HomeMy WebLinkAboutSDP 2021-0028; LEGOLAND PARKING STRUCTURE #2; DRAINAGE STUDY FOR LEGOLAND PARKING STRUCTURE #2; 2024-01-091
Drainage Study
for
LEGOLAND Parking Structure #2
SDP 2021-0028 / CDP 2021-0066
DWG No. 537-1A
Prepared for:
LEGOLAND California, LLC
1 Legoland Drive
Carlsbad, CA 92008
Prepared by:
Nasland Engineering
4740 Ruffner Street
San Diego, Ca. 92111
(858) 292-7770
NE Job No. 121-149.1
2
TABLE OF CONTENTS
1.0 PURPOSE OF STUDY........................................................................................................ 3
2.0 EXISTING CONDITIONS ……..…………………………..……………………………. 3
3.0 PROPOSED CONDITIONS …………..…………………………………………………. 4
4.0 HYDROMODIFICATION ……………………...………………..………………………. 4
5.0 METHODOLOGY ………………...……………………………………………………... 5
6.0 SUMMARY OF RESULTS ……………………...…………….………………………… 6
7.0 ANALYSIS ………………………………………..……………………………………… 8
8.0 CONCLUSION …..……………………………………………………………………...... 9
10
DECLARATION OF RESPONSIBLE CHARGE…………….………………………......
10
ATTACHMENTS
A. EXISTING AND PROPOSED HYDROLOGY MAPS
B. ONSITE HYDROLOGY CALCULATIONS
C.
D.
REFERENCE MAPS AND TABLES
HYDRAULIC ANALYSIS
3
1.0 PURPOSE OF THIS STUDY
The purpose of this hydrology study is to examine the existing hydrologic conditions and
the effects that the proposed parking structure will have on the existing drainage system.
The project is located within the guest parking lot just south of the existing employee
parking structure at the Legoland California Resort in the City of Carlsbad. The nearest
cross streets are Palomar Airport Road and The Crossings Drive. This study assesses the
hydrology associated with the immediate project area only.
CITY OF OCEANSIDE
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4
2.0 EXISTING CONDITION
The total existing watershed area is 2.5 acres which includes a small portion of the
existing employee parking lot areas to the north. Impervious surfaces within project
vicinity include an asphalt parking lot, asphalt street, concrete sidewalks, and concrete
curb and gutters. The existing impervious surface accommodate for 100% of the
watershed. The pervious surfaces surrounding the watershed include site landscaping
with mature trees and established shrubs surrounding the existing basin. There are no
undeveloped or open space areas within the project vicinity.
The existing topography slopes moderately south at approximately 5.5%. To
accommodate parking, the lot was graded in multiple terraces using steep landscape
planters to accommodate for the change in elevation. Each terrace is sloped between
2% and 3% and each planter has a slope of approximately 4 to 1. Two curb inlets are
located at each end of the south planter to collect surface runoff within the parking lot.
Approximately half of the site runoff is captured in a curb inlet and routed in a 30” RCP
to the west through the existing parking lot. The other half of the site runoff is captured
at the southeast curb inlet and routed in a 24” RCP toward The Crossings Drive. Both
storm drain systems are directed to a large existing bioretention facility located along
the frontage of Palomar Airport Road. The bioretention facility collects the excess
storm water generated from the entire parking lot, detains it and discharges it to Encinas
Creek on the south side of Palomar Airport Road.
3.0 PROPOSED CONDITIONS
The proposed project plans to construct a free standing parking structure with 4 levels of
parking. The parking structure will be cast in place concrete with smooth painted
surfaces. Site improvements include remedial grading to accommodate the parking
structure and site grading for surface driveway and walkways.
The proposed topography will mimic the existing sites hydrologic regime. Attenuation of
the storm water runoff will be achieved by routing proposed watershed to replaced curb
inlets at the existing southern curb location.
The total proposed watershed area is 2.56 acres comprising of a total of 4 drainage areas.
Drainage Areas 1.1, 1.2, 2.1, and 2.2 include drainage from the parking structure roof and
surrounding surface parking lot frontage which tie into the replaced curb inlets via
downspout piping and surface drainage to curb inlet opening. Drainage area 3 includes a
small section of area which will drain through a curb opening spillway and brow ditch
into the existing Biofiltration Basin. Drainage area 4 has been isolated from the project
watershed as well and drains away from the parking lot onto The Crossings Road. All
drainage areas still maintain its ultimate destination at the bioretention facility to the
South adjacent to Palomar Airport Road.
5
No water quality structural BMP have been proposed for this site area runoff due to
previously accounted for BMP sizing detailed in the Legoland Regional Biofiltration
Basin Storm Water Quality Management Plan (SDP 15-26 / CDP 15-50) prepared by
R.E.C. Consultants dated 6/30/18.
City of Carlsbad BMP Design Manual Chapter 4.4 requires trash capture devices for the
development of The LEGOLAND Parking Structure #2. This requirement will be met
and memorialized with installing ‘FlexStorm Connector Pipe Screen (CPS) trash capture
to the proposed A4 Cleanout downstream of DMA 2 (Total Area=7.22cfs tributary to the
to the CPS device) at POC 2. The standard 3L18H-Bypass-Shape CPS has been selected
to screen over the existing 24” RCP outlet. See Appendix D for Trash Screen Hydraulic
calculations.
