = 2.04]
I 1. 80 4.80 4.80 0. 265 .0
[BASIN DEPTH(FEET) = 2.04]
1. 95 5.10 5.12 0.267 .0
I [BASIN DEPTH(FEET) = 2.05]
2.10 5.20 5.21 0.267 .0
[BASIN DEPTH(FEET) = 2.05]
2.25 5.50 5.52 0.269 .0
I [BASIN DEPTH(FEET) = 2. 06]
2.40 5.70 5.71 0.270 .0
[BASIN DEPTH(FEET) = 2. 06]
I 2.55 6.10 6 .13 0. 272 .0
[BASIN DEPTH(FEET) = 2. 07 l
2.70 6.40 6.42 0.274 .0
[BASIN DEPTH(FEET) = 2.08] I 2.85 6.90 6.93 0. 277 .IO
[BASIN DEPTH(FEET) = 2. 09]
3.00 7.30 7.32 0. 279 0
I [BASIN DEPTH(FEET) = 2.10]
3.15 8.10 8.15 0.283 0
[BASIN DEPTH(FEET) = 2 .11]
I 3.30 8.50 8.52 0.285 0
[BASIN DEPTH(FEET) = 2.12]
3.45 9.80 9.88 0.293 0
[BASIN DEPTH(FEET) = 2.15]
I 3.60 10.60 10.65 0.297 0
[BASIN DEPTH(FEET) = 2 .16]
3.75 13. 00 13 .16 0.310 0
I [BASIN DEPTH(FEET) = 2.21]
3.90 14.80 14.91 0.320 0
[BASIN DEPTH(FEET) = 2.25]
I 4.05 21. 70 22.15 0.359 0
[BASIN DEPTH(FEET) = 2.40]
4.20 29.50 28.19 0. 413 0
[BASIN DEPTH(FEET) = 2. 59]
I 4.35 110. 70 49.87 1. 301 0 I
[BASIN DEPTH(FEET) = s. 44 J
4.50 17.40 42. 96 0.941 I 0
I [BASIN DEPTH(FEET) = 4. 36]
4.65 11. 60 34.29 0.606 I .0
[BASIN DEPTH(FEET) = 3.24]
4.80 9 .10 23.04 0.364 I 0
I [BASIN DEPTH(FEET) = 2.41]
4.95 7.60 6.57 0.275 .OI
[BASIN DEPTH(FEET) = 2.08]
I 5.10 6.60 6.60 0.275 .0
I
I
I [BASIN DEPTH(FEET) = 2.08]
5.25 5.90 5.85 0. 271 .0
I [BASIN DEPTH(FEET) = 2.07]
5.40 5.40 5.37 0.268 .o
[BASIN DEPTH(FEET) = 2. 06]
5.55 4.90 4.87 0. 265 .o I [BASIN DEPTH(FEET) = 2.05]
5.70 4.60 4.58 0. 264 .0
[BASIN DEPTH(FEET) = 2. 04 J
I 5.85 4.30 4.28 0. 262 .0
[BASIN DEPTH (FEET) = 2.03]
6.00 4.00 3.98 0.260 .o
I [BASIN DEPTH(FEET) = 2. 03]
6.15 3.80 3.79 0.259 .0
[BASIN DEPTH(FEET) = 2.02]
6.30 0.00 2.27 0.222 0
I [BASIN DEPTH(FEET) = 1. 84 J
6.45 0.00 2.00 0.195 0
[BASIN DEPTH(FEET) = 1.70]
I 6.60 0.00 1. 75 0.172 0
[BASIN DEPTH(FEET) = 1. 58]
6.75 0.00 1. 54 0.152 0
[BASIN DEPTH(FEET) = 1.47] I 6.90 0.00 1. 35 0 .134 0
[BASIN DEPTH(FEET) = 1. 38]
7.05 0.00 1.19 0. 118 0
I [BASIN DEPTH (FEET) = 1. 29]
7.20 0.00 1.04 0.104 0
[BASIN DEPTH(FEET) = 1. 22]
I 7.35 0.00 0.92 0.092 0
[BASIN DEPTH(FEET) = 1.16]
7.50 0.00 0.80 0.081 0
[BASIN DEPTH (FEET) = 1.10]
I 7.65 0.00 0.71 0.072 0
[BASIN DEPTH(FEET) = 1.05]
7.80 0.00 0.62 0.064 0
I [BASIN DEPTH(FEET) = 1. 01 J
7.95 0.00 0.55 0.057 O
[BASIN DEPTH(FEET) = 0.91]
8.10 0.00 0.49 0.050 O I [BASIN DEPTH(FEET) = 0.81]
8.25 0.00 0.43 0.045 0
[BASIN DEPTH(FEET) = 0. 72]
I 8.40 0.00 0.38 0.040 0
[BASIN DEPTH(FEET) = 0.64]
8.55 0.00 0.34 0.035 0
I [BASIN DEPTH(FEET) = 0.57]
8.70 0.00 0.30 0.031 0
[BASIN DEPTH(FEET) = 0.50]
8.85 0.00 0.27 0.028 O
I [BASIN DEPTH(FEET) = 0.44]
9.00 0.00 0.24 0.024 0
[BASIN DEPTH(FEET) = 0. 39]
I 9.15 0.00 0.21 0.022 0
I
I
I [BASIN DEPTH(FEET) = 0.35]
9.30 0.00 0.19 0.019 0
I [BASIN DEPTH(FEET) = 0.31]
9.45 0.00 0.16 0. 017 0
[BASIN DEPTH(FEET) = 0.27]
9.60 0.00 0.15 0.015 O
I [BASIN DEPTH(FEET) = 0.24]
9.75 0.00 0 .13 0. 013 0
[BASIN DEPTH(FEET) = 0.22]
I 9.90 0.00 0.12 0.012 0
[BASIN DEPTH (FEET) = 0 .19]
10.05 0.00 0.10 0. 011 0
I [BASIN DEPTH(FEET) = 0.17]
10.20 0.00 0.09 0.009 0
[BASIN DEPTH(FEET) = 0.15]
10.35 0.00 0.08 0.008 0
I [BASIN DEPTH(FEET) = 0.13]
10.50 0.00 0.07 0.007 0
[BASIN DEPTH(FEET) = 0.12]
I 10.65 0.00 0.06 0.007 0
[BASIN DEPTH(FEET) = 0.11]
10.80 0.00 0.06 0.006 0
[BASIN DEPTH(FEET) = 0. 09] I 10.95 0.00 0.05 0.005 0
[BASIN DEPTH(FEET) = 0.08]
11.10 0.00 0.04 0.005 0
I [BASIN DEPTH(FEET) = 0.07]
11. 25 0.00 0.04 0.004 0
[BASIN DEPTH(FEET) = 0.07]
I 11. 40 0.00 0.03 0.004 0
[BASIN DEPTH (FEET) = 0. 06]
11. 55 0.00 0.03 0.003 0
[BASIN DEPTH(FEET) = 0.05]
I 11. 70 0.00 0.03 0.003 0
[BASIN DEPTH(FEET) = 0.05]
11. 85 0.00 0.02 0.002 0
I [BASIN DEPTH(FEET) = 0.04]
12.00 0.00 0.02 0.002 O
[BASIN DEPTH(FEET) = 0.04]
12.15 0.00 0.02 0.002 0 I [BASIN DEPTH(FEET) = 0. 03]
12.30 0.00 0.02 0.002 0
[BASIN DEPTH(FEET) = 0.03]
I 12.45 0.00 0.01 0.002 0
[BASIN DEPTH(FEET) = 0.02]
12.60 0.00 0.01 0.001 0
I [BASIN DEPTH(FEET) = 0.02]
12.75 0.00 0.01 0.001 0
[BASIN DEPTH(FEET) = 0.02]
12.90 0.00 0.01 0.001 0
I [BASIN DEPTH(FEET) = 0.02]
13. 05 0.00 0.01 0.001 0
[BASIN DEPTH(FEET) = 0.02]
I 13. 20 0.00 0.01 0.001 O
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
[BASIN
13.35
[BASIN
13. 50
[BASIN
13. 65
[BASIN
13. 80
[BASIN
13.95
[BASIN
14.10
[BASIN
14.25
[BASIN
14.40
[BASIN
14.55
[BASIN
14.70
[BASIN
14.85
[BASIN
15.00
[BASIN
DEPTH(FEET) =
0.00 0.01
DEPTH(FEET) =
0.00 0.01
DEPTH(FEET) =
0.00 0.01
DEl?TH(FEET) =
0.00 0.01
DEPTH(FEET) =
0.00 0.00
DEPTH(FEET) =
0.00 0.00
DEPTH(FEET) =
0.00 0.00
DEPTH(FEET) =
0.00 0.00
DEPTH(FEET) =
0.00 0.00
DEPTH(FEET) =
0.00 0.00
DEPTH(FEET) =
0.00 0.00
DEPTH(FEET) =
0.00 0.00
DEPTH (FEET) =
0.01]
0.001 0
0. 01]
0.001 O
0.01)
0.001 0
0.01]
0.001 O
0.01)
0.000 0
0.01)
0.000 0
0.01)
0.000 O
0.01)
0.000 0
0.01)
0.000 O
0. 00)
0.000 O
0.00)
0.000 O
0.00]
0.000 0
0.00)
FLOW INTO EXISTING BASIN INCREASED TO 120 CFS TO ACCOUNT FOR ADDITIONAL 2.5-ACRE DRAINAGE AREA FROM LCTC PROJECT SITEREVISED ROUTING ANALYSIS: QEXIST = 54.8QPROP (UNDET) = 119.8 CFS QPROP (DET) = 48.8 CFSSTREAM "1"O'DAY NODES 2000THROUGH 2068A = 27.62 ACtc = 9.34 MINQ = 84.38 CFSSTREAM "2"O'DAY NODES 2040THROUGH 2068A=4.39ACtc = 8.62 MINQ=18.75CFSSTREAM "3"SB&O NODES 2040THROUGH 2068A=4.98ACtc = 7.49 MINQ = 20.35 CFS
I
I
\
\
I
\
\
\(
'f'
\
\
\
\
\ '1
\\
\\
• \"' ,,\
'
\ '\ \
\ \\;:
\ ,,
Revised Confluence Calculation
____________________________________________________________________________
****************************************************************************
RATIONAL METHOD HYDROLOGY COMPUTER PROGRAM PACKAGE
Reference: SAN DIEGO COUNTY FLOOD CONTROL DISTRICT
2003,1985,1981 HYDROLOGY MANUAL
(c) Copyright 1982‐2016 Advanced Engineering Software (aes)
Ver. 23.0 Release Date: 07/01/2016 License ID 1532
Analysis prepared by:
Tory R. Walker Engineering, Inc.
122 Civic Center Drive
Suite 206
Vista, CA 92084
************************** DESCRIPTION OF STUDY **************************
* LA COSTA TOWN SQUARE *
* ADDITION OF ONSITE 100‐YEAR PEAK FLOW TO EXISTING DETENTION BASIN *
* 100‐YEAR RATIONAL METHOD HYDROGRAPH *
**************************************************************************
FILE NAME: LCTS100.DAT
TIME/DATE OF STUDY: 14:31 12/01/2022
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
USER SPECIFIED HYDROLOGY AND HYDRAULIC MODEL INFORMATION:
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
2003 SAN DIEGO MANUAL CRITERIA
USER SPECIFIED STORM EVENT(YEAR) = 100.00
6‐HOUR DURATION PRECIPITATION (INCHES) = 2.900
SPECIFIED MINIMUM PIPE SIZE(INCH) = 18.00
SPECIFIED PERCENT OF GRADIENTS(DECIMAL) TO USE FOR FRICTION SLOPE = 0.95
SAN DIEGO HYDROLOGY MANUAL "C"‐VALUES USED FOR RATIONAL METHOD
NOTE: CONSIDER ALL CONFLUENCE STREAM COMBINATIONS
FOR ALL DOWNSTREAM ANALYSES
*USER‐DEFINED STREET‐SECTIONS FOR COUPLED PIPEFLOW AND STREETFLOW MODEL*
HALF‐ CROWN TO STREET‐CROSSFALL: CURB GUTTER‐GEOMETRIES: MANNING
WIDTH CROSSFALL IN‐ / OUT‐/PARK‐ HEIGHT WIDTH LIP HIKE FACTOR
NO. (FT) (FT) SIDE / SIDE/ WAY (FT) (FT) (FT) (FT) (n)
=== ===== ========= ================= ====== ===== ====== ===== =======
1 30.0 20.0 0.018/0.018/0.020 0.67 2.00 0.0313 0.167 0.0150
GLOBAL STREET FLOW‐DEPTH CONSTRAINTS:
1. Relative Flow‐Depth = 0.00 FEET
as (Maximum Allowable Street Flow Depth) ‐ (Top‐of‐Curb)
2. (Depth)*(Velocity) Constraint = 6.0 (FT*FT/S)
*SIZE PIPE WITH A FLOW CAPACITY GREATER THAN
OR EQUAL TO THE UPSTREAM TRIBUTARY PIPE.*
****************************************************************************
FLOW PROCESS FROM NODE 2067.00 TO NODE 2068.00 IS CODE = 7
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
>>>>>USER SPECIFIED HYDROLOGY INFORMATION AT NODE<<<<<
============================================================================
USER‐SPECIFIED VALUES ARE AS FOLLOWS:
TC(MIN) = 9.34 RAIN INTENSITY(INCH/HOUR) = 5.11
TOTAL AREA(ACRES) = 27.62 TOTAL RUNOFF(CFS) = 84.38
****************************************************************************
FLOW PROCESS FROM NODE 2068.00 TO NODE 2068.00 IS CODE = 1
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
>>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<<<<<
============================================================================
TOTAL NUMBER OF STREAMS = 3
CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 1 ARE:
TIME OF CONCENTRATION(MIN.) = 9.34
RAINFALL INTENSITY(INCH/HR) = 5.11
TOTAL STREAM AREA(ACRES) = 27.62
PEAK FLOW RATE(CFS) AT CONFLUENCE = 84.38
****************************************************************************
FLOW PROCESS FROM NODE 2042.00 TO NODE 2068.00 IS CODE = 7
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
>>>>>USER SPECIFIED HYDROLOGY INFORMATION AT NODE<<<<<
============================================================================
USER‐SPECIFIED VALUES ARE AS FOLLOWS:
TC(MIN) = 8.62 RAIN INTENSITY(INCH/HOUR) = 5.38
TOTAL AREA(ACRES) = 4.39 TOTAL RUNOFF(CFS) = 18.75
****************************************************************************
FLOW PROCESS FROM NODE 2068.00 TO NODE 2068.00 IS CODE = 1
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
>>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<<<<<
============================================================================
TOTAL NUMBER OF STREAMS = 3
CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 2 ARE:
TIME OF CONCENTRATION(MIN.) = 8.62
RAINFALL INTENSITY(INCH/HR) = 5.38
TOTAL STREAM AREA(ACRES) = 4.39
PEAK FLOW RATE(CFS) AT CONFLUENCE = 18.75
****************************************************************************
FLOW PROCESS FROM NODE 2054.00 TO NODE 2055.00 IS CODE = 7
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
>>>>>USER SPECIFIED HYDROLOGY INFORMATION AT NODE<<<<<
============================================================================
USER‐SPECIFIED VALUES ARE AS FOLLOWS:
TC(MIN) = 7.49 RAIN INTENSITY(INCH/HOUR) = 5.89
TOTAL AREA(ACRES) = 4.98 TOTAL RUNOFF(CFS) = 20.35
****************************************************************************
FLOW PROCESS FROM NODE 2068.00 TO NODE 2068.00 IS CODE = 1
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
>>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<<<<<
>>>>>AND COMPUTE VARIOUS CONFLUENCED STREAM VALUES<<<<<
============================================================================
TOTAL NUMBER OF STREAMS = 3
CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 3 ARE:
TIME OF CONCENTRATION(MIN.) = 7.49
RAINFALL INTENSITY(INCH/HR) = 5.89
TOTAL STREAM AREA(ACRES) = 4.98
PEAK FLOW RATE(CFS) AT CONFLUENCE = 20.35
** CONFLUENCE DATA **
STREAM RUNOFF Tc INTENSITY AREA
NUMBER (CFS) (MIN.) (INCH/HOUR) (ACRE)
1 84.38 9.34 5.106 27.62
2 18.75 8.62 5.377 4.39
3 20.35 7.49 5.887 4.98
RAINFALL INTENSITY AND TIME OF CONCENTRATION RATIO
CONFLUENCE FORMULA USED FOR 3 STREAMS.
** PEAK FLOW RATE TABLE **
STREAM RUNOFF Tc INTENSITY
NUMBER (CFS) (MIN.) (INCH/HOUR)
1 104.31 7.49 5.887
2 115.21 8.62 5.377
3 119.83 9.34 5.106
COMPUTED CONFLUENCE ESTIMATES ARE AS FOLLOWS:
PEAK FLOW RATE(CFS) = 119.83 Tc(MIN.) = 9.34
TOTAL AREA(ACRES) = 37.0
LONGEST FLOWPATH FROM NODE 0.00 TO NODE 2068.00 = 0.00 FEET.
============================================================================
END OF STUDY SUMMARY:
TOTAL AREA(ACRES) = 37.0 TC(MIN.) = 9.34
PEAK FLOW RATE(CFS) = 119.83
*** PEAK FLOW RATE TABLE ***
Q(CFS) Tc(MIN.)
1 104.31 7.49
2 115.21 8.62
3 119.83 9.34
============================================================================
============================================================================
END OF RATIONAL METHOD ANALYSIS
Revised Regional Hydrograph
Rational Method Hydrograph Calculations
for Post Developed Conditions into Regional Detention Basin
La Costa Town Square, Carlsbad, CA
Q100=120 cfs
Tc=9 min C=0.63
#= 40 P100,6=2.9 in A=37 acres
(7.44*P6*D^-.645)(I*D/60)(V1-V0)(∆V/∆T)(Q=ciA)(Re-ordered)
D I VOL ∆VOL I (INCR)Q VOL ORDINATE
#(MIN)(IN/HR)(IN)(IN)(IN/HR)(CFS)(CF)SUM=
0 0 0.00 0.00 0.78 5.23 119.83 64708
1 9 5.23 0.78 0.22 1.46 34.24 18490 4.14
2 18 3.34 1.00 0.16 1.04 24.30 13123 4.21
3 27 2.57 1.16 0.12 0.83 19.49 10525 4.36
4 36 2.14 1.28 0.11 0.71 16.55 8937 4.44
5 45 1.85 1.39 0.09 0.62 14.53 7847 4.61
6 54 1.65 1.48 0.08 0.56 13.04 7042 4.71
7 63 1.49 1.57 0.08 0.51 11.89 6420 4.91
8 72 1.37 1.64 0.07 0.47 10.96 5921 5.02
9 81 1.27 1.71 0.07 0.43 10.20 5510 5.26
10 90 1.18 1.78 0.06 0.41 9.57 5165 5.40
11 99 1.11 1.84 0.06 0.38 9.02 4870 5.69
12 108 1.05 1.90 0.05 0.36 8.55 4615 5.85
13 117 1.00 1.95 0.05 0.35 8.13 4392 6.21
14 126 0.95 2.00 0.05 0.33 7.77 4194 6.41
15 135 0.91 2.05 0.05 0.32 7.44 4017 6.88
16 144 0.87 2.10 0.05 0.30 7.14 3858 7.14
17 153 0.84 2.14 0.04 0.29 6.88 3714 7.77
18 162 0.81 2.19 0.04 0.28 6.64 3583 8.13
19 171 0.78 2.23 0.04 0.27 6.41 3464 9.02
20 180 0.76 2.27 0.04 0.26 6.21 3354 9.57
21 189 0.73 2.31 0.04 0.26 6.02 3252 10.96
22 198 0.71 2.35 0.04 0.25 5.85 3158 11.89
23 207 0.69 2.39 0.04 0.24 5.69 3071 14.53
24 216 0.67 2.42 0.04 0.24 5.54 2989 16.55
25 225 0.66 2.46 0.03 0.23 5.40 2913 24.30
26 234 0.64 2.49 0.03 0.22 5.26 2842 34.24
27 243 0.62 2.53 0.03 0.22 5.14 2775 119.83
28 252 0.61 2.56 0.03 0.21 5.02 2712 19.49
29 261 0.60 2.59 0.03 0.21 4.91 2652 13.04
30 270 0.58 2.62 0.03 0.20 4.81 2596 10.20
31 279 0.57 2.65 0.03 0.20 4.71 2542 8.55
32 288 0.56 2.68 0.03 0.20 4.61 2491 7.44
33 297 0.55 2.71 0.03 0.19 4.52 2443 6.64
34 306 0.54 2.74 0.03 0.19 4.44 2397 6.02
35 315 0.53 2.77 0.03 0.19 4.36 2353 5.54
36 324 0.52 2.80 0.03 0.18 4.28 2312 5.14
37 333 0.51 2.83 0.03 0.18 4.21 2272 4.81
38 342 0.50 2.85 0.03 0.18 4.14 2233 4.52
39 351 0.49 2.88 0.03 0.17 4.07 2197 4.28
40 360 0.48 2.91 0.00 0.00 0.00 0 4.07
SUM=243949 cubic feet
666-01 Q100 Hydrograph - Regional 12/1/2022
Rational Method Hydrograph Calculations
for Post Developed Conditions into Regional Detention Basin
La Costa Town Square, Carlsbad, CA
D I VOL ∆VOL I (INCR)Q VOL ORDINATE
#(MIN)(IN/HR)(IN)(IN)(IN/HR)(CFS)(CF)SUM=
5.60 acre-feet
Check:V = C*A*P6
V=5.67 acre-feet
OK
666-01 Q100 Hydrograph - Regional 12/1/2022
SWMM Detention Routing
Input & Output
[TITLE];;Project Title/NotesLa Costa Town Square Q100 (Mitigated) ‐ POC‐1[OPTIONS];;Option ValueFLOW_UNITS CFSINFILTRATION GREEN_AMPTFLOW_ROUTING KINWAVELINK_OFFSETS DEPTHMIN_SLOPE 0ALLOW_PONDING NOSKIP_STEADY_STATE NOSTART_DATE 01/01/2000START_TIME 00:00:00REPORT_START_DATE 01/01/2000REPORT_START_TIME 00:00:00END_DATE 01/01/2000END_TIME 12:00:00SWEEP_START 01/01SWEEP_END 12/31DRY_DAYS 0REPORT_STEP 00:01:00WET_STEP 00:01:00DRY_STEP 00:01:00ROUTING_STEP 0:01:00 RULE_STEP 00:00:00INERTIAL_DAMPING PARTIALNORMAL_FLOW_LIMITED BOTHFORCE_MAIN_EQUATION H‐WVARIABLE_STEP 0.75LENGTHENING_STEP 0MIN_SURFAREA 12.557MAX_TRIALS 8HEAD_TOLERANCE 0.005SYS_FLOW_TOL 5LAT_FLOW_TOL 5MINIMUM_STEP 0.5THREADS 1[EVAPORATION];;Data Source Parameters;;‐‐‐‐‐‐‐‐‐‐‐‐‐‐ ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐MONTHLY 0.030 0.050 0.080 0.110 0.130 0.150 0.150 0.130 0.110 0.080 0.040 0.020 DRY_ONLY NO[OUTFALLS];;Name Elevation Type Stage Data Gated Route To ;;‐‐‐‐‐‐‐‐‐‐‐‐‐‐ ‐‐‐‐‐‐‐‐‐‐ ‐‐‐‐‐‐‐‐‐‐ ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐ ‐‐‐‐‐‐‐‐ ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐POC‐1_Q100 0 FREE NO [STORAGE];;Name Elev. MaxDepth InitDepth Shape Curve Type/Params SurDepth Fevap Psi Ksat IMD
;;‐‐‐‐‐‐‐‐‐‐‐‐‐‐ ‐‐‐‐‐‐‐‐ ‐‐‐‐‐‐‐‐‐‐ ‐‐‐‐‐‐‐‐‐‐‐ ‐‐‐‐‐‐‐‐‐‐ ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐ ‐‐‐‐‐‐‐‐‐ ‐‐‐‐‐‐‐‐ ‐‐‐‐‐‐‐‐ ‐‐‐‐‐‐‐‐BASIN‐2 266 7 0 TABULAR STOR_2 0 0 [OUTLETS];;Name From Node To Node Offset Type QTable/Qcoeff Qexpon Gated ;;‐‐‐‐‐‐‐‐‐‐‐‐‐‐ ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐ ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐ ‐‐‐‐‐‐‐‐‐‐ ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐ ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐ ‐‐‐‐‐‐‐‐‐‐ ‐‐‐‐‐‐‐‐OUT_2 BASIN‐2 POC‐1_Q100 0 TABULAR/DEPTH OUT_1 NO [INFLOWS];;Node Constituent Time Series Type Mfactor Sfactor Baseline Pattern;;‐‐‐‐‐‐‐‐‐‐‐‐‐‐ ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐ ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐ ‐‐‐‐‐‐‐‐ ‐‐‐‐‐‐‐‐ ‐‐‐‐‐‐‐‐ ‐‐‐‐‐‐‐‐ ‐‐‐‐‐‐‐‐BASIN‐2 FLOW Q100 FLOW 1.0 1.0 [CURVES];;Name Type X‐Value Y‐Value ;;‐‐‐‐‐‐‐‐‐‐‐‐‐‐ ‐‐‐‐‐‐‐‐‐‐ ‐‐‐‐‐‐‐‐‐‐ ‐‐‐‐‐‐‐‐‐‐OUT_1 Rating 0 0 OUT_1 1 0.6 OUT_1 2 2.6 OUT_1 2.5 27.3 OUT_1 3 32.3 OUT_1 4 40.5 OUT_1 5 47.3 OUT_1 6 53.2 OUT_1 7 58.5 ;STOR_2 Storage 0 0 STOR_2 1 5387 STOR_2 2 11229 STOR_2 2.5 12121 STOR_2 3 13013 STOR_2 4 14074 STOR_2 5 15168 STOR_2 6 16300 STOR_2 7 17491 [TIMESERIES];;Name Date Time Value ;;‐‐‐‐‐‐‐‐‐‐‐‐‐‐ ‐‐‐‐‐‐‐‐‐‐ ‐‐‐‐‐‐‐‐‐‐ ‐‐‐‐‐‐‐‐‐‐Q100 0:00 0 Q100 0:09 4.14 Q100 0:18 4.21 Q100 0:27 4.36 Q100 0:36 4.44 Q100 0:45 4.61 Q100 0:54 4.71 Q100 1:03 4.91 Q100 1:12 5.02 Q100 1:21 5.26 Q100 1:30 5.40 Q100 1:39 5.69 Q100 1:48 5.85 Q100 1:57 6.21 Q100 2:06 6.41 Q100 2:15 6.88
Q100 2:24 7.14 Q100 2:33 7.77 Q100 2:42 8.13 Q100 2:51 9.02 Q100 3:00 9.57 Q100 3:09 10.96 Q100 3:18 11.89 Q100 3:27 14.53 Q100 3:36 16.55 Q100 3:45 24.30 Q100 3:54 34.24 Q100 4:03 119.83 Q100 4:12 19.49 Q100 4:21 13.04 Q100 4:30 10.20 Q100 4:39 8.55 Q100 4:48 7.44 Q100 4:57 6.64 Q100 5:06 6.02 Q100 5:15 5.54 Q100 5:24 5.14 Q100 5:33 4.81 Q100 5:42 4.52 Q100 5:51 4.28 Q100 6:00 4.07 [REPORT];;Reporting OptionsSUBCATCHMENTS ALLNODES ALLLINKS ALL[TAGS][MAP]DIMENSIONS 191.920 4920.830 1021.827 5718.627Units None[COORDINATES];;Node X‐Coord Y‐Coord ;;‐‐‐‐‐‐‐‐‐‐‐‐‐‐ ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐ ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐POC‐1_Q100 543.726 5281.929 BASIN‐2 533.053 5425.123 [VERTICES];;Link X‐Coord Y‐Coord ;;‐‐‐‐‐‐‐‐‐‐‐‐‐‐ ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐ ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
EPA STORM WATER MANAGEMENT MODEL ‐ VERSION 5.2 (Build 5.2.1) ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐ La Costa Town Square Q100 (Mitigated) ‐ POC‐1 **************** Analysis Options **************** Flow Units ............... CFS Process Models: Rainfall/Runoff ........ NO RDII ................... NO Snowmelt ............... NO Groundwater ............ NO Flow Routing ........... YES Ponding Allowed ........ NO Water Quality .......... NO Flow Routing Method ...... KINWAVE Starting Date ............ 01/01/2000 00:00:00 Ending Date .............. 01/01/2000 12:00:00 Antecedent Dry Days ...... 0.0 Report Time Step ......... 00:01:00 Routing Time Step ........ 60.00 sec ************************** Volume Volume Flow Routing Continuity acre‐feet 10^6 gal ************************** ‐‐‐‐‐‐‐‐‐ ‐‐‐‐‐‐‐‐‐ Dry Weather Inflow ....... 0.000 0.000 Wet Weather Inflow ....... 0.000 0.000 Groundwater Inflow ....... 0.000 0.000 RDII Inflow .............. 0.000 0.000 External Inflow .......... 5.572 1.816 External Outflow ......... 5.577 1.817 Flooding Loss ............ 0.000 0.000 Evaporation Loss ......... 0.000 0.000 Exfiltration Loss ........ 0.000 0.000 Initial Stored Volume .... 0.000 0.000 Final Stored Volume ...... 0.000 0.000 Continuity Error (%) ..... ‐0.078 ******************************** Highest Flow Instability Indexes ******************************** All links are stable. ************************* Routing Time Step Summary ************************* Minimum Time Step : 60.00 sec Average Time Step : 60.00 sec Maximum Time Step : 60.00 sec
% of Time in Steady State : 0.00 Average Iterations per Step : 1.00 % of Steps Not Converging : 0.00 ****************** Node Depth Summary ****************** ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐ Average Maximum Maximum Time of Max Reported Depth Depth HGL Occurrence Max Depth Node Type Feet Feet Feet days hr:min Feet ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐ POC‐1_Q100 OUTFALL 0.00 0.00 0.00 0 00:00 0.00 BASIN‐2 STORAGE 1.38 5.26 271.26 0 04:10 5.26 ******************* Node Inflow Summary ******************* ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐ Maximum Maximum Lateral Total Flow Lateral Total Time of Max Inflow Inflow Balance Inflow Inflow Occurrence Volume Volume Error Node Type CFS CFS days hr:min 10^6 gal 10^6 gal Percent ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐ POC‐1_Q100 OUTFALL 0.00 48.81 0 04:10 0 1.82 0.000 BASIN‐2 STORAGE 119.83 119.83 0 04:04 1.82 1.82 ‐0.078 ********************* Node Flooding Summary ********************* No nodes were flooded. ********************** Storage Volume Summary ********************** ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐ Average Avg Evap Exfil Maximum Max Time of Max Maximum Volume Pcnt Pcnt Pcnt Volume Pcnt Occurrence Outflow Storage Unit 1000 ft³ Full Loss Loss 1000 ft³ Full days hr:min CFS ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐ BASIN‐2 7.893 9 0 0 55.210 66 0 04:10 48.81 *********************** Outfall Loading Summary ***********************
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐ Flow Avg Max Total Freq Flow Flow Volume Outfall Node Pcnt CFS CFS 10^6 gal ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐ POC‐1_Q100 83.47 6.74 48.81 1.817 ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐ System 83.47 6.74 48.81 1.817 ******************** Link Flow Summary ******************** ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐ Maximum Time of Max Maximum Max/ Max/ |Flow| Occurrence |Veloc| Full Full Link Type CFS days hr:min ft/sec Flow Depth ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐ OUT_2 DUMMY 48.81 0 04:10 ************************* Conduit Surcharge Summary ************************* No conduits were surcharged. Analysis begun on: Thu Dec 1 14:40:05 2022 Analysis ended on: Thu Dec 1 14:40:05 2022 Total elapsed time: < 1 sec
D:\76882 La Costa Town Square\13 Reports\Hydrology\La Costa, Drainage Study 2022 0210.docx Page 14
EXHIBIT D
SWMM Data Table
HY-8 Analysis
Prepared by:
___________________________________ Tory R. Walker, PE
R.C.E. 45005
TECHNICAL MEMORANDUM
SWMM Modeling for
Hydromodification Compliance at POC-1
La Costa Town Square
Carlsbad, CA
Project No. CT 2017-0003
Prepared for:
Woodside 05S, LP
1250 Corona Pointe Court, Suite 500
Corona, CA 92879
(951) 363-0369
December 2022
~,11111111111111 TORY R. WALKER
~.,..__.:ll ENGINEERING
WATERSHED, FLOODPLAIN & STORMWATER MANAGEMENT | RIVER RESTORATION | FLOOD FACILITIES DESIGN | SEDIMENT & EROSION
122 CIVIC CENTER DRIVE, SUITE 206, VISTA, CA 92084 | (760) 414-9212 | TRWENGINEERING.COM
TECHNICAL MEMORANDUM
Date: December 2022
To: Woodside 05S, LP
1250 Corona Pointe Court, Suite 500
Corona, CA 92879
(951) 363-0369
From: Tory Walker, PE, CFM, LEED GA
Subject: Summary of SWMM Modeling for Hydromodification Compliance at POC-1 for
La Costa Town Square, City of Carlsbad, CA.
INTRODUCTION
This technical memorandum summarizes the approach used to model the proposed La Costa
Town Square development project in the City of Carlsbad, CA, using the Environmental Protection
Agency (EPA) Storm Water Management Model (SWMM). SWMM analyses were prepared for the
pre- and post-developed conditions at the project site to determine if the proposed flow control
facility basin meets Hydromodification Management Plan (HMP) requirements. The San Diego
Regional Water Quality Control Board (SDRWQCB) established these requirements in the Model
BMP Design Manual San Diego Region1 (BMPDM) for the County of San Diego Copermittees,
which includes the City of Carlsbad.
SWMM MODEL DEVELOPMENT
The project proposes to subdivide and develop a property located north of the intersection of La
Costa Avenue and Calle Timiteo, in the City of Carlsbad. Two (2) SWMM scenarios were prepared
for this study, one for the pre-developed and another for the post-developed conditions. This
study analyzes the pre-to-post project flow rates and durations at one Point of Compliance (POC-
1). POC-1 is located at the western end project site, at the existing outfall draining to the existing
detention basin (as shown on the DMA Exhibit in SWQMP Attachment 1A). The existing detention
basin was constructed as a part of the La Costa Town Center project (CT 01-09) to provide
hydromodification flow control for a portion of the La Costa Town Center project and 100-year
storm detention for said project and offsite tributary areas. No changes to the existing detention
basin storage or outflow structure are proposed as part of the La Costa Town Square project. For
both SWMM scenarios, flow duration curves were prepared for POC-1 to determine whether the
proposed Best Management Practice (BMP) is sufficient to meet the current HMP requirements.
The input data required to develop SWMM analyses include rainfall, watershed characteristics,
and BMP configurations. The Oceanside gauge from the Project Clean Water website was used
for this study, since it is the most representative of the site precipitation due to elevation and
proximity to the project site.
La Costa Town Square SWMM Technical Memorandum December 2022
Page 2 of 6 Job # 666-01
Evaporation for the site was modeled using average monthly values from the County hourly
dataset. Surrounding soils for the project site were determined to be type D soils, thus the
predeveloped condition for the site was modeled with Type D hydrologic soils. In existing
conditions, soils are assumed to be uncompacted to represent the current undeveloped
condition of the site. Soils are assumed to be compacted in proposed conditions. Based on the
HMP Review and Analysis prepared for the Cities of San Marcos, Oceanside & Vista2, other SWMM
inputs for the subareas are discussed in the appendices to this document, where the selection of
the parameters is explained in detail.