4.0 HYDROMODIFICATION
The site includes a total project limit of disturbance area of 3.012 acres. Within the site
project disturbance limits there is an existing 109,827 sf impervious area and proposed
121,081 sf proposed impervious area which results in a total site increase of 10.2%.
Hydromodification sizing for the increase of impervious area on this site has been
accounted for by the Legoland Regional Water Quality and Hydromodification BMP
report (SDP 15-26 / CDP 15-50) prepared by R.E.C. dated 6/30/2018 and latest
Amendment dated 2/21/19. See proposed Amendment to Legoland Regional Biofiltration
Basin Storm Water Quality Management Plan (SDP 15-26 / CDP 15-50) for equivalent
area calculations prepared by Nasland Engineering on October 26, 2023 for more
information.
5.0 METHODOLOGY
Surface data and runoff equations were acquired from the County of San Diego
Hydrology Manual dated June 2003 and the County of San Diego Hydraulic Design
Manual dated September 2014. All maps and tables utilized from these Manuals are
located in the maps and tables attachment at the end of this report.
• The runoff coefficient C is determined using table 3-1 on page 65 of the
County of San Diego Hydrology Design Manual or by using the following
equation:
C=0.9 x (% Impervious) + Cp x (1 - %impervious)
Where: Cp = the pervious coefficient value for undisturbed natural
terrain for type D soil (Cp=0.35)
• The time of concentration for sheet flow conditions is determined using the
chart and equation from the Figure 3-3 “Urban Area Overland Time of Flow
Nomographs”.
6
• The time of concentration for channelized flow conditions utilized Manning’s
equation or Figure 3-7
• Manning Roughness Coefficients were determined using table 1-104-14A.
• The intensity (I) is calculated as a function of time of concentration and can be
determined by using the Intensity Duration Design Chart (Figure 3-1) or from
the equation; I = 7.44 P6 D-0.645
Where: P6 = 6-Hour Precipitation Depth (inch)
D = time of concentration (minutes)
• The runoff discharge (Q) is calculated using the Rational Method.
Q=CIA
Q = Storm Specific Runoff discharge (cfs)
C = runoff coefficient
I = Storm Specific Rainfall intensity (in/hr)
A = Watershed area (acres)
HYDRAULIC DESIGN CRITERIA
Drainage improvements for Legoland Parking Structure must collect, convey, detain, and
treat all onsite excess storm water. The hydraulic analysis of onsite drainage features is
modeled after the County of San Diego Hydraulic Design Manual. See Appendix D for
inlet capacity and proposed storm drain pipe capacity calculations.
Curb Inlet Design Capacity
Inlet capacity is the rate of storm water the curb inlet can capture. All inlets are located in
a sump condition and must fully intercept the peak discharge from the 100-year design
event.
The inlet capacity for the Type B curb inlets were analyzed under both weir and orifice
conditions. The inlet capacity governed by the weir and orifice condition is calculated
as:
𝑄=𝐶𝑤𝐿𝑤𝑑3/2 For Curb Inlets (Weir Condition)
Where:
Q= inlet capacity governed by weir flow (cfs)
Cw= Weir Coefficient (Cw = 3.00)
Pe= Effective Perimeter for sides accepting flow (ft)
LW= Effective Weir Length (Curb Opening) (ft)
d = depth of flow at the grate (ft)
𝑄=𝐶𝑛ℎ𝐿(2𝑔𝑑)1/2 For Curb Inlets (Orifice Flow Condition)
Where:
Q = inlet capacity governed by orifice flow (cfs)
L = Curb Opening Length
7
Co = Orifice Coefficient (CO = 0.67)
g = gravitational acceleration (32.17 ft/s2)
Ae = Effective Area (ft2)
d = depth of flow at the grate (ft)
h = Curb Opening Height
Storm Drain Pipes
Underground storm drain pipes are designed to have a capacity to convey the 100-year
design storm. Analysis of the flow conditions for the storm drain assumes a uniform
flow condition. This assumption allows the use of the Manning Equation:
𝑄=1.49
𝑛𝐴𝑄2/3𝑄1/2
Where
Q = discharge (cfs)
n = Manning Coefficient
A = Flow Area (ft2)
R = Hydraulic Radius (ft)
S = Swale slope (ft/ft)
Storm Drain Pipes
Trash capture standard CPS model number has been selected based on screen length,
height, bypass height, and screen shape.
Orifice bypass calculation has been used to determine the maximum screen flow and
bypass through the 3L18H-Bypass-Shape.
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8
6.0 SUMMARY OF RESULTS
This summary shows the results for the existing and proposed onsite hydrology. The
onsite hydrology results show the existing runoff rates and the proposed unmitigated
hydrologic conditions for a 6-hour 100 year design storm. For hydrologic calculations
and the equations utilized in the study, see Attachment B: Onsite Hydrology
Calculations located in the back of this report.