HMP MODELING
POC-1 is located west of the project, at the outfall where the site currently discharges into the
existing detention basin. In the existing condition, the site drains westerly to POC-1, and
confluences with runoff from the La Costa Town Center project (Project No. CT 01-09) within the
detention basin before entering the MS4. The existing site is in a mass graded state and was
modeled as completely pervious. For simplicity, the existing and proposed condition areas were
assumed equal. In the proposed condition, the developed area tributary to POC-1 is drained to
two proprietary biofiltration systems, and one undisturbed onsite slope area will continue to
discharge directly to the revised basin, with unchanged subcatchment properties. Table 1.1
summarizes data for DMA 1 and the offsite area.
TABLE 1.1 – SUMMARY OF EXISTING AND PROPOSED CONDITIONS FOR POC-1
DMA Tributary Area, A (ac) Impervious Percentage, Ip
DMA EX 4.94 0.0%
DMA PR 81.25%
The proprietary biofiltration systems are responsible for handling hydromodification requirements
for POC-1. Low flows are routed through the proposed biofiltration BMPs, where treated
stormwater runoff is directly discharged to POC-1. The larger of the two biofiltration systems, BMP
2, will feature an oversized influent storm drain designed to detain high flows (i.e., flows
corresponding to all ponded depths exceeding the system operating head) through a flow
control structure located at the west end of the drive aisle.
General Considerations
It is assumed that storm water quality requirements for the project will be met by the proposed
storm water quality facilities. However, detailed water quality requirements are not discussed
within this technical memo. For further information regarding storm water quality requirements for
the project, please refer to the Project Storm Water Management Plan (SWQMP).
BMP MODELING FOR HMP PURPOSES
Modeling HMP BMPs
La Costa Town Square SWMM Technical Memorandum December 2022
Page 3 of 6 Job # 666-01
Two flow-based proprietary biofiltration systems are proposed for hydromodification conformance
for POC-1. Table 2 presents the proposed low-flow dimensions for the proposed proprietary
biofiltration systems. Table 3 presents the high-flow dimensions for the dedicated flow control
structure for hydromodification flow control compliance at POC-1.
TABLE 2 – SUMMARY OF PROPRIETARY BIOFILTRATION BMPs
BMP Model No. Flow Control Riser Orifice Diameter (in)
Low-Flow Orifice Quantity Operating Head (feet)
MWS # 1 MWS-L-8-24-V-HC 4.09 1 4.4
MWS # 2 MWS-L-4-6-C 1.22 1 3.4
TABLE 3 – SUMMARY OF FLOW CONTROL STRUCTURE
Lowest Flow Control Type
Lowest Flow Control Elevation
Mid Flow Control Type
Mid Flow Control Elevation
Highest Flow Control Type
Highest Flow Control Elevation
(1x) 1.5-inch
orifice
4.4 feet above MWS
orifice
(1x) 12-inch wide by 1-
inch high slot
3.17 feet
above orifice
(1x) 4-foot-
wide weir
5.59 feet
above orifice
FLOW DURATION CURVE COMPARISON
Flow Duration Curves (FDC) were compared at the project’s POC by exporting the hourly runoff
time series results from SWMM to a spreadsheet. The FDC was compared between 50% of the
existing condition Q2 up to the existing condition Q10. The Q2 and Q10 were determined with a
partial duration statistical analysis of the runoff time series in an Excel spreadsheet using the
Cunnane plotting position method (which is the preferred plotting methodology in the HMP
Permit). As the SWMM Model includes a statistical analysis based on the Weibull Plotting Position
Method, the Weibull Method was also used within the spreadsheet to ensure that the results were
similar to those obtained by the SWMM Model.
The range from 50% of Q2 up to Q10 was divided into 100 equal time intervals; the number of hours
that each flow rate was exceeded was counted from the hourly series. Additionally, the
intermediate peaks with a return period “i” were obtained (Qi with i=3 to 9). For the purpose of
the plot, the values were presented as percentage of time exceeded for each flow rate. FDC
comparison for POC-1 is illustrated in Figure 1 in both normal and logarithmic scale.
As can be seen in Figure 1, the FDC for the proposed condition with the HMP facilities is within 110%
of the curve for the existing condition in both peak flow and duration. The additional runoff
volume generated from developing the site will be released to the existing curb and gutter system
at a flow rate below the 50% Q2 lower threshold. Additionally, the project will not increase peak
flow rates between the Q2 and the Q10, as shown in the graphics and in the peak flow tables in
Attachment 1.
La Costa Town Square SWMM Technical Memorandum December 2022
Page 4 of 6 Job # 666-01
SUMMARY
This study has demonstrated that the proposed proprietary biofiltration BMPs and flow control
structure provided within the La Costa Town Square project is sufficient to meet the current HMP
criteria at POC-1 if the cross-sectional area and volume recommended within this technical
memorandum, and the respective pump flowrates, are incorporated as specified within the
proposed project site.
La Costa Town Square SWMM Technical Memorandum December 2022
Page 5 of 6 Job # 666-01
KEY ASSUMPTIONS
1. Types D soils are representative of the existing and developed conditions per the SDMBMPDM.
2. The existing and proposed condition drainage areas were taken to be equivalent for
hydromodification flow control purposes.
REFERENCES
[1] – “Model BMP Design Manual San Diego Region – For Permanent Site Design, Storm Water
Treatment, and Hydromodification Management”, June 2015, Geosyntec Consultants & Rick
Engineering Company.
[2] – “Review and Analysis of San Diego County Hydromodification Management Plan (HMP):
Assumptions, Criteria, Methods, & Modeling Tools – Prepared for the Cities of San Marcos,
Oceanside & Vista”, May 2012, Tory R. Walker Engineering.
[3] – Order R9-2013-001, California Regional Water Quality Control Board San Diego Region
(SDRWQCB).
[4] – “Handbook of Hydrology”, David R. Maidment, Editor in Chief. 1992, McGraw Hill.
ATTACHMENTS
1. Q2 to Q10 Comparison Tables
2. FDC Plots (log and natural “x” scale) and Flow Duration Tables.
3. List of the “n” largest Peaks: Pre-Developed and Post-Developed Conditions
4. Elevation vs. Area Curves and Elevation vs. Discharge Curves to be used in SWMM
5. DMA Maps, Project plan and section sketches
6. SWMM Input Data in Input Format (Existing and Developed Models)
7. SWMM Explanation of Significant Variables
8. Soil Map
9. Summary files from the SWMM Model
MWS #1 + FLOW CONTROL STRUCTURE DISCHARGE RATING CURVE
Notes:
Diameter:4.09 inches Quantity:1 Quantity:1 h taken as total depth above the invert of the lowest discharge opening.
Quantity:1 Invert Elevation:7.58ft Invert Elevation:10.00 ft Hw = height of slot/weir invert above basin bottom
Invert Elevation:0.000 ft Width:1.00ft Length:4.00 ft
Type Vertical Height:1.00in Hw:286.86 ft
0.083ft Type Sharp
Hw:284.44ft
Diameter:1.500 inches Quantity:Invert Elevation:ft Basin Footprint:sfQuantity:1 Invert Elevation:ft Length:ft Infiltration Rate in/hrInvert Elevation:4.400 ft Width:ft Breadth:ft Factor of Safety
Height:in Hw:276.86 ft Design Infiltration Rate in/hr
0.000ft Type Sharp
Hw:276.86ft Invert Elevation:276.86 ft
Orifice Discharge Coefficient Orifice Flow Weir Flow Qcontrol (cfs)Orifice Discharge Coefficient Orifice Flow Weir Flow Qcontrol (cfs)Orifice Discharge Coefficient Orifice Flow Weir Discharge Coefficient Weir Flow Qcontrol (cfs)Orifice Discharge Coefficient Orifice Flow Weir Discharge Coefficient Weir Flow Qcontrol (cfs)Weir Discharge Coefficient Q (cfs)Weir Discharge Coefficient Q (cfs)
276.86 0.000 N/A N/A 0.000 0.000 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.000276.90 0.042 N/A N/A 0.003 0.003 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.003276.94 0.083 N/A N/A 0.013 0.013 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.013276.99 0.125 N/A N/A 0.029 0.029 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.029277.03 0.167 N/A N/A 0.050 0.050 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.050277.07 0.208 N/A N/A 0.075 0.075 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.075
277.11 0.250 N/A N/A 0.104 0.104 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.104277.15 0.292 N/A N/A 0.136 0.136 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.136
277.19 0.333 N/A N/A 0.170 0.170 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.170277.24 0.375 0.597 0.198 N/A 0.198 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.198
277.28 0.417 0.597 0.217 N/A 0.217 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.217277.32 0.458 0.597 0.235 N/A 0.235 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.235
277.36 0.500 0.597 0.251 N/A 0.251 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.251277.40 0.542 0.597 0.266 N/A 0.266 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.266
277.44 0.583 0.597 0.281 N/A 0.281 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.281277.49 0.625 0.597 0.295 N/A 0.295 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.295
277.53 0.667 0.597 0.308 N/A 0.308 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.308277.57 0.708 0.597 0.321 N/A 0.321 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.321
277.61 0.750 0.597 0.333 N/A 0.333 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.333277.65 0.792 0.597 0.345 N/A 0.345 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.345
277.69 0.833 0.597 0.356 N/A 0.356 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.356277.74 0.875 0.598 0.368 N/A 0.368 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.368277.78 0.917 0.598 0.378 N/A 0.378 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.378277.82 0.958 0.598 0.389 N/A 0.389 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.389277.86 1.000 0.598 0.399 N/A 0.399 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.399277.90 1.042 0.598 0.409 N/A 0.409 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.409277.94 1.083 0.599 0.419 N/A 0.419 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.419277.99 1.125 0.599 0.428 N/A 0.428 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.428278.03 1.167 0.599 0.438 N/A 0.438 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.438
278.07 1.208 0.599 0.447 N/A 0.447 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.447278.11 1.250 0.599 0.455 N/A 0.455 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.455
278.15 1.292 0.599 0.464 N/A 0.464 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.464278.19 1.333 0.599 0.473 N/A 0.473 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.473
278.24 1.375 0.599 0.481 N/A 0.481 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.481278.28 1.417 0.599 0.489 N/A 0.489 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.489
278.32 1.458 0.599 0.497 N/A 0.497 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.497278.36 1.500 0.599 0.506 N/A 0.506 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.506
278.40 1.542 0.599 0.514 N/A 0.514 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.514278.44 1.583 0.599 0.522 N/A 0.522 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.522
278.49 1.625 0.599 0.529 N/A 0.529 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.529278.53 1.667 0.599 0.537 N/A 0.537 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.537
278.57 1.708 0.599 0.544 N/A 0.544 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.544
LOWER WEIR EMERGENCY WEIR Qinf(cfs)
QTOTAL(cfs)
Infiltration
UPPER SLOTElevation (ft)
Lowest Orifice Lower Slot Lower Weir
Upper Orifice Upper Slot Emergency Weir
Absolute Invert Elevation of Lowest Discharge Opening
h(ft)
LOWEST ORIFICE UPPER ORIFICE LOWER SLOT
0.000
5.000
10.000
15.000
0.000 20.000 40.000 60.000 80.000 100.000 120.000Stage (ft)Discharge (cfs)
Rating Curve
MWS #1 + FLOW CONTROL STRUCTURE DISCHARGE RATING CURVE
Notes:
Diameter:4.09 inches Quantity:1 Quantity:1 h taken as total depth above the invert of the lowest discharge opening.
Quantity:1 Invert Elevation:7.58ft Invert Elevation:10.00 ft Hw = height of slot/weir invert above basin bottom
Invert Elevation:0.000 ft Width:1.00ft Length:4.00 ft
Type Vertical Height:1.00in Hw:286.86 ft
0.083ft Type Sharp
Hw:284.44ft
Diameter:1.500 inches Quantity:Invert Elevation:ft Basin Footprint:sfQuantity:1 Invert Elevation:ft Length:ft Infiltration Rate in/hrInvert Elevation:4.400 ft Width:ft Breadth:ft Factor of Safety
Height:in Hw:276.86 ft Design Infiltration Rate in/hr
0.000ft Type Sharp
Hw:276.86ft Invert Elevation:276.86 ft
Orifice Discharge Coefficient Orifice Flow Weir Flow Qcontrol (cfs)Orifice Discharge Coefficient Orifice Flow Weir Flow Qcontrol (cfs)Orifice Discharge Coefficient Orifice Flow Weir Discharge Coefficient Weir Flow Qcontrol (cfs)Orifice Discharge Coefficient Orifice Flow Weir Discharge Coefficient Weir Flow Qcontrol (cfs)Weir Discharge Coefficient Q (cfs)Weir Discharge Coefficient Q (cfs)
LOWER WEIR EMERGENCY WEIR Qinf(cfs)
QTOTAL(cfs)
Infiltration
UPPER SLOTElevation (ft)
Lowest Orifice Lower Slot Lower Weir
Upper Orifice Upper Slot Emergency Weir
Absolute Invert Elevation of Lowest Discharge Opening
h(ft)
LOWEST ORIFICE UPPER ORIFICE LOWER SLOT
0.000
5.000
10.000
15.000
0.000 20.000 40.000 60.000 80.000 100.000 120.000Stage (ft)Discharge (cfs)
Rating Curve
278.61 1.750 0.599 0.551 N/A 0.551 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.551278.65 1.792 0.599 0.559 N/A 0.559 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.559278.69 1.833 0.599 0.566 N/A 0.566 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.566278.74 1.875 0.599 0.573 N/A 0.573 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.573278.78 1.917 0.599 0.580 N/A 0.580 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.580278.82 1.958 0.599 0.587 N/A 0.587 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.587
278.86 2.000 0.599 0.593 N/A 0.593 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.593278.90 2.042 0.599 0.600 N/A 0.600 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.600
278.94 2.083 0.599 0.607 N/A 0.607 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.607278.99 2.125 0.599 0.613 N/A 0.613 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.613
279.03 2.167 0.599 0.620 N/A 0.620 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.620279.07 2.208 0.599 0.626 N/A 0.626 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.626
279.11 2.250 0.599 0.632 N/A 0.632 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.632279.15 2.292 0.599 0.639 N/A 0.639 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.639
279.19 2.333 0.599 0.645 N/A 0.645 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.645279.24 2.375 0.599 0.651 N/A 0.651 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.651
279.28 2.417 0.599 0.657 N/A 0.657 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.657279.32 2.458 0.599 0.663 N/A 0.663 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.663
279.36 2.500 0.599 0.669 N/A 0.669 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.669279.40 2.542 0.599 0.675 N/A 0.675 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.675
279.44 2.583 0.599 0.681 N/A 0.681 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.681279.49 2.625 0.599 0.687 N/A 0.687 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.687279.53 2.667 0.599 0.693 N/A 0.693 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.693279.57 2.708 0.599 0.699 N/A 0.699 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.699279.61 2.750 0.599 0.704 N/A 0.704 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.704279.65 2.792 0.599 0.710 N/A 0.710 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.710279.69 2.833 0.599 0.716 N/A 0.716 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.716279.74 2.875 0.599 0.721 N/A 0.721 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.721279.78 2.917 0.599 0.727 N/A 0.727 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.727
279.82 2.958 0.599 0.732 N/A 0.732 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.732279.86 3.000 0.599 0.738 N/A 0.738 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.738
279.90 3.042 0.599 0.743 N/A 0.743 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.743279.94 3.083 0.599 0.749 N/A 0.749 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.749
279.99 3.125 0.599 0.754 N/A 0.754 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.754280.03 3.167 0.599 0.759 N/A 0.759 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.759
280.07 3.208 0.599 0.764 N/A 0.764 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.764280.11 3.250 0.599 0.770 N/A 0.770 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.770
280.15 3.292 0.599 0.775 N/A 0.775 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.775280.19 3.333 0.599 0.780 N/A 0.780 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.780
280.24 3.375 0.599 0.785 N/A 0.785 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.785280.28 3.417 0.599 0.790 N/A 0.790 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.790
280.32 3.458 0.599 0.795 N/A 0.795 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.795
MWS #1 + FLOW CONTROL STRUCTURE DISCHARGE RATING CURVE
Notes:
Diameter:4.09 inches Quantity:1 Quantity:1 h taken as total depth above the invert of the lowest discharge opening.
Quantity:1 Invert Elevation:7.58ft Invert Elevation:10.00 ft Hw = height of slot/weir invert above basin bottom
Invert Elevation:0.000 ft Width:1.00ft Length:4.00 ft
Type Vertical Height:1.00in Hw:286.86 ft
0.083ft Type Sharp
Hw:284.44ft
Diameter:1.500 inches Quantity:Invert Elevation:ft Basin Footprint:sfQuantity:1 Invert Elevation:ft Length:ft Infiltration Rate in/hrInvert Elevation:4.400 ft Width:ft Breadth:ft Factor of Safety
Height:in Hw:276.86 ft Design Infiltration Rate in/hr
0.000ft Type Sharp
Hw:276.86ft Invert Elevation:276.86 ft
Orifice Discharge Coefficient Orifice Flow Weir Flow Qcontrol (cfs)Orifice Discharge Coefficient Orifice Flow Weir Flow Qcontrol (cfs)Orifice Discharge Coefficient Orifice Flow Weir Discharge Coefficient Weir Flow Qcontrol (cfs)Orifice Discharge Coefficient Orifice Flow Weir Discharge Coefficient Weir Flow Qcontrol (cfs)Weir Discharge Coefficient Q (cfs)Weir Discharge Coefficient Q (cfs)
LOWER WEIR EMERGENCY WEIR Qinf(cfs)
QTOTAL(cfs)
Infiltration
UPPER SLOTElevation (ft)
Lowest Orifice Lower Slot Lower Weir
Upper Orifice Upper Slot Emergency Weir
Absolute Invert Elevation of Lowest Discharge Opening
h(ft)
LOWEST ORIFICE UPPER ORIFICE LOWER SLOT
0.000
5.000
10.000
15.000
0.000 20.000 40.000 60.000 80.000 100.000 120.000Stage (ft)Discharge (cfs)
Rating Curve
280.36 3.500 0.599 0.800 N/A 0.800 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.800280.40 3.542 0.599 0.805 N/A 0.805 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.805280.44 3.583 0.599 0.810 N/A 0.810 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.810280.49 3.625 0.599 0.815 N/A 0.815 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.815280.53 3.667 0.599 0.820 N/A 0.820 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.820280.57 3.708 0.599 0.825 N/A 0.825 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.825
280.61 3.750 0.599 0.830 N/A 0.830 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.830280.65 3.792 0.599 0.834 N/A 0.834 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.834
280.69 3.833 0.599 0.839 N/A 0.839 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.839280.74 3.875 0.599 0.844 N/A 0.844 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.844
280.78 3.917 0.599 0.848 N/A 0.848 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.848280.82 3.958 0.599 0.853 N/A 0.853 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.853
280.86 4.000 0.599 0.858 N/A 0.858 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.858280.90 4.042 0.599 0.862 N/A 0.862 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.862
280.94 4.083 0.598 0.867 N/A 0.867 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.867280.99 4.125 0.598 0.871 N/A 0.871 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.871
281.03 4.167 0.598 0.876 N/A 0.876 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.876281.07 4.208 0.598 0.880 N/A 0.880 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.880
281.11 4.250 0.598 0.885 N/A 0.885 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.885281.15 4.292 0.598 0.889 N/A 0.889 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.889
281.19 4.333 0.598 0.894 N/A 0.894 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.894281.24 4.375 0.598 0.898 N/A 0.898 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.898281.26 4.400 0.598 0.901 N/A 0.901 N/A N/A 0.000 0.000 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.901281.28 4.417 0.598 0.903 N/A 0.903 N/A N/A 0.000 0.000 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.903281.32 4.458 0.598 0.907 N/A 0.907 N/A N/A 0.004 0.004 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.911281.36 4.500 0.598 0.911 N/A 0.911 N/A N/A 0.010 0.010 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.921281.40 4.542 0.598 0.916 N/A 0.916 0.612 0.017 N/A 0.017 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.933281.44 4.583 0.598 0.920 N/A 0.920 0.612 0.021 N/A 0.021 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.941281.49 4.625 0.598 0.924 N/A 0.924 0.612 0.024 N/A 0.024 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.949
281.53 4.667 0.598 0.929 N/A 0.929 0.612 0.027 N/A 0.027 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.956281.57 4.708 0.598 0.933 N/A 0.933 0.612 0.030 N/A 0.030 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.963
281.61 4.750 0.598 0.937 N/A 0.937 0.612 0.032 N/A 0.032 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.970281.65 4.792 0.598 0.941 N/A 0.941 0.612 0.035 N/A 0.035 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.976
281.69 4.833 0.598 0.946 N/A 0.946 0.612 0.037 N/A 0.037 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.982281.74 4.875 0.598 0.950 N/A 0.950 0.611 0.039 N/A 0.039 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.988
281.78 4.917 0.598 0.954 N/A 0.954 0.611 0.041 N/A 0.041 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 0.995281.82 4.958 0.598 0.958 N/A 0.958 0.611 0.042 N/A 0.042 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.001
281.86 5.000 0.598 0.962 N/A 0.962 0.609 0.044 N/A 0.044 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.006281.90 5.042 0.598 0.966 N/A 0.966 0.609 0.046 N/A 0.046 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.012
281.94 5.083 0.598 0.971 N/A 0.971 0.608 0.047 N/A 0.047 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.018281.99 5.125 0.598 0.975 N/A 0.975 0.608 0.049 N/A 0.049 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.023
282.03 5.167 0.598 0.979 N/A 0.979 0.607 0.050 N/A 0.050 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.029
MWS #1 + FLOW CONTROL STRUCTURE DISCHARGE RATING CURVE
Notes:
Diameter:4.09 inches Quantity:1 Quantity:1 h taken as total depth above the invert of the lowest discharge opening.
Quantity:1 Invert Elevation:7.58ft Invert Elevation:10.00 ft Hw = height of slot/weir invert above basin bottom
Invert Elevation:0.000 ft Width:1.00ft Length:4.00 ft
Type Vertical Height:1.00in Hw:286.86 ft
0.083ft Type Sharp
Hw:284.44ft
Diameter:1.500 inches Quantity:Invert Elevation:ft Basin Footprint:sfQuantity:1 Invert Elevation:ft Length:ft Infiltration Rate in/hrInvert Elevation:4.400 ft Width:ft Breadth:ft Factor of Safety
Height:in Hw:276.86 ft Design Infiltration Rate in/hr
0.000ft Type Sharp
Hw:276.86ft Invert Elevation:276.86 ft
Orifice Discharge Coefficient Orifice Flow Weir Flow Qcontrol (cfs)Orifice Discharge Coefficient Orifice Flow Weir Flow Qcontrol (cfs)Orifice Discharge Coefficient Orifice Flow Weir Discharge Coefficient Weir Flow Qcontrol (cfs)Orifice Discharge Coefficient Orifice Flow Weir Discharge Coefficient Weir Flow Qcontrol (cfs)Weir Discharge Coefficient Q (cfs)Weir Discharge Coefficient Q (cfs)
LOWER WEIR EMERGENCY WEIR Qinf(cfs)
QTOTAL(cfs)
Infiltration
UPPER SLOTElevation (ft)
Lowest Orifice Lower Slot Lower Weir
Upper Orifice Upper Slot Emergency Weir
Absolute Invert Elevation of Lowest Discharge Opening
h(ft)
LOWEST ORIFICE UPPER ORIFICE LOWER SLOT
0.000
5.000
10.000
15.000
0.000 20.000 40.000 60.000 80.000 100.000 120.000Stage (ft)Discharge (cfs)
Rating Curve
282.07 5.208 0.598 0.983 N/A 0.983 0.607 0.052 N/A 0.052 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.034282.11 5.250 0.598 0.987 N/A 0.987 0.607 0.053 N/A 0.053 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.040282.15 5.292 0.598 0.991 N/A 0.991 0.606 0.054 N/A 0.054 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.045282.19 5.333 0.598 0.995 N/A 0.995 0.606 0.056 N/A 0.056 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.051282.24 5.375 0.598 0.999 N/A 0.999 0.605 0.057 N/A 0.057 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.056282.28 5.417 0.598 1.003 N/A 1.003 0.605 0.058 N/A 0.058 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.061
282.32 5.458 0.598 1.007 N/A 1.007 0.605 0.059 N/A 0.059 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.066282.36 5.500 0.598 1.011 N/A 1.011 0.605 0.061 N/A 0.061 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.071
282.40 5.542 0.598 1.015 N/A 1.015 0.605 0.062 N/A 0.062 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.077282.44 5.583 0.598 1.019 N/A 1.019 0.604 0.063 N/A 0.063 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.082
282.49 5.625 0.598 1.023 N/A 1.023 0.604 0.064 N/A 0.064 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.087282.53 5.667 0.598 1.026 N/A 1.026 0.604 0.065 N/A 0.065 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.092
282.57 5.708 0.598 1.030 N/A 1.030 0.604 0.066 N/A 0.066 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.097282.61 5.750 0.598 1.034 N/A 1.034 0.604 0.067 N/A 0.067 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.102
282.65 5.792 0.598 1.038 N/A 1.038 0.603 0.068 N/A 0.068 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.107282.69 5.833 0.598 1.042 N/A 1.042 0.603 0.070 N/A 0.070 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.111
282.74 5.875 0.598 1.046 N/A 1.046 0.603 0.071 N/A 0.071 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.116282.78 5.917 0.598 1.050 N/A 1.050 0.603 0.072 N/A 0.072 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.121
282.82 5.958 0.598 1.053 N/A 1.053 0.603 0.073 N/A 0.073 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.126282.86 6.000 0.598 1.057 N/A 1.057 0.602 0.074 N/A 0.074 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.131
282.90 6.042 0.598 1.061 N/A 1.061 0.602 0.075 N/A 0.075 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.135282.94 6.083 0.598 1.065 N/A 1.065 0.602 0.075 N/A 0.075 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.140282.99 6.125 0.598 1.068 N/A 1.068 0.602 0.076 N/A 0.076 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.145283.03 6.167 0.598 1.072 N/A 1.072 0.602 0.077 N/A 0.077 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.150283.07 6.208 0.598 1.076 N/A 1.076 0.602 0.078 N/A 0.078 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.154283.11 6.250 0.598 1.080 N/A 1.080 0.602 0.079 N/A 0.079 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.159283.15 6.292 0.598 1.083 N/A 1.083 0.602 0.080 N/A 0.080 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.163283.19 6.333 0.598 1.087 N/A 1.087 0.602 0.081 N/A 0.081 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.168283.24 6.375 0.598 1.091 N/A 1.091 0.601 0.082 N/A 0.082 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.173
283.28 6.417 0.598 1.094 N/A 1.094 0.601 0.083 N/A 0.083 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.177283.32 6.458 0.598 1.098 N/A 1.098 0.601 0.084 N/A 0.084 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.182
283.36 6.500 0.598 1.102 N/A 1.102 0.601 0.084 N/A 0.084 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.186283.40 6.542 0.598 1.105 N/A 1.105 0.601 0.085 N/A 0.085 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.190
283.44 6.583 0.598 1.109 N/A 1.109 0.601 0.086 N/A 0.086 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.195283.49 6.625 0.598 1.112 N/A 1.112 0.601 0.087 N/A 0.087 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.199
283.53 6.667 0.598 1.116 N/A 1.116 0.601 0.088 N/A 0.088 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.204283.57 6.708 0.598 1.120 N/A 1.120 0.601 0.089 N/A 0.089 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.208
283.61 6.750 0.598 1.123 N/A 1.123 0.601 0.089 N/A 0.089 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.213283.65 6.792 0.598 1.127 N/A 1.127 0.601 0.090 N/A 0.090 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.217
283.69 6.833 0.598 1.130 N/A 1.130 0.601 0.091 N/A 0.091 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.221283.74 6.875 0.598 1.134 N/A 1.134 0.601 0.092 N/A 0.092 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.226
283.78 6.917 0.598 1.137 N/A 1.137 0.601 0.093 N/A 0.093 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.230
MWS #1 + FLOW CONTROL STRUCTURE DISCHARGE RATING CURVE
Notes:
Diameter:4.09 inches Quantity:1 Quantity:1 h taken as total depth above the invert of the lowest discharge opening.
Quantity:1 Invert Elevation:7.58ft Invert Elevation:10.00 ft Hw = height of slot/weir invert above basin bottom
Invert Elevation:0.000 ft Width:1.00ft Length:4.00 ft
Type Vertical Height:1.00in Hw:286.86 ft
0.083ft Type Sharp
Hw:284.44ft
Diameter:1.500 inches Quantity:Invert Elevation:ft Basin Footprint:sfQuantity:1 Invert Elevation:ft Length:ft Infiltration Rate in/hrInvert Elevation:4.400 ft Width:ft Breadth:ft Factor of Safety
Height:in Hw:276.86 ft Design Infiltration Rate in/hr
0.000ft Type Sharp
Hw:276.86ft Invert Elevation:276.86 ft
Orifice Discharge Coefficient Orifice Flow Weir Flow Qcontrol (cfs)Orifice Discharge Coefficient Orifice Flow Weir Flow Qcontrol (cfs)Orifice Discharge Coefficient Orifice Flow Weir Discharge Coefficient Weir Flow Qcontrol (cfs)Orifice Discharge Coefficient Orifice Flow Weir Discharge Coefficient Weir Flow Qcontrol (cfs)Weir Discharge Coefficient Q (cfs)Weir Discharge Coefficient Q (cfs)
LOWER WEIR EMERGENCY WEIR Qinf(cfs)
QTOTAL(cfs)
Infiltration
UPPER SLOTElevation (ft)
Lowest Orifice Lower Slot Lower Weir
Upper Orifice Upper Slot Emergency Weir
Absolute Invert Elevation of Lowest Discharge Opening
h(ft)
LOWEST ORIFICE UPPER ORIFICE LOWER SLOT
0.000
5.000
10.000
15.000
0.000 20.000 40.000 60.000 80.000 100.000 120.000Stage (ft)Discharge (cfs)
Rating Curve
283.82 6.958 0.598 1.141 N/A 1.141 0.601 0.093 N/A 0.093 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.234283.86 7.000 0.598 1.144 N/A 1.144 0.601 0.094 N/A 0.094 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.238283.90 7.042 0.598 1.148 N/A 1.148 0.601 0.095 N/A 0.095 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.243283.94 7.083 0.598 1.151 N/A 1.151 0.601 0.096 N/A 0.096 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.247283.99 7.125 0.598 1.155 N/A 1.155 0.601 0.097 N/A 0.097 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.251284.03 7.167 0.598 1.158 N/A 1.158 0.601 0.097 N/A 0.097 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.255
284.07 7.208 0.598 1.162 N/A 1.162 0.601 0.098 N/A 0.098 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.260284.11 7.250 0.598 1.165 N/A 1.165 0.601 0.099 N/A 0.099 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.264
284.15 7.292 0.598 1.168 N/A 1.168 0.601 0.100 N/A 0.100 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.268284.19 7.333 0.598 1.172 N/A 1.172 0.601 0.100 N/A 0.100 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.272
284.24 7.375 0.598 1.175 N/A 1.175 0.601 0.101 N/A 0.101 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.276284.28 7.417 0.598 1.178 N/A 1.178 0.601 0.102 N/A 0.102 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.280
284.32 7.458 0.598 1.182 N/A 1.182 0.601 0.102 N/A 0.102 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.284284.36 7.500 0.598 1.185 N/A 1.185 0.601 0.103 N/A 0.103 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.288
284.40 7.542 0.598 1.188 N/A 1.188 0.601 0.104 N/A 0.104 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.292284.44 7.583 0.598 1.192 N/A 1.192 0.601 0.105 N/A 0.105 N/A N/A 3.270 0.000 0.000 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.296
284.49 7.625 0.598 1.195 N/A 1.195 0.601 0.105 N/A 0.105 N/A N/A 3.270 0.028 0.028 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.328284.53 7.667 0.598 1.198 N/A 1.198 0.601 0.106 N/A 0.106 N/A N/A 3.270 0.079 0.079 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.383
284.57 7.708 0.598 1.201 N/A 1.201 0.601 0.107 N/A 0.107 0.626 0.121 N/A N/A 0.121 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.429284.61 7.750 0.598 1.205 N/A 1.205 0.601 0.107 N/A 0.107 0.626 0.148 N/A N/A 0.148 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.460
284.65 7.792 0.598 1.208 N/A 1.208 0.601 0.108 N/A 0.108 0.626 0.171 N/A N/A 0.171 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.487284.69 7.833 0.598 1.211 N/A 1.211 0.601 0.109 N/A 0.109 0.626 0.191 N/A N/A 0.191 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.511284.74 7.875 0.598 1.214 N/A 1.214 0.601 0.109 N/A 0.109 0.626 0.209 N/A N/A 0.209 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.533284.78 7.917 0.598 1.218 N/A 1.218 0.601 0.110 N/A 0.110 0.626 0.226 N/A N/A 0.226 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.554284.82 7.958 0.598 1.221 N/A 1.221 0.601 0.111 N/A 0.111 0.626 0.242 N/A N/A 0.242 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.573284.86 8.000 0.597 1.224 N/A 1.224 0.601 0.111 N/A 0.111 0.626 0.256 N/A N/A 0.256 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.592284.90 8.042 0.597 1.227 N/A 1.227 0.601 0.112 N/A 0.112 0.625 0.270 N/A N/A 0.270 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.609284.94 8.083 0.597 1.230 N/A 1.230 0.601 0.113 N/A 0.113 0.625 0.283 N/A N/A 0.283 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.626284.99 8.125 0.597 1.234 N/A 1.234 0.601 0.113 N/A 0.113 0.624 0.295 N/A N/A 0.295 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.642
285.03 8.167 0.597 1.237 N/A 1.237 0.600 0.114 N/A 0.114 0.624 0.307 N/A N/A 0.307 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.658285.07 8.208 0.597 1.240 N/A 1.240 0.600 0.114 N/A 0.114 0.624 0.319 N/A N/A 0.319 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.673
285.11 8.250 0.597 1.243 N/A 1.243 0.600 0.115 N/A 0.115 0.623 0.329 N/A N/A 0.329 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.688285.15 8.292 0.597 1.246 N/A 1.246 0.600 0.116 N/A 0.116 0.623 0.340 N/A N/A 0.340 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.702
285.19 8.333 0.597 1.249 N/A 1.249 0.600 0.116 N/A 0.116 0.623 0.351 N/A N/A 0.351 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.716285.24 8.375 0.597 1.253 N/A 1.253 0.600 0.117 N/A 0.117 0.623 0.361 N/A N/A 0.361 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.730
285.28 8.417 0.597 1.256 N/A 1.256 0.600 0.118 N/A 0.118 0.623 0.371 N/A N/A 0.371 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.744285.32 8.458 0.597 1.259 N/A 1.259 0.600 0.118 N/A 0.118 0.622 0.380 N/A N/A 0.380 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.757
285.36 8.500 0.597 1.262 N/A 1.262 0.600 0.119 N/A 0.119 0.622 0.389 N/A N/A 0.389 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.770285.40 8.542 0.597 1.265 N/A 1.265 0.600 0.119 N/A 0.119 0.622 0.398 N/A N/A 0.398 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.783
285.44 8.583 0.597 1.268 N/A 1.268 0.600 0.120 N/A 0.120 0.622 0.407 N/A N/A 0.407 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.795285.49 8.625 0.597 1.271 N/A 1.271 0.600 0.121 N/A 0.121 0.622 0.416 N/A N/A 0.416 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.808
285.53 8.667 0.597 1.274 N/A 1.274 0.600 0.121 N/A 0.121 0.622 0.425 N/A N/A 0.425 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.820
MWS #1 + FLOW CONTROL STRUCTURE DISCHARGE RATING CURVE
Notes:
Diameter:4.09 inches Quantity:1 Quantity:1 h taken as total depth above the invert of the lowest discharge opening.
Quantity:1 Invert Elevation:7.58ft Invert Elevation:10.00 ft Hw = height of slot/weir invert above basin bottom
Invert Elevation:0.000 ft Width:1.00ft Length:4.00 ft
Type Vertical Height:1.00in Hw:286.86 ft
0.083ft Type Sharp
Hw:284.44ft
Diameter:1.500 inches Quantity:Invert Elevation:ft Basin Footprint:sfQuantity:1 Invert Elevation:ft Length:ft Infiltration Rate in/hrInvert Elevation:4.400 ft Width:ft Breadth:ft Factor of Safety
Height:in Hw:276.86 ft Design Infiltration Rate in/hr
0.000ft Type Sharp
Hw:276.86ft Invert Elevation:276.86 ft
Orifice Discharge Coefficient Orifice Flow Weir Flow Qcontrol (cfs)Orifice Discharge Coefficient Orifice Flow Weir Flow Qcontrol (cfs)Orifice Discharge Coefficient Orifice Flow Weir Discharge Coefficient Weir Flow Qcontrol (cfs)Orifice Discharge Coefficient Orifice Flow Weir Discharge Coefficient Weir Flow Qcontrol (cfs)Weir Discharge Coefficient Q (cfs)Weir Discharge Coefficient Q (cfs)
LOWER WEIR EMERGENCY WEIR Qinf(cfs)
QTOTAL(cfs)
Infiltration
UPPER SLOTElevation (ft)
Lowest Orifice Lower Slot Lower Weir
Upper Orifice Upper Slot Emergency Weir
Absolute Invert Elevation of Lowest Discharge Opening
h(ft)
LOWEST ORIFICE UPPER ORIFICE LOWER SLOT
0.000
5.000
10.000
15.000
0.000 20.000 40.000 60.000 80.000 100.000 120.000Stage (ft)Discharge (cfs)
Rating Curve
285.57 8.708 0.597 1.278 N/A 1.278 0.600 0.122 N/A 0.122 0.622 0.433 N/A N/A 0.433 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.832285.61 8.750 0.597 1.281 N/A 1.281 0.600 0.122 N/A 0.122 0.622 0.441 N/A N/A 0.441 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.844285.65 8.792 0.597 1.284 N/A 1.284 0.600 0.123 N/A 0.123 0.622 0.449 N/A N/A 0.449 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.856285.69 8.833 0.597 1.287 N/A 1.287 0.600 0.123 N/A 0.123 0.621 0.457 N/A N/A 0.457 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.867285.74 8.875 0.597 1.290 N/A 1.290 0.600 0.124 N/A 0.124 0.621 0.464 N/A N/A 0.464 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.878285.78 8.917 0.597 1.293 N/A 1.293 0.600 0.125 N/A 0.125 0.621 0.472 N/A N/A 0.472 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.890
285.82 8.958 0.597 1.296 N/A 1.296 0.600 0.125 N/A 0.125 0.621 0.479 N/A N/A 0.479 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.901285.86 9.000 0.597 1.299 N/A 1.299 0.599 0.126 N/A 0.126 0.621 0.487 N/A N/A 0.487 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.912
285.90 9.042 0.597 1.302 N/A 1.302 0.599 0.126 N/A 0.126 0.620 0.494 N/A N/A 0.494 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.922285.94 9.083 0.597 1.305 N/A 1.305 0.599 0.127 N/A 0.127 0.620 0.501 N/A N/A 0.501 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.933
285.99 9.125 0.597 1.308 N/A 1.308 0.599 0.127 N/A 0.127 0.620 0.508 N/A N/A 0.508 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.944286.03 9.167 0.597 1.311 N/A 1.311 0.599 0.128 N/A 0.128 0.620 0.515 N/A N/A 0.515 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.954
286.07 9.208 0.597 1.314 N/A 1.314 0.599 0.129 N/A 0.129 0.620 0.522 N/A N/A 0.522 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.964286.11 9.250 0.597 1.317 N/A 1.317 0.599 0.129 N/A 0.129 0.620 0.528 N/A N/A 0.528 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.974
286.15 9.292 0.597 1.320 N/A 1.320 0.599 0.130 N/A 0.130 0.620 0.535 N/A N/A 0.535 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.985286.19 9.333 0.597 1.323 N/A 1.323 0.599 0.130 N/A 0.130 0.619 0.541 N/A N/A 0.541 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 1.995
286.24 9.375 0.597 1.326 N/A 1.326 0.599 0.131 N/A 0.131 0.619 0.548 N/A N/A 0.548 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 2.005286.28 9.417 0.597 1.329 N/A 1.329 0.599 0.131 N/A 0.131 0.619 0.554 N/A N/A 0.554 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 2.015
286.32 9.458 0.597 1.332 N/A 1.332 0.599 0.132 N/A 0.132 0.619 0.561 N/A N/A 0.561 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 2.025286.36 9.500 0.597 1.335 N/A 1.335 0.599 0.132 N/A 0.132 0.619 0.567 N/A N/A 0.567 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 2.035
286.40 9.542 0.597 1.338 N/A 1.338 0.599 0.133 N/A 0.133 0.619 0.573 N/A N/A 0.573 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 2.044286.44 9.583 0.597 1.341 N/A 1.341 0.599 0.133 N/A 0.133 0.619 0.579 N/A N/A 0.579 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 2.054286.49 9.625 0.597 1.344 N/A 1.344 0.599 0.134 N/A 0.134 0.619 0.585 N/A N/A 0.585 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 2.064286.53 9.667 0.597 1.347 N/A 1.347 0.599 0.135 N/A 0.135 0.619 0.591 N/A N/A 0.591 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 2.073286.57 9.708 0.597 1.350 N/A 1.350 0.599 0.135 N/A 0.135 0.619 0.597 N/A N/A 0.597 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 2.083286.61 9.750 0.597 1.353 N/A 1.353 0.599 0.136 N/A 0.136 0.619 0.603 N/A N/A 0.603 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 2.092286.65 9.792 0.597 1.356 N/A 1.356 0.599 0.136 N/A 0.136 0.619 0.609 N/A N/A 0.609 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 2.101286.69 9.833 0.597 1.359 N/A 1.359 0.599 0.137 N/A 0.137 0.618 0.614 N/A N/A 0.614 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 2.110286.74 9.875 0.597 1.362 N/A 1.362 0.599 0.137 N/A 0.137 0.618 0.620 N/A N/A 0.620 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 2.119
286.78 9.917 0.597 1.365 N/A 1.365 0.599 0.138 N/A 0.138 0.618 0.626 N/A N/A 0.626 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 2.128286.82 9.958 0.597 1.368 N/A 1.368 0.599 0.138 N/A 0.138 0.618 0.631 N/A N/A 0.631 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 2.137
286.86 10.000 0.597 1.370 N/A 1.370 0.599 0.139 N/A 0.139 0.618 0.637 N/A N/A 0.637 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 2.146286.90 10.042 0.597 1.373 N/A 1.373 0.599 0.139 N/A 0.139 0.617 0.642 N/A N/A 0.642 N/A N/A N/A N/A N/A 3.270 0.111 N/A N/A N/A 2.266
286.94 10.083 0.597 1.376 N/A 1.376 0.599 0.140 N/A 0.140 0.617 0.647 N/A N/A 0.647 N/A N/A N/A N/A N/A 3.270 0.315 N/A N/A N/A 2.478286.99 10.125 0.597 1.379 N/A 1.379 0.599 0.140 N/A 0.140 0.617 0.653 N/A N/A 0.653 N/A N/A N/A N/A N/A 3.270 0.578 N/A N/A N/A 2.750
287.03 10.167 0.597 1.382 N/A 1.382 0.599 0.141 N/A 0.141 0.617 0.658 N/A N/A 0.658 N/A N/A N/A N/A N/A 3.270 0.890 N/A N/A N/A 3.071287.07 10.208 0.597 1.385 N/A 1.385 0.599 0.141 N/A 0.141 0.617 0.663 N/A N/A 0.663 N/A N/A N/A N/A N/A 3.270 1.244 N/A N/A N/A 3.433
287.11 10.250 0.597 1.388 N/A 1.388 0.599 0.142 N/A 0.142 0.617 0.668 N/A N/A 0.668 N/A N/A N/A N/A N/A 3.270 1.635 N/A N/A N/A 3.833287.15 10.292 0.597 1.391 N/A 1.391 0.599 0.142 N/A 0.142 0.617 0.674 N/A N/A 0.674 N/A N/A N/A N/A N/A 3.270 2.061 N/A N/A N/A 4.267
287.19 10.333 0.597 1.393 N/A 1.393 0.599 0.143 N/A 0.143 0.617 0.679 N/A N/A 0.679 N/A N/A N/A N/A N/A 3.270 2.518 N/A N/A N/A 4.733287.24 10.375 0.597 1.396 N/A 1.396 0.599 0.143 N/A 0.143 0.617 0.684 N/A N/A 0.684 N/A N/A N/A N/A N/A 3.271 3.004 N/A N/A N/A 5.228
287.28 10.417 0.597 1.399 N/A 1.399 0.599 0.144 N/A 0.144 0.617 0.689 N/A N/A 0.689 N/A N/A N/A N/A N/A 3.271 3.519 N/A N/A N/A 5.751
MWS #1 + FLOW CONTROL STRUCTURE DISCHARGE RATING CURVE
Notes:
Diameter:4.09 inches Quantity:1 Quantity:1 h taken as total depth above the invert of the lowest discharge opening.
Quantity:1 Invert Elevation:7.58ft Invert Elevation:10.00 ft Hw = height of slot/weir invert above basin bottom
Invert Elevation:0.000 ft Width:1.00ft Length:4.00 ft
Type Vertical Height:1.00in Hw:286.86 ft
0.083ft Type Sharp
Hw:284.44ft
Diameter:1.500 inches Quantity:Invert Elevation:ft Basin Footprint:sfQuantity:1 Invert Elevation:ft Length:ft Infiltration Rate in/hrInvert Elevation:4.400 ft Width:ft Breadth:ft Factor of Safety
Height:in Hw:276.86 ft Design Infiltration Rate in/hr
0.000ft Type Sharp
Hw:276.86ft Invert Elevation:276.86 ft
Orifice Discharge Coefficient Orifice Flow Weir Flow Qcontrol (cfs)Orifice Discharge Coefficient Orifice Flow Weir Flow Qcontrol (cfs)Orifice Discharge Coefficient Orifice Flow Weir Discharge Coefficient Weir Flow Qcontrol (cfs)Orifice Discharge Coefficient Orifice Flow Weir Discharge Coefficient Weir Flow Qcontrol (cfs)Weir Discharge Coefficient Q (cfs)Weir Discharge Coefficient Q (cfs)
LOWER WEIR EMERGENCY WEIR Qinf(cfs)
QTOTAL(cfs)
Infiltration
UPPER SLOTElevation (ft)
Lowest Orifice Lower Slot Lower Weir
Upper Orifice Upper Slot Emergency Weir
Absolute Invert Elevation of Lowest Discharge Opening
h(ft)
LOWEST ORIFICE UPPER ORIFICE LOWER SLOT
0.000
5.000
10.000
15.000
0.000 20.000 40.000 60.000 80.000 100.000 120.000Stage (ft)Discharge (cfs)
Rating Curve
287.32 10.458 0.597 1.402 N/A 1.402 0.599 0.144 N/A 0.144 0.617 0.694 N/A N/A 0.694 N/A N/A N/A N/A N/A 3.271 4.059 N/A N/A N/A 6.300287.36 10.500 0.597 1.405 N/A 1.405 0.599 0.145 N/A 0.145 0.617 0.699 N/A N/A 0.699 N/A N/A N/A N/A N/A 3.271 4.625 N/A N/A N/A 6.874287.40 10.542 0.597 1.408 N/A 1.408 0.599 0.145 N/A 0.145 0.616 0.704 N/A N/A 0.704 N/A N/A N/A N/A N/A 3.271 5.216 N/A N/A N/A 7.473287.44 10.583 0.597 1.411 N/A 1.411 0.599 0.146 N/A 0.146 0.616 0.709 N/A N/A 0.709 N/A N/A N/A N/A N/A 3.271 5.829 N/A N/A N/A 8.094287.49 10.625 0.597 1.413 N/A 1.413 0.599 0.146 N/A 0.146 0.616 0.714 N/A N/A 0.714 N/A N/A N/A N/A N/A 3.271 6.465 N/A N/A N/A 8.738287.53 10.667 0.597 1.416 N/A 1.416 0.599 0.147 N/A 0.147 0.616 0.718 N/A N/A 0.718 N/A N/A N/A N/A N/A 3.271 7.122 N/A N/A N/A 9.403
287.57 10.708 0.597 1.419 N/A 1.419 0.599 0.147 N/A 0.147 0.616 0.723 N/A N/A 0.723 N/A N/A N/A N/A N/A 3.271 7.800 N/A N/A N/A 10.090287.61 10.750 0.597 1.422 N/A 1.422 0.599 0.148 N/A 0.148 0.616 0.728 N/A N/A 0.728 N/A N/A N/A N/A N/A 3.271 8.498 N/A N/A N/A 10.796
287.65 10.792 0.597 1.425 N/A 1.425 0.599 0.148 N/A 0.148 0.616 0.733 N/A N/A 0.733 N/A N/A N/A N/A N/A 3.271 9.217 N/A N/A N/A 11.522287.69 10.833 0.597 1.427 N/A 1.427 0.599 0.149 N/A 0.149 0.616 0.737 N/A N/A 0.737 N/A N/A N/A N/A N/A 3.271 9.954 N/A N/A N/A 12.267
287.74 10.875 0.597 1.430 N/A 1.430 0.599 0.149 N/A 0.149 0.616 0.742 N/A N/A 0.742 N/A N/A N/A N/A N/A 3.271 10.710 N/A N/A N/A 13.031287.78 10.917 0.597 1.433 N/A 1.433 0.599 0.150 N/A 0.150 0.616 0.747 N/A N/A 0.747 N/A N/A N/A N/A N/A 3.271 11.484 N/A N/A N/A 13.814
287.82 10.958 0.597 1.436 N/A 1.436 0.599 0.150 N/A 0.150 0.615 0.751 N/A N/A 0.751 N/A N/A N/A N/A N/A 3.271 12.276 N/A N/A N/A 14.614287.86 11.000 0.597 1.438 N/A 1.438 0.599 0.151 N/A 0.151 0.615 0.756 N/A N/A 0.756 N/A N/A N/A N/A N/A 3.271 13.086 N/A N/A N/A 15.431
287.90 11.042 0.597 1.441 N/A 1.441 0.599 0.151 N/A 0.151 0.615 0.760 N/A N/A 0.760 N/A N/A N/A N/A N/A 3.271 13.912 N/A N/A N/A 16.265287.94 11.083 0.597 1.444 N/A 1.444 0.599 0.152 N/A 0.152 0.615 0.765 N/A N/A 0.765 N/A N/A N/A N/A N/A 3.272 14.755 N/A N/A N/A 17.116
287.99 11.125 0.597 1.447 N/A 1.447 0.599 0.152 N/A 0.152 0.615 0.770 N/A N/A 0.770 N/A N/A N/A N/A N/A 3.272 15.615 N/A N/A N/A 17.984288.03 11.167 0.597 1.449 N/A 1.449 0.599 0.153 N/A 0.153 0.615 0.774 N/A N/A 0.774 N/A N/A N/A N/A N/A 3.272 16.491 N/A N/A N/A 18.867
288.07 11.208 0.597 1.452 N/A 1.452 0.599 0.153 N/A 0.153 0.615 0.779 N/A N/A 0.779 N/A N/A N/A N/A N/A 3.272 17.382 N/A N/A N/A 19.766288.11 11.250 0.597 1.455 N/A 1.455 0.599 0.154 N/A 0.154 0.615 0.783 N/A N/A 0.783 N/A N/A N/A N/A N/A 3.272 18.290 N/A N/A N/A 20.681
288.15 11.292 0.597 1.458 N/A 1.458 0.599 0.154 N/A 0.154 0.615 0.787 N/A N/A 0.787 N/A N/A N/A N/A N/A 3.272 19.212 N/A N/A N/A 21.611288.19 11.333 0.597 1.460 N/A 1.460 0.599 0.155 N/A 0.155 0.615 0.791 N/A N/A 0.791 N/A N/A N/A N/A N/A 3.272 20.149 N/A N/A N/A 22.556288.24 11.375 0.597 1.463 N/A 1.463 0.599 0.155 N/A 0.155 0.615 0.796 N/A N/A 0.796 N/A N/A N/A N/A N/A 3.272 21.102 N/A N/A N/A 23.516288.28 11.417 0.597 1.466 N/A 1.466 0.599 0.156 N/A 0.156 0.615 0.800 N/A N/A 0.800 N/A N/A N/A N/A N/A 3.272 22.068 N/A N/A N/A 24.490288.32 11.458 0.597 1.469 N/A 1.469 0.599 0.156 N/A 0.156 0.614 0.804 N/A N/A 0.804 N/A N/A N/A N/A N/A 3.272 23.050 N/A N/A N/A 25.479288.36 11.500 0.597 1.471 N/A 1.471 0.599 0.156 N/A 0.156 0.614 0.809 N/A N/A 0.809 N/A N/A N/A N/A N/A 3.272 24.045 N/A N/A N/A 26.481288.40 11.542 0.597 1.474 N/A 1.474 0.599 0.157 N/A 0.157 0.614 0.813 N/A N/A 0.813 N/A N/A N/A N/A N/A 3.272 25.054 N/A N/A N/A 27.498288.44 11.583 0.597 1.477 N/A 1.477 0.599 0.157 N/A 0.157 0.614 0.817 N/A N/A 0.817 N/A N/A N/A N/A N/A 3.272 26.077 N/A N/A N/A 28.528288.49 11.625 0.597 1.479 N/A 1.479 0.599 0.158 N/A 0.158 0.614 0.821 N/A N/A 0.821 N/A N/A N/A N/A N/A 3.272 27.114 N/A N/A N/A 29.572
288.53 11.667 0.597 1.482 N/A 1.482 0.599 0.158 N/A 0.158 0.614 0.825 N/A N/A 0.825 N/A N/A N/A N/A N/A 3.272 28.164 N/A N/A N/A 30.630288.57 11.708 0.597 1.485 N/A 1.485 0.599 0.159 N/A 0.159 0.614 0.830 N/A N/A 0.830 N/A N/A N/A N/A N/A 3.272 29.227 N/A N/A N/A 31.700
288.61 11.750 0.597 1.487 N/A 1.487 0.599 0.159 N/A 0.159 0.614 0.834 N/A N/A 0.834 N/A N/A N/A N/A N/A 3.272 30.303 N/A N/A N/A 32.784288.65 11.792 0.597 1.490 N/A 1.490 0.599 0.160 N/A 0.160 0.614 0.838 N/A N/A 0.838 N/A N/A N/A N/A N/A 3.272 31.392 N/A N/A N/A 33.880
288.69 11.833 0.597 1.493 N/A 1.493 0.599 0.160 N/A 0.160 0.614 0.842 N/A N/A 0.842 N/A N/A N/A N/A N/A 3.273 32.494 N/A N/A N/A 34.989288.74 11.875 0.597 1.495 N/A 1.495 0.599 0.161 N/A 0.161 0.614 0.846 N/A N/A 0.846 N/A N/A N/A N/A N/A 3.273 33.609 N/A N/A N/A 36.111
288.78 11.917 0.597 1.498 N/A 1.498 0.599 0.161 N/A 0.161 0.614 0.850 N/A N/A 0.850 N/A N/A N/A N/A N/A 3.273 34.736 N/A N/A N/A 37.245288.82 11.958 0.597 1.501 N/A 1.501 0.599 0.161 N/A 0.161 0.613 0.854 N/A N/A 0.854 N/A N/A N/A N/A N/A 3.273 35.876 N/A N/A N/A 38.392
288.86 12.000 0.597 1.503 N/A 1.503 0.599 0.162 N/A 0.162 0.613 0.858 N/A N/A 0.858 N/A N/A N/A N/A N/A 3.273 37.027 N/A N/A N/A 39.551288.90 12.042 0.597 1.506 N/A 1.506 0.599 0.162 N/A 0.162 0.613 0.862 N/A N/A 0.862 N/A N/A N/A N/A N/A 3.273 38.191 N/A N/A N/A 40.721
288.94 12.083 0.597 1.509 N/A 1.509 0.599 0.163 N/A 0.163 0.613 0.866 N/A N/A 0.866 N/A N/A N/A N/A N/A 3.273 39.367 N/A N/A N/A 41.904288.99 12.125 0.597 1.511 N/A 1.511 0.599 0.163 N/A 0.163 0.613 0.870 N/A N/A 0.870 N/A N/A N/A N/A N/A 3.273 40.555 N/A N/A N/A 43.099
289.03 12.167 0.597 1.514 N/A 1.514 0.599 0.164 N/A 0.164 0.613 0.874 N/A N/A 0.874 N/A N/A N/A N/A N/A 3.273 41.754 N/A N/A N/A 44.305
MWS #1 + FLOW CONTROL STRUCTURE DISCHARGE RATING CURVE
Notes:
Diameter:4.09 inches Quantity:1 Quantity:1 h taken as total depth above the invert of the lowest discharge opening.
Quantity:1 Invert Elevation:7.58ft Invert Elevation:10.00 ft Hw = height of slot/weir invert above basin bottom
Invert Elevation:0.000 ft Width:1.00ft Length:4.00 ft
Type Vertical Height:1.00in Hw:286.86 ft
0.083ft Type Sharp
Hw:284.44ft
Diameter:1.500 inches Quantity:Invert Elevation:ft Basin Footprint:sfQuantity:1 Invert Elevation:ft Length:ft Infiltration Rate in/hrInvert Elevation:4.400 ft Width:ft Breadth:ft Factor of Safety
Height:in Hw:276.86 ft Design Infiltration Rate in/hr
0.000ft Type Sharp
Hw:276.86ft Invert Elevation:276.86 ft
Orifice Discharge Coefficient Orifice Flow Weir Flow Qcontrol (cfs)Orifice Discharge Coefficient Orifice Flow Weir Flow Qcontrol (cfs)Orifice Discharge Coefficient Orifice Flow Weir Discharge Coefficient Weir Flow Qcontrol (cfs)Orifice Discharge Coefficient Orifice Flow Weir Discharge Coefficient Weir Flow Qcontrol (cfs)Weir Discharge Coefficient Q (cfs)Weir Discharge Coefficient Q (cfs)
LOWER WEIR EMERGENCY WEIR Qinf(cfs)
QTOTAL(cfs)
Infiltration
UPPER SLOTElevation (ft)
Lowest Orifice Lower Slot Lower Weir
Upper Orifice Upper Slot Emergency Weir
Absolute Invert Elevation of Lowest Discharge Opening
h(ft)
LOWEST ORIFICE UPPER ORIFICE LOWER SLOT
0.000
5.000
10.000
15.000
0.000 20.000 40.000 60.000 80.000 100.000 120.000Stage (ft)Discharge (cfs)
Rating Curve
289.07 12.208 0.597 1.517 N/A 1.517 0.599 0.164 N/A 0.164 0.613 0.878 N/A N/A 0.878 N/A N/A N/A N/A N/A 3.273 42.965 N/A N/A N/A 45.523289.11 12.250 0.597 1.519 N/A 1.519 0.599 0.165 N/A 0.165 0.613 0.881 N/A N/A 0.881 N/A N/A N/A N/A N/A 3.273 44.187 N/A N/A N/A 46.752289.15 12.292 0.597 1.522 N/A 1.522 0.599 0.165 N/A 0.165 0.613 0.885 N/A N/A 0.885 N/A N/A N/A N/A N/A 3.273 45.421 N/A N/A N/A 47.993289.19 12.333 0.597 1.524 N/A 1.524 0.599 0.165 N/A 0.165 0.613 0.889 N/A N/A 0.889 N/A N/A N/A N/A N/A 3.273 46.666 N/A N/A N/A 49.245289.24 12.375 0.597 1.527 N/A 1.527 0.599 0.166 N/A 0.166 0.613 0.893 N/A N/A 0.893 N/A N/A N/A N/A N/A 3.273 47.923 N/A N/A N/A 50.509289.28 12.417 0.597 1.530 N/A 1.530 0.599 0.166 N/A 0.166 0.613 0.897 N/A N/A 0.897 N/A N/A N/A N/A N/A 3.273 49.190 N/A N/A N/A 51.783
289.32 12.458 0.597 1.532 N/A 1.532 0.599 0.167 N/A 0.167 0.612 0.900 N/A N/A 0.900 N/A N/A N/A N/A N/A 3.273 50.469 N/A N/A N/A 53.068289.36 12.500 0.597 1.535 N/A 1.535 0.599 0.167 N/A 0.167 0.612 0.904 N/A N/A 0.904 N/A N/A N/A N/A N/A 3.273 51.758 N/A N/A N/A 54.365
289.40 12.542 0.597 1.537 N/A 1.537 0.599 0.168 N/A 0.168 0.612 0.908 N/A N/A 0.908 N/A N/A N/A N/A N/A 3.274 53.059 N/A N/A N/A 55.672289.44 12.583 0.597 1.540 N/A 1.540 0.599 0.168 N/A 0.168 0.612 0.912 N/A N/A 0.912 N/A N/A N/A N/A N/A 3.274 54.370 N/A N/A N/A 56.989
289.49 12.625 0.597 1.543 N/A 1.543 0.599 0.168 N/A 0.168 0.612 0.915 N/A N/A 0.915 N/A N/A N/A N/A N/A 3.274 55.691 N/A N/A N/A 58.318289.53 12.667 0.597 1.545 N/A 1.545 0.599 0.169 N/A 0.169 0.612 0.919 N/A N/A 0.919 N/A N/A N/A N/A N/A 3.274 57.024 N/A N/A N/A 59.657
289.57 12.708 0.597 1.548 N/A 1.548 0.599 0.169 N/A 0.169 0.612 0.923 N/A N/A 0.923 N/A N/A N/A N/A N/A 3.274 58.366 N/A N/A N/A 61.006289.61 12.750 0.597 1.550 N/A 1.550 0.599 0.170 N/A 0.170 0.612 0.926 N/A N/A 0.926 N/A N/A N/A N/A N/A 3.274 59.719 N/A N/A N/A 62.366
289.65 12.792 0.597 1.553 N/A 1.553 0.599 0.170 N/A 0.170 0.612 0.930 N/A N/A 0.930 N/A N/A N/A N/A N/A 3.274 61.083 N/A N/A N/A 63.736289.69 12.833 0.597 1.555 N/A 1.555 0.599 0.171 N/A 0.171 0.612 0.933 N/A N/A 0.933 N/A N/A N/A N/A N/A 3.274 62.457 N/A N/A N/A 65.116
289.74 12.875 0.597 1.558 N/A 1.558 0.599 0.171 N/A 0.171 0.612 0.937 N/A N/A 0.937 N/A N/A N/A N/A N/A 3.274 63.841 N/A N/A N/A 66.507289.78 12.917 0.597 1.561 N/A 1.561 0.599 0.171 N/A 0.171 0.612 0.941 N/A N/A 0.941 N/A N/A N/A N/A N/A 3.274 65.235 N/A N/A N/A 67.907
289.82 12.958 0.597 1.563 N/A 1.563 0.599 0.172 N/A 0.172 0.611 0.944 N/A N/A 0.944 N/A N/A N/A N/A N/A 3.274 66.639 N/A N/A N/A 69.318289.86 13.000 0.597 1.566 N/A 1.566 0.599 0.172 N/A 0.172 0.611 0.948 N/A N/A 0.948 N/A N/A N/A N/A N/A 3.274 68.053 N/A N/A N/A 70.739
289.90 13.042 0.597 1.568 N/A 1.568 0.599 0.173 N/A 0.173 0.611 0.951 N/A N/A 0.951 N/A N/A N/A N/A N/A 3.274 69.477 N/A N/A N/A 72.169289.94 13.083 0.597 1.571 N/A 1.571 0.599 0.173 N/A 0.173 0.611 0.955 N/A N/A 0.955 N/A N/A N/A N/A N/A 3.274 70.910 N/A N/A N/A 73.609289.99 13.125 0.597 1.573 N/A 1.573 0.599 0.174 N/A 0.174 0.611 0.959 N/A N/A 0.959 N/A N/A N/A N/A N/A 3.274 72.354 N/A N/A N/A 75.059290.03 13.167 0.597 1.576 N/A 1.576 0.599 0.174 N/A 0.174 0.611 0.962 N/A N/A 0.962 N/A N/A N/A N/A N/A 3.274 73.807 N/A N/A N/A 76.519290.07 13.208 0.597 1.578 N/A 1.578 0.599 0.174 N/A 0.174 0.611 0.965 N/A N/A 0.965 N/A N/A N/A N/A N/A 3.274 75.270 N/A N/A N/A 77.988290.11 13.250 0.597 1.581 N/A 1.581 0.599 0.175 N/A 0.175 0.611 0.969 N/A N/A 0.969 N/A N/A N/A N/A N/A 3.275 76.742 N/A N/A N/A 79.467290.15 13.292 0.597 1.583 N/A 1.583 0.599 0.175 N/A 0.175 0.611 0.972 N/A N/A 0.972 N/A N/A N/A N/A N/A 3.275 78.224 N/A N/A N/A 80.955290.19 13.333 0.597 1.586 N/A 1.586 0.599 0.176 N/A 0.176 0.611 0.976 N/A N/A 0.976 N/A N/A N/A N/A N/A 3.275 79.715 N/A N/A N/A 82.453290.24 13.375 0.597 1.588 N/A 1.588 0.599 0.176 N/A 0.176 0.611 0.979 N/A N/A 0.979 N/A N/A N/A N/A N/A 3.275 81.216 N/A N/A N/A 83.960
290.28 13.417 0.597 1.591 N/A 1.591 0.599 0.176 N/A 0.176 0.611 0.983 N/A N/A 0.983 N/A N/A N/A N/A N/A 3.275 82.726 N/A N/A N/A 85.476290.32 13.458 0.597 1.593 N/A 1.593 0.599 0.177 N/A 0.177 0.610 0.986 N/A N/A 0.986 N/A N/A N/A N/A N/A 3.275 84.246 N/A N/A N/A 87.002
290.36 13.500 0.597 1.596 N/A 1.596 0.599 0.177 N/A 0.177 0.610 0.989 N/A N/A 0.989 N/A N/A N/A N/A N/A 3.275 85.774 N/A N/A N/A 88.537290.40 13.542 0.597 1.598 N/A 1.598 0.599 0.178 N/A 0.178 0.610 0.993 N/A N/A 0.993 N/A N/A N/A N/A N/A 3.275 87.312 N/A N/A N/A 90.081
290.44 13.583 0.597 1.601 N/A 1.601 0.599 0.178 N/A 0.178 0.610 0.996 N/A N/A 0.996 N/A N/A N/A N/A N/A 3.275 88.859 N/A N/A N/A 91.634290.49 13.625 0.597 1.603 N/A 1.603 0.599 0.178 N/A 0.178 0.610 1.000 N/A N/A 1.000 N/A N/A N/A N/A N/A 3.275 90.415 N/A N/A N/A 93.196
290.53 13.667 0.597 1.606 N/A 1.606 0.599 0.179 N/A 0.179 0.610 1.003 N/A N/A 1.003 N/A N/A N/A N/A N/A 3.275 91.980 N/A N/A N/A 94.767290.57 13.708 0.597 1.608 N/A 1.608 0.599 0.179 N/A 0.179 0.610 1.006 N/A N/A 1.006 N/A N/A N/A N/A N/A 3.275 93.554 N/A N/A N/A 96.348
290.61 13.750 0.597 1.611 N/A 1.611 0.599 0.180 N/A 0.180 0.610 1.009 N/A N/A 1.009 N/A N/A N/A N/A N/A 3.275 95.137 N/A N/A N/A 97.937290.65 13.792 0.597 1.613 N/A 1.613 0.599 0.180 N/A 0.180 0.610 1.013 N/A N/A 1.013 N/A N/A N/A N/A N/A 3.275 96.729 N/A N/A N/A 99.535
290.69 13.833 0.597 1.616 N/A 1.616 0.599 0.180 N/A 0.180 0.610 1.016 N/A N/A 1.016 N/A N/A N/A N/A N/A 3.275 98.329 N/A N/A N/A 101.141290.74 13.875 0.597 1.618 N/A 1.618 0.598 0.181 N/A 0.181 0.610 1.020 N/A N/A 1.020 N/A N/A N/A N/A N/A 3.275 99.938 N/A N/A N/A 102.757
290.78 13.917 0.597 1.621 N/A 1.621 0.598 0.181 N/A 0.181 0.610 1.023 N/A N/A 1.023 N/A N/A N/A N/A N/A 3.275 101.556 N/A N/A N/A 104.381
MWS #1 + FLOW CONTROL STRUCTURE DISCHARGE RATING CURVE
Notes:
Diameter:4.09 inches Quantity:1 Quantity:1 h taken as total depth above the invert of the lowest discharge opening.
Quantity:1 Invert Elevation:7.58ft Invert Elevation:10.00 ft Hw = height of slot/weir invert above basin bottom
Invert Elevation:0.000 ft Width:1.00ft Length:4.00 ft
Type Vertical Height:1.00in Hw:286.86 ft
0.083ft Type Sharp
Hw:284.44ft
Diameter:1.500 inches Quantity:Invert Elevation:ft Basin Footprint:sfQuantity:1 Invert Elevation:ft Length:ft Infiltration Rate in/hrInvert Elevation:4.400 ft Width:ft Breadth:ft Factor of Safety
Height:in Hw:276.86 ft Design Infiltration Rate in/hr
0.000ft Type Sharp
Hw:276.86ft Invert Elevation:276.86 ft
Orifice Discharge Coefficient Orifice Flow Weir Flow Qcontrol (cfs)Orifice Discharge Coefficient Orifice Flow Weir Flow Qcontrol (cfs)Orifice Discharge Coefficient Orifice Flow Weir Discharge Coefficient Weir Flow Qcontrol (cfs)Orifice Discharge Coefficient Orifice Flow Weir Discharge Coefficient Weir Flow Qcontrol (cfs)Weir Discharge Coefficient Q (cfs)Weir Discharge Coefficient Q (cfs)
LOWER WEIR EMERGENCY WEIR Qinf(cfs)
QTOTAL(cfs)
Infiltration
UPPER SLOTElevation (ft)
Lowest Orifice Lower Slot Lower Weir
Upper Orifice Upper Slot Emergency Weir
Absolute Invert Elevation of Lowest Discharge Opening
h(ft)
LOWEST ORIFICE UPPER ORIFICE LOWER SLOT
0.000
5.000
10.000
15.000
0.000 20.000 40.000 60.000 80.000 100.000 120.000Stage (ft)Discharge (cfs)
Rating Curve
290.82 13.958 0.597 1.623 N/A 1.623 0.598 0.182 N/A 0.182 0.610 1.026 N/A N/A 1.026 N/A N/A N/A N/A N/A 3.276 103.183 N/A N/A N/A 106.014290.86 14.000 0.597 1.626 N/A 1.626 0.598 0.182 N/A 0.182 0.610 1.029 N/A N/A 1.029 N/A N/A N/A N/A N/A 3.276 104.818 N/A N/A N/A 107.655290.90 14.042 0.597 1.628 N/A 1.628 0.598 0.182 N/A 0.182 0.610 1.033 N/A N/A 1.033 N/A N/A N/A N/A N/A 3.276 106.462 N/A N/A N/A 109.305290.94 14.083 0.597 1.630 N/A 1.630 0.598 0.183 N/A 0.183 0.610 1.036 N/A N/A 1.036 N/A N/A N/A N/A N/A 3.276 108.115 N/A N/A N/A 110.964291.00 14.140 0.597 1.634 N/A 1.634 0.598 0.183 N/A 0.183 0.610 1.040 N/A N/A 1.040 N/A N/A N/A N/A N/A 3.276 110.376 N/A N/A N/A 113.233
HY-8 Culvert Analysis Report
Crossing Discharge Data
Discharge Selection Method: Specify Minimum, Design, and Maximum Flow
Minimum Flow: 16.4 cfs
Design Flow: 16.4 cfs
Maximum Flow: 16.4 cfs
Table 1 - Summary of Culvert Flows at Crossing: Single 30
Headwater Elevation
(ft)
Total Discharge (cfs)Single 30 Discharge
(cfs)
Roadway Discharge
(cfs)
Iterations
288.31 16.40 16.40 0.00 1
288.31 16.40 16.40 0.00 1
288.31 16.40 16.40 0.00 1
288.31 16.40 16.40 0.00 1
288.31 16.40 16.40 0.00 1
288.31 16.40 16.40 0.00 1
288.31 16.40 16.40 0.00 1
288.31 16.40 16.40 0.00 1
288.31 16.40 16.40 0.00 1
288.31 16.40 16.40 0.00 1
288.31 16.40 16.40 0.00 1
290.00 28.31 28.31 0.00 Overtopping
Rating Curve Plot for Crossing: Single 30
Table 2 - Culvert Summary Table: Single 30
Total
Discharge
(cfs)
Culvert
Discharge
(cfs)
Headwater
Elevation (ft)
Inlet Control
Depth (ft)
Outlet
Control
Depth (ft)
Flow
Type
Normal
Depth (ft)
Critical
Depth (ft)
Outlet Depth
(ft)
Tailwater
Depth (ft)
Outlet
Velocity
(ft/s)
Tailwater
Velocity
(ft/s)
16.40 16.40 288.31 2.048 7.043 4-FFf 1.599 1.368 2.500 7.146 3.341 0.000
16.40 16.40 288.31 2.048 7.043 4-FFf 1.599 1.368 2.500 7.146 3.341 0.000
16.40 16.40 288.31 2.048 7.043 4-FFf 1.599 1.368 2.500 7.146 3.341 0.000
16.40 16.40 288.31 2.048 7.043 4-FFf 1.599 1.368 2.500 7.146 3.341 0.000
16.40 16.40 288.31 2.048 7.043 4-FFf 1.599 1.368 2.500 7.146 3.341 0.000
16.40 16.40 288.31 2.048 7.043 4-FFf 1.599 1.368 2.500 7.146 3.341 0.000
16.40 16.40 288.31 2.048 7.043 4-FFf 1.599 1.368 2.500 7.146 3.341 0.000
16.40 16.40 288.31 2.048 7.043 4-FFf 1.599 1.368 2.500 7.146 3.341 0.000
16.40 16.40 288.31 2.048 7.043 4-FFf 1.599 1.368 2.500 7.146 3.341 0.000
16.40 16.40 288.31 2.048 7.043 4-FFf 1.599 1.368 2.500 7.146 3.341 0.000
16.40 16.40 288.31 2.048 7.043 4-FFf 1.599 1.368 2.500 7.146 3.341 0.000
********************************************************************************
Straight Culvert
Inlet Elevation (invert): 281.27 ft, Outlet Elevation (invert): 280.67 ft
Culvert Length: 241.45 ft, Culvert Slope: 0.0025
********************************************************************************
Culvert Performance Curve Plot: Single 30
Water Surface Profile Plot for Culvert: Single 30
Site Data - Single 30
Site Data Option: Culvert Invert Data
Inlet Station: 1302.45 ft
Inlet Elevation: 281.27 ft
Outlet Station: 1061.00 ft
Outlet Elevation: 280.67 ft
Number of Barrels: 1
Culvert Data Summary - Single 30
Barrel Shape: Circular
Barrel Diameter: 2.50 ft
Barrel Material: Smooth HDPE
Embedment: 0.00 in
Barrel Manning's n: 0.0120
Culvert Type: Straight
Inlet Configuration: Square Edge with Headwall
Inlet Depression: None
Table 3 - Downstream Channel Rating Curve (Crossing: Single 30)
Flow (cfs)Water Surface Elev (ft)Depth (ft)Velocity (ft/s)
0.00 281.26 281.26 0.00
0.01 281.36 281.36 0.00
0.02 281.46 281.46 0.00
0.03 281.56 281.56 0.00
0.04 281.65 281.65 0.00
0.04 281.75 281.75 0.00
0.04 281.85 281.85 0.00
0.05 281.95 281.95 0.00
0.05 282.05 282.05 0.00
0.05 282.15 282.15 0.00
0.06 282.24 282.24 0.00
0.06 282.34 282.34 0.00
0.06 282.44 282.44 0.00
0.07 282.54 282.54 0.00
0.07 282.64 282.64 0.00
0.07 282.74 282.74 0.00
0.07 282.83 282.83 0.00
0.07 282.93 282.93 0.00
0.08 283.03 283.03 0.00
0.08 283.13 283.13 0.00
0.08 283.23 283.23 0.00
0.08 283.33 283.33 0.00
0.09 283.42 283.42 0.00
0.09 283.52 283.52 0.00
0.09 283.62 283.62 0.00
0.09 283.72 283.72 0.00
0.09 283.82 283.82 0.00
0.10 283.92 283.92 0.00
0.10 284.01 284.01 0.00
0.10 284.11 284.11 0.00
0.10 284.21 284.21 0.00
0.10 284.31 284.31 0.00
0.10 284.41 284.41 0.00
0.16 284.51 284.51 0.00
0.25 284.61 284.61 0.00
0.30 284.70 284.70 0.00
0.35 284.80 284.80 0.00
0.38 284.90 284.90 0.00
0.41 285.00 285.00 0.00
0.44 285.10 285.10 0.00
0.47 285.20 285.20 0.00
0.49 285.29 285.29 0.00
0.52 285.39 285.39 0.00
0.54 285.49 285.49 0.00
0.56 285.59 285.59 0.00
0.58 285.69 285.69 0.00
0.60 285.79 285.79 0.00
0.62 285.88 285.88 0.00
0.64 285.98 285.98 0.00
0.65 286.08 286.08 0.00
0.67 286.18 286.18 0.00
0.69 286.28 286.28 0.00
0.70 286.38 286.38 0.00
0.72 286.47 286.47 0.00
0.73 286.57 286.57 0.00
0.95 286.67 286.67 0.00
1.60 286.77 286.77 0.00
2.49 286.87 286.87 0.00
3.57 286.97 286.97 0.00
4.82 287.06 287.06 0.00
6.20 287.16 287.16 0.00
7.71 287.26 287.26 0.00
9.34 287.36 287.36 0.00
11.08 287.46 287.46 0.00
12.92 287.56 287.56 0.00
14.86 287.65 287.65 0.00
16.89 287.75 287.75 0.00
19.01 287.85 287.85 0.00
21.22 287.95 287.95 0.00
23.51 288.05 288.05 0.00
25.88 288.15 288.15 0.00
28.32 288.25 288.25 0.00
30.84 288.34 288.34 0.00
33.43 288.44 288.44 0.00
36.10 288.54 288.54 0.00
38.83 288.64 288.64 0.00
41.62 288.74 288.74 0.00
44.49 288.84 288.84 0.00
47.41 288.93 288.93 0.00
50.40 289.03 289.03 0.00
53.45 289.13 289.13 0.00
56.56 289.23 289.23 0.00
59.73 289.33 289.33 0.00
62.96 289.43 289.43 0.00
66.24 289.52 289.52 0.00
69.58 289.62 289.62 0.00
72.97 289.72 289.72 0.00
76.42 289.82 289.82 0.00
79.92 289.92 289.92 0.00
83.48 290.02 290.02 0.00
87.09 290.11 290.11 0.00
90.74 290.21 290.21 0.00
94.45 290.31 290.31 0.00
98.21 290.41 290.41 0.00
102.01 290.51 290.51 0.00
105.87 290.61 290.61 0.00
109.77 290.70 290.70 0.00
113.72 290.80 290.80 0.00
117.72 290.90 290.90 0.00
121.76 291.00 291.00 0.00
Tailwater Channel Data - Single 30
Tailwater Channel Option: Enter Rating Curve
Channel Invert Elevation: 280.58 ft
Roadway Data for Crossing: Single 30
Roadway Profile Shape: Constant Roadway Elevation
Crest Length: 2.00 ft
Crest Elevation: 290.00 ft
Roadway Surface: Paved
Roadway Top Width: 20.00 ft
D:\76882 La Costa Town Square\13 Reports\Hydrology\La Costa, Drainage Study 2022 0210.docx
APPENDIX
County of San Diego Hydrology Manual Excerpts
City of Carlsbad Standards
San Diego County Hydrology Manual
Date: June 2003
SECTION3
Section:
Page:
RATIONAL METHOD AND MODIFIED RATIONAL METHOD
3.1 THERATIONALMETHOD
3
I of26
The Rational Method (RM) is a mathematical formula used to determine the maximum
runoff rate from a given rainfall. It has particular application in urban storm drainage, where
it is used to estimate peak runoff rates from sma11 urban and rural watersheds for the design
of storm drains and small drainage structures. The RM is recommended for analyzing the
runoff response from drainage areas up to approximately 1 square mile in size. It should not
be used in instances where there is a junction of independent drainage systems or for
drainage areas greater than approximately I square mile in size. In these instances, the
Modified Rational Method (MRM) should be used for junctions of independent drainage
systems in watersheds up to approximately I square mile in size (see Section 3.4); or the
NRCS Hydrologic Method should be used for watersheds greater than approximately I
square mile in size (see Section 4).
The RM can be applied using any design storm frequency ( e.g., 100-year, 50-year, I 0-year,
etc.). The local agency determines the design storm frequency that must be used based on
the type of project and specific local requirements. A discussion of design storm frequency
is provided in Section 2.3 of this manual. A procedure has been developed that converts the
6-hour and 24-hour precipitation isopluvial map data to an Intensity-Dmation curve that can
be used for the rainfall intensity in the RM formula as shown in Figure 3-1. The RM is
applicable to a 6-hour storm duration because the procedure uses Intensity-Duration Design
Charts that are based on a 6-hour storm duration.
3.1.1 Rational Method Formula
The RM formula estimates the peak rate of runoff at any location in a watershed as a function
of the drainage area (A), runoff coefficient (C), and rainfall intensity (I) for a dmation equal
to the time of concentration (Tc), which is the time required for water to
3-1
10.0
9.0
8.0
7.0
6.0
5.0
4.0
3.0
2.0
~-
" a ~ '" " ~
, I
IIlIIIIIl ~ [1 I ll1]UI 1mm j i l I lllllllllllllllllllllill l
i I
I
'I
111111111111111111:
EQUATION
= 7.44 P6 D-0.645
= Intensity (in/hr)
, 6-Hour Precipitation (in)
~ , Duration (min)
~'+r'-H-Httttfltlrntfflmtti+tttttl'l-!!:m-H±ll!~
' I L ,. ' ., ..... ;:tt-tl-t-tfi'-lacrl+Httt-ffltttA'i-!::Hftttt tillll 1 [I l:till I llll111 mffi 11
!llllll ■r111
It I
t!ltllt
<;>
l
"' iF
g1.o
~0.9
"· 6.0""E. I I I I , 5.5 §:
20.8 1 1 ,! I I I I I I _ 5.0 Ii""
~0.7 . . . . . . . .. IIIJIIII N-J II 11
0.01 I I I I I I I I I I I " ----_ --
ocl I I I I I I I I I I I I lllllllllllllllll!IIIIIIIIIIIIIJH
11: I I I
I !1 II I .. --
1 !IIJ _____ .. ___ _
. I I
lJ
~
l
oA~ ! l ! ! 1 ! ! t ! .................... , !-+-l-+-l-++-1-+-1-+1-+++l++l-H-H+H+H-H-HHlH-+H-H-++H+lttfttl1Kltlt!l!lt+t+lffi-M++ .. -.. . .. . .. .. , -:: [
I
03
1 i I i 111 ! I I I I I I I 111111111111111!11111111 ! 111 !Ill ;-;--; ,----,. ' ' ' ' Q.2t l ' ' ' ' .
I • ' ' ' ' ' " ' ' ' • I • . ' ' I I J I
H ' ' --' I
I I I I I I
I I ' I
I I I I I I
I I I I I I I I I
o.1' I ! I . . I I I I I I I
5 6 7 8 9 10 15 20 30 40 50
Minutes
Duration
= =
;Jin: :n:11::1 :
!fl/H ! ' I
' ' I
I I ' I l I I
111111 I I
mil I
111111 I I
-i
!
' I I
I
2
~ 2.0
± . .----.---r-!--~ 1.5
' f
' ' ' ' ' ' ' I I I '-111 I I
1.0
'I I I
'I I
11 I I
11 I ' I I I
3 4 5 6
Hours
Intensity-Duration Design Chart• Template
Directions for Application:
(1) From precipitation maps determine 6 hr and 24 hr amounts
for the selected frequency. These maps are included in the
County Hydrology Manual (10, 50, and 100yr maps included
in the Design and Procedure Manual).
(2) Adjust 6 hr precipitation (if necessary) so that it Is within
the range of 45% to 65% of the 24 hr precipitation (not
applicap!e to Desert).
(3) Plot 6 hr precipitation on the right side of the chart.
{4) Draw a line through the point parallel to the plotted lines.
(5) This line is the intensity-duration curve for the location
being analyzed.
Application Form:
(a) Selected frequency ___ year
p
(b) Ps= ___ in .• p24 = ---•p 6 = ___ %(2J
24
(c) Adjusted p6(2) = ___ in.
(d) 1x = __ min.
(e) I= ___ in./hr.
Note: This chart replaces the Intensity-Duration-Frequency
curves used since 1965.
P6
Dura-lion I -------,
7 -10
I 15 20
25
30
' 40
L---: ·-120
' 150
fao
240
~3()0
.. 360
1.5 2 -•-2.5 3 3;5 . 4 4.5 5 5.5 6
t . I I . l . .,. J I ·c· I J I !
2.6:f-3.95•5.27 6.59 7.90 9.22:10.54 11.86 13.17 1'4.49 15.81
·212 -3.18:4.24. 5.30.6.36.7.42: 8.48. 9.54 ·10.60·11.66·12.72
.f68 ~2.ss:3,37' 421 ·5_05·5_90'. 6.74. 7.58. 8.42, 9.27 ·10.11
1_30··-1.9!:r2.sg··-3_2:c 3.s9 -4.s4~ s.19 ··s.84 ··--6.49 • 7_ 13 · 1.1s ·1:-mc· ;-.s2-2,s--·2.ss·•-3_2s ·3.-n·: 4.31 ·-4.a5 · s.se •-s.ocf ~eAS·
_0.93 ~1.40: 1.a1: 2.33 :2.ao :·327~·3_73~20·:-4.67:··s.13: s.eo
0.83 1.24 1.66 2.07 2.49 2.90' 3.32 3.73 4.15 4.56 4.98
_0.69 >03~ 1.38: 1.72: 2.01:2.4( 2.76 : 3.10: 3.45: 3.79 : 4.13
0.60 o.so, 1.19 1.49 1.79 2.09 2.39 2.69 2.98 3.28 3.58
o.53 :o.ao: 1.06: 1.33 ~-1.sg: 1·.as: 2.12 · ·2.39 : 2.s5 · 2.92 : 3.18
0.41 0.61 0.82 1.02 1.23 1.43 1.63 1.84 2.04 2.25 2.45
o:34 ;o:s,:o.ss:o.as·1.02·1.rn· 1.36 · 1_53. 1.10· 1.87. 2.04
o.29 '.o.44'.o..se:0_73·0.ss·1.03' us· 1..32 · 1.47 · 1.s2 · 1.15 ·o:2s···;·o.3s•o·.s2-o.6s·•·ii78 ~-0.91. i04 . 1. 18 . 1.31 . 1.44 . ;·:57
g_.~~ :o.3s_o.43;0.s4:·o.ss:o.i'.6~_0.a1. o.98: 1.os~ 1-=19 · 1.so
0.19 0.28 0.38: 0.47 0.56 0.66 0.75 0.85 0.94 1.03 U3
0.11 ;o.2S:o:ss:·o.42·:_o.so:o.sa· o.67 · o)s·· 0.84 · ci.92 · 1.00
FIGURE ~
San Diego County Hydrology Manual
Date: June 2003
Section:
Page:
3
3 of26
flow from the most remote point of the basin to the location being analyzed. The RM
formula is expressed as follows:
Where:
Q=CIA
Q peak discharge, in cubic feet per second ( cfs)
C runoff coefficient, proportion of the rainfall that runs off the surface (no
units)
I = average rainfall intensity for a duration equal to the Tc for the area, in
inches per hour (Note: If the computed Tc is less than 5 minutes, use 5
minutes for computing the peak discharge, Q)
A = drainage area contributing to the design location, in acres
Combining the units for the expression CIA yields:
(
lacrexinch) (43,560ft') ( !foot ) ( !hour ) ⇒ l.00Scfs
hour acre 12 inches 3,600 seconds
For practical purposes the unit conversion coefficient difference of 0.8% can be ignored.
The RM formula is based on the assumption that for constant rainfall intensity, the peak
discharge rate at a point will occur when the raindrop that falls at the most upstream point in
the tributary drainage basin arrives at the point of interest.
Unlike the MRM (discussed in Section 3.4) or the NRCS hydrologic method (discussed in
Section 4), the RM does not create hydrographs and therefore does not add separate subarea
hydrographs at collection points. Instead, the RM develops peak discharges in the main line
by increasing the Tc as flow travels downstream.
Characteristics of, or assumptions inherent to, the RM are listed below:
• The discharge flow rate resulting from any I is maximum when the I lasts as long as or
longer than the Tc•
3-3
San Diego County Hydrology Manual
Date: June 2003
Section:
Page:
• The storm frequency of peak discharges is the same as that ofI for the given T 0.
3
4 of26
• The fraction of rainfall that becomes runoff ( or the runoff coefficient, C) is independent
of I or precipitation zone number (PZN) condition (PZN Condition is discussed in
Section 4.1.2.4).
• The peak rate of runoff is the only information produced by using the RM.
3.1.2 Runoff Coefficient
Table 3-1 lists the estimated runoff coefficients for urban areas. The concepts related to the
runoff coefficient were evaluated in a report entitled Evaluation, Rational Method "C"
Values (Hill, 2002) that was reviewed by the Hydrology Manual Committee. The Report is
available at San Diego Com1ty Department of Public Works, Flood Control Section and on
the San Diego County Department of Public Works web page.
The runoff coefficients are based on land use and soil type. Soil type can be determined from
the soil type map provided in Appendix A. An appropriate runoff coefficient (C) for each
type of land use in the subarea should be selected from this table and multiplied by the
percentage of the total area (A) included in that class. The sum of the products for all land
uses is the weighted runoff coefficient (E[ CA]). Good engineering judgment should be used
when applying the values presented in Table 3-1, as adjustments to these values may be
appropriate based on site-specific characteristics. In any event, the impervious percentage
(% Impervious) as given in the table, for any area, shall govern the selected value for C. The
runoff coefficient can also be calculated for an area based on soil type and impervious
percentage using the following formula:
3-4
San Diego County Hydrology Manual
Date: June 2003
Section:
Page:
3
5 of26
Where:
C = 0.90 x (%Impervious)+ Cp x (1 - % Impervious)
Cp = Pervious Coefficient Runoff Value for the soil type (shown in
Table 3-1 as Undisturbed Natural Terrain/Permanent Open Space,
0% Impervious). Soil type can be determined from the soil type map
provided in Appendix A.
The values in Table 3-1 are typical for most urban areas. However, if the basin contains rural
or agricultural land use, parks, golf courses, or other types of nonurban land use that are
expected to be permanent, the appropriate value should be selected based upon the soil and
cover and approved by the local agency.
3-5
San Diego County Hydrology Manual
Date: June 2003
Table 3-1
Section:
Page:
RUNOFF COEFFICIENTS FOR URBAN AREAS
Land Use Runoff Coefficient "C"
Soil TYEe
NRCS Elements Coun Elements %IMPER. A B
Undisturbed Natural Terrain (Natural) Permanent Open Space O* 0.20 0.25
Low Density Residential (LDR) Residential, 1.0 DU/A or less 10 0.27 0.32
Low Density Residential (LDR) Residential, 2.0 DU/A or less 20 0.34 0.38
Low Density Residential (LDR) Residential, 2.9 DU/A or less 25 0.38 0.41
Medinm Density Residential (MDR) Residential, 4.3 DU/A or less 30 0.41 0.45
Medinm Density Residential (MDR) Residential, 7 .3 DU/ A or less 40 0.48 0.51
Medinm Density Residential (MDR) Residential, 10.9 DU/A or less 45 0.52 0.54
Medinm Density Residential (MDR) Residential, 14.5 DU/A or less 50 0.55 0.58
Higb Density Residential (HDR) Residential, 24.0 DU/ A or less 65 0.66 0.67
Higb Density Residential (HDR) Residential, 43.0 DU/A or less 80 0.76 0.77
Commercial/Industrial (N. Com) Neighborhood Commercial 80 0.76 0.77
Commercial/Industrial (G. Com) General Commercial 85 0.80 0.80
Commercial/Industrial (O.P. Com) Office Professional/Commercial 90 0.83 0.84
Commercial/Industrial (Limited I.) Limited Industrial 90 0.83 0.84
Commercial/Industrial (General I.) General Industrial 95 0.87 0.87
C
0.30
0.36
0.42
0.45
0.48
0.54
0.57
0.60
0.69
0.78
0.78
0.81
0.84
0.84
0.87
3
6 of26
D
0.35
0.41
0.46
0.49
0.52
0.57
0.60
0.63
0.71
0.79
0.79
0.82
0.85
0.85
0.87
*The values associated with 0% impervious may be used for direct calculation of the runoff coefficient as described in Section 3.1.2 (representing the pervious runoff
coefficient, Cp, for the soil type), or for areas that will remain undisturbed in perpetuity. Justification must be given that the area will remain natural forever ( e.g., the area
is located in Cleveland National Forest).
DU/ A~ dwelling units per acre
NRCS ~ National Resources Conservation Service
3-6
San Diego County Hydrology Manual
Date: June 2003
3.1.3 Rainfall Intensity
Section:
Page:
3
7 of26
The rainfall intensity (I) is the rainfall in inches per hour (in/hr) for a duration equal to the Tc
for a selected storm frequency. Once a paiiicular storm frequency has been selected for
design and a Tc calculated for the drainage area, the rainfall intensity can be determined from
the Intensity-Duration Design Chart (Figure 3-1). The 6-hour storm rainfall amount (P6) and
the 24-hour storm rainfall amount (P24) for the selected storm frequency are also needed for
calculation of I. P6 and P24 can be read from the isopluvial maps provided in Appendix B.
An Intensity-Duration Design Chaii applicable to all areas within San Diego County is
provided as Figure 3-1. Figure 3-2 provides an example of use of the Intensity-Duration
Design Chart. Intensity can also be calculated using the following equation:
I= 7.44 p6 D"o.645
Where: adjusted 6-hour storm rainfall amount (see discussion below)
D duration in minutes (use Tc)
Note: This equation applies only to the 6-hour storm rainfall ainount (i.e., P6 cannot be
changed to P24 to calculate a 24-hour intensity using this equation).
The Intensity-Duration Design Chart and the equation are for the 6-hour storm rainfall
amount. In general, P6 for the selected frequency should be between 45% and 65% of P24 for
the selected frequency. If P6 is not within 45% to 65% of P24, P6 should be increased or
decreased as necessary to meet this criteria. The isopluvial lines are based on precipitation
gauge data. At the time that the isopluvial lines were created, the majority of precipitation
gauges in San Diego County were read daily, and these readings yielded 24-hour
precipitation data. Some 6-hour data were available from the few recording gauges
distributed throughout the County at that time; however, some 6-hour data were extrapolated.
Therefore, the 24-hour precipitation data for San Diego County are considered to be more
reliable.
3-7
1002.95.156.92.957.6410.0 .,.__ ....._ r d . 9-0 "'-1"' !"'-l.: '--1 ~ ... "1_ ! I ! ! I i 11 I i I I I I I I ! JI I I I i 111 i I ! a.o 7' 7'1 ~ ;--, J-, ! Ii I I I I I I 11 ! I 1 ll I I i 11 i ! Ii 7.0N. ,.._ t'-.~'~N. ... ~r,!', l iii I Ii ! I l 111 l l ' I I 11 11·11 I: [ I :-,.J "'I ! " I ~ to, • I ' ' 6.0N I 1' .. , "-.~~" "?-, >"" .. ~• !!I 1! ! ! I l l EQUATION J I " I I J. t-,....._ I ~ l'i... ... :--. t8-l : I : 11 i I = 7 44 Pe o-D.645 ! 5.0 ,,._ f' ,....., ~ ' " • NJ_ 1 ~ ! I I , I . . ! :--,. 1 I" ! ' ! '-i.. ~~ i· Hif:'1 'j ~ 1!i : 1 11 I = Intensity (in/hr) i ,ii. ~• ~ ' ! ) I P 4.0 N-J.... 1'l. N--1• ... I ~ , '. 'i 1 ~ 1 l' I ! I ! 6 = 6-Hour Precipitation (in) N. j r--l "'3.2 in/hr ",. ~1 ~.; l N Jrm:.: 1 ! lJ'i I I I D "" Duration {.min} f f' ~ l i r.. , i N irtts + I .,_ ~ I i '" 30 I I i'-' ! f'-i ! I 1" 11+~ I KJ:i, rf'!-0 ~ ~ ! I !Iii II I I ! I i i I i · 1 r .J I Jr" ~ ~~J i@1~N1 \ ~~, 111i1 i1111 , 1 1· 1· 1' 1· . ~ ,! ,iL . .,d~rHJ_jlJ! t i!( 111 ' ~ I ij IHllll!II 1'1'_1 · ·1•"'i-1 ... ,.!',~ ~1 'I· 1+~J 1™1:11 Jrij~~ rm j•'-h 111 11 i 11 f I 1',.. -;... ~ <I I '' Ii ' ' . '' '' • ; : ': ' I 2.0 I i .. i i .. q l . K-U. I ·•al ,1, 1'i l~fN.. ... ~ : i • I I I "~ ~~ !i I~ ili1 i' U.L j !H~ .... ! ..... lN!'i-.. ',,I: I '" .. ,. n~~ 1 11ir 111 ~~. rm. 1J 'tl#1mt r-h.J'I i ~~ 11 i 1 1. 1 I • -.. . ..... , .• 'lj I ,;:-;-.. ! l j i"N ! I 111! -t ! 11~ I 7' l'1 i"i-. ' 1"N,.! I I I :, ...... N{. l i1 Ii 11'--.! I I! ' I, I I ,. I i ! • I"~ I L!"'l-~ I'" I . a i"'III ~ I r"1ii, ., ; i: 1 ~ · ·) i 1 i ' : l 1' : i i • 1 t t i I ',,,,, II i ~I 11,,, i11 l~~rr--dtm~~1ill:IH J.LJ . ~1-0 1 , · ~ 1 Ii! r :1n~ 11111 · NI '",-.JT-KJ mt~,: s:s i ? I 0 C: ~ i0·9 ! I I !l ~, l iii I I ~ illlil ! : J I l'N I 1'i-. 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I ! ! ! l ! 1 1 i 1 1 111 , , 111111 rn irrn 111 q 1 1 1 q : 1 1 1 ! m 111n111111111 i I I ; 1 1 1 1 I 1 ! , 1 i ! 11 i H p w 11~ 5 6 r as 10 15 20 30 Minutes 40 50 Duration 2 3 Hours 4 5 6 Intensity-Duration Design Chart -Example Directions for Application: {1) From precipitation maps determine 6 hr and 24 hr amounts for the selected frequency. These maps are included in the County Hydrology Manual (10, 50, and 100 yr maps incruded in the Design and Procedure Manual). (2) Adjust 6 hr precipitation (if necessary) so that it is within the range of 45% to 65% of the 24 hr precipitation (not applicap!e to Desert). (3} Plot 6 hr precipitation on the right side of the chart. (4) Draw a line through the point parallel to the plotted lines. {5) This line is the intensity-duration curve for the location being analyzed. Application Form: (a) Selected frequency ___ year p (b) p6 = --in., P24 = ---'P 6 = ___ %{2} 24 (c) Adjusted P6<2)"' ___ in . (d} tx = __ min. (e} I :::, ~--in./hr. Note: This chart replaces the Intensity-Duration-Frequency cunres used slnce 1965. P6 l 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 Duration ! I I I l I [ I l I I ~-5 2.63 3.95 5.27 6.59 7.90 9.22 10.54 11.86 13.17 14.49 15.81 7 -2.12-•s.1a: ,t24 · 5.30 · 6.36 ·7_42' S.48 · 9.54 10.60: 11.s6·12.72 . 10 • 1'i1f·2:53: 3.37. 4.21 -5.05. 5.00 6.74 . 7.58 . 8.4:2 . 9.:27 . 10.11 15 uo ·1.ss·2.sil-3.2,:rs:39· 4_54·5~1g··s.a4~5~49-7_ fa. 7.78 20 T6a-1.62·2:1s··2~iss · 323 ·s:n· 4.31 · 4.as · s.39 •-s.ss ·-6.46 zs 093 1.40:1.a1-2.ss·2.aifs:n--::i.fa-~f2.n--4.67-s.13 -5.so 30 0.83 1.:24: 1.66' 2.07 -2.49 2.90. 3.32. 3.73 . 4.15. 4.56 . 4.98 40 ·o.69 ·1.03· 1.3a· 1.12 2.01·2.41 · 2.76 · 3.10 · 3_45 · 3.79 · 4_13 so o.so ·o.so·1.1s·vm·1.1s·2.09· z.39 · 2.ss · 2.9a · 3.28: 3.58 oo o.53 ·o.ao_1_0o_1_33·1.59·1.oo· 2.12· 2.39 · 2.65· 2.92 · 3_1a _ .. _so .. 0:41 ·0.£1 · o.a:f 1.02 · 1.2s· 1_43· 1.63 · 1.84 2.04 • 2.:25 · 2.45 ---rzo 0.34 o.s(o.68·0.ils'i.0£1~1,," 1.36. 1.53 --1.70. 1.87. 2.04 150 0.29 :0.4.f 0.59; 0.73. 0.88: 1.03. us 1.32 . 1.47 . 1.62 . 1.76 ·-1ao 0.2s :oj9:o.s2~0:ss-oini"o.s1·ul4 -ua · 1.s1 · 1.44: 1.s, ---2,io 0.22 ·o:,fa~o::is·o.54 ·o.ss:o.1s· o.87 · o.ss-· 1.os ·us· ,.3o -300 ·o.1a ,o.2a-ojs· o.41··0:s6·0)5s" o.7s · o.ss · o.94 · 1.ro · ·1.13 · 360 · 0.17 ; 025 · o.33 · 0.42 • o.so · o.sa-o.67 · 0.75 · o.84 -0.92 · 1.00 IF I~-~R El
San Diego County Hydrology Manual
Date: June 2003
Section:
Page:
3
II of26
The sheet flow that is predicted by the FAA equation is limited to conditions that are similar
to runway topography. Some considerations that limit the extent to which the FAA equation
applies are identified below:
• Urban Areas -This "runway type" runoff includes:
1) Flat roofs, sloping at 1 % ±
2) Parking lots at the extreme upstream dtainage basin boundary (at the "ridge" of a
catchment area).
Even a parking lot is limited in the amounts of sheet flow. Parked or moving
vehicles would "break-up" the sheet flow, concentrating runoff into streams that
are not characteristic of sheet flow.
3) Driveways are constructed at the upstream end of catchment areas in some
developments. However, if flow from a roof is directed to a dtiveway through
a downspout or other conveyance mechanism, flow would be concentrated.
4) Flat slopes are prone to meandering flow that tends to be disrupted by minor
in-egularities and obstructions. Maximum Overland Flow lengths are shorter
for the flatter slopes (see Table 3-2).
• Rural or Natural Areas -The FAA equation is applicable to these conditions since
(.5% to 10%) slopes that are uniform in width of flow have slow velocities consistent
with the equation. In-egularities in ten-ain limit the length of application.
1) Most hills and ridge lines have a relatively flat area near the dtainage divide.
However, with flat slopes of .5% ±, minor irregularities would cause flow to
concentrate into streams.
2) Parks, lawns and other vegetated areas would have slow velocities that are
consistent with the FAA Equation.
The concepts related to the initial time of concentration were evaluated in a report entitled
Initial Time of Concentration, Analysis of Parameters (Hill, 2002) that was reviewed by the
Hydrology Manual Committee. The Report is available at San Diego County Department of
Public Works, Flood Control Section and on the San Diego County Department of Public
Works web page.
3-11
San Diego County Hydrology Manual
Date: June 2003
Section:
Page:
3
12 of26
Note that the Initial Time of Concentration should be reflective of the general land-use at the
upstream end of a drainage basin. A single lot with an area of two or less acres does not have
a significant effect where the drainage basin area is 20 to 600 acres.
Table 3-2 provides limits of the length (Maximum Length (LM)) of sheet flow to be used in
hydrology studies. Initial Ti values based on average C values for the Land Use Element are
also included. These values can be used in planning and design applications as described
below. Exceptions may be approved by the "Regulating Agency" when submitted with a
detailed study.
Table 3-2
MAXIMUM OVERLAND FLOW LENGTH (LM)
& INITIAL TIME OF CONCENTRATION (T;)
Element* DU/ .5% 1% 2% 3% 5% 10%
Acre LM Ti LM Ti LM Ti LM T; LM T; LM T;
Natural 50 13.2 70 12.5 85 10.9 100 10.3 100 8.7 100 6.9
LDR 1 50 12.2 70 11.5 85 10.0 100 9.5 100 8.0 100 6.4
LDR 2 50 11.3 70 10.5 85 9.2 100 8.8 100 7.4 100 5.8
LDR 2.9 50 10.7 70 10.0 85 8.8 95 8.1 100 7.0 100 5.6
MDR 4.3 50 10.2 70 9.6 80 8.1 95 7.8 100 6.7 100 5.3
MDR 7.3 50 9.2 65 8.4 80 7.4 95 7.0 100 6.0 100 4.8
MDR 10.9 50 8.7 65 7.9 80 6.9 90 6.4 100 5.7 100 4.5
MDR 14.5 50 8.2 65 7.4 80 6.5 90 6.0 100 5.4 100 4.3
HDR 24 50 6.7 65 6.1 75 5.1 90 4.9 95 4.3 100 3.5
HDR 43 50 5.3 65 4.7 75 4.0 85 3.8 95 3.4 100 2.7
N.Com 50 5.3 60 4.5 75 4.0 85 3.8 95 3.4 100 2.7
G.Com 50 4.7 60 4.1 75 3.6 85 3.4 90 2.9 100 2.4
O.P./Com 50 4.2 60 3.7 70 3.1 80 2.9 90 2.6 100 2.2
Limited I. 50 4.2 60 3.7 70 3.1 80 2.9 90 2.6 100 2.2
General I. 50 3.7 60 3.2 70 2.7 80 2.6 90 2.3 100 1.9
*See Table 3-1 for more detailed description
3-12
3. HYDRAULICS
A. Street -provide:
1) Depth of gutter flow calculation.
2) Inlet calculations.
3) Show gutter flow Q, inlet Q, and bypass Q on a plan of the street.
B. Storm Drain Pipes and Open Channels -provide:
1) Hydraulic loss calculations for: entrance, friction, junction, access
holes, bends, angles, reduction and enlargement.
2) Analyze existing conditions upstream and downstream from proposed
system, to be determined by the City Engineer on a case-by-case
basis.
3) Calculate critical depth and normal depth for open channel flow
conditions.
4) Design for non-silting velocity of 2 FPS in a two-year frequency storm
unless otherwise approved by the City Engineer.
5) All pipes and outlets shall show HGL, velocity and Q value(s) for
design storm.
6) Confluence angles shall be maintained between 45° and 90° from the
main upstream flow. Flows shall not oppose main line flows.
4. INLETS
A. Curb inlets at a sump condition should be designated for two CFS per lineal
foot of opening when headwater may rise to the top of curb.
B. Curb inlets on a continuous grade should be designed based on the
following equation:
Q = 0.7 L (a+ y)312
Where: y = depth of flow in approach gutter in feet
a = depth of depression of flow line at inlet in feet
L = length of clear opening in feet (maximum 30 feet)
Q = flow in CFS, use 100-year design storm minimum
C. Grated inlets should be avoided. When necessary, the design should be
based on the Bureau of Public Roads Nomographs (now known as the
Federal Highway Administration). All grated inlets shall be bicycle proof.
D. All catch basins shall have an access hole in the top unless access
through the grate section satisfactory to the City Engineer is provided.
Volume 1
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2/16/2016