Rainfall Precipitation Depths
85th
Percentile
Event
10 Year
Event
100 Year
Event
P6 = - 1.8 2.5
P24 = 0.58 3.0 4.25
P6/P24 = - 60% 59%
Adjusted P6 = 0.58 1.8 2.5
Note:
• A minimum time of concentration of 5 minutes was utilized.
• The project assumes hydrologic type D soil.
9
100 Year Design Storm
Existing:
Proposed (Unmitigated):
Q100 Pre vs. Post Conditions:
EX. DMA C Value Tc (mins)
Intensity
(I, in/hr)
Area
(acres)
Runoff
(Q, cfs)
100 Year
E1.0 0.90 5.00 6.59 1.27 7.51 POC 1
E2.0 0.90 5.00 6.59 1.25 7.41 POC 2
EX. SUMMARY
DRAINAGE
AREA C Value Tc (mins)
Intensity
(I, in/hr)
Area
(acres)
Runoff
(Q, cfs)
100 Year
1.1 0.90 5.00 6.59 1.14 6.75
1.2 0.85 5.00 6.59 0.09 0.50
7.25
2.1 0.90 5.00 6.59 1.11 6.58
2.2 0.85 5.00 6.59 0.15 0.84
7.42
3 0.66 5.00 6.59 0.06 0.26
4 0.90 5.00 6.59 0.05 0.30
TOTAL POC 1
TOTAL POC 2
Summary
POC
EXISTING
Q100 (CFS)
PROPOSED
Q100 (CFS)
DELTA
Q100
(CFS)
1 7.51 7.25 -0.26
2 7.41 7.42 0.01
Summary
10
7.0 ANALYSIS
The runoff rates in this study have been calculated in order to compare the pre site
condition runoff to the post site condition runoff. It has been observed that the total
watershed runoff has been accounted for at each point of connection.
After slight adjustments to the various proposed drainage areas, it has been confirmed
that the total proposed development will reduce the overall peak runoff rate entering each
catch basin POC. The total decrease in peak runoff is 0.25 CFS drainage to POC 1 and
calculated equivalent CFS to POC 2. A curb inlet is proposed at the new low point along
the southern curb to collect the drive aisle runoff from DMA 1.2 and convey the parking
structure roof downspout runoff entering POC 1 sized at the same drainage capacity. A
replaced curb inlet is proposed to collect drive aisle runoff from DMA 2.2 and convey
DMA 2.1 into POC 2 discharge. See Appendix D for catch basin hydraulic sizing.
Each of these POCs are piped and routed to the existing bioretention basin adjacent to
Palomar Airport Road. This existing basin is sized to detain the 100 year storm prior to
releasing excess storm water to Encinas Creek on the south side of Palomar Airport
Road.
Trash Capture CPS pipe screen protection device has a total Q screen flow rate of 8.72
cfs and a 12” bypass freeboard of 13.19 CFS. The A4 cleanout has a depth of 7.2 feet
which allows for the required bypass to convey the peak flow of 7.20 CFS coming from
combined DMA 2.1 and 2.2. See appendix D for CPS sizing calculations.
11
8.0 CONCLUSION
This study has discussed the existing and proposed conditions associated with the
construction of a new parking structure within Legoland Parking Structure #2. Based on
the calculations presented in this study, the proposed development will not pose any
hydrologic or hydraulic conditions of concern when released to the existing public storm
drain system. The proposed conditions will maintain the runoff entering the replaced
curb inlet structures at POC 1 and POC 2. This project will maintain and slightly reduce
the rate at which storm water will discharge from the site, therefore will not pose any
impacts to the existing system.
Although the overall proposed site results in a 1.0% increase of impervious area, this site
will not require treatment area as the BMP sizing has been accounted for in the Legoland
Regional Biofiltration Basin Storm Water Quality Management Plan (SDP 15-26 / CDP
15-50) prepared by R.E.C. Consultants dated 6/30/18. The increase in impervious area
will be memorialized and deducted from the BMP area surplus a new amendment to the
Legoland Regional Biofiltration Basin SWQMP.
The proposed offsite redirection of flows will not pose concern to existing storm drain
systems. ‘DMA 3’ flows to the existing biofiltration basin constructed for the parking
structure north of the site. The existing biofiltration basin has been sized including
‘DMA 3’ within ‘DMA 1’ from SWQMP No. 16-25, Storm Water Quality Management
Plan for Legoland Parking Structure, SDP96-14(I), prepared 8/8/2016. Since we are
decreasing the amount of impervious area within ‘DMA 3’ by 500sf; no alternations to
the existing biofiltration basin are required. ‘DMA 4’ encompasses a de-minimis area
which is redirected from the proposed parking structure frontage and onto The Crossings
Drive. This existing area ultimately drains to the same storm drain network as it will in
the proposed conditions, therefore will not create a hydraulic or water quality impact to
the existing storm drain network on The Crossings Drive.
12
9.0 DECLARATION OF RESPONSIBLE CHARGE
I hereby declare that I am the engineer of work for this project, that I have exercised
responsible charge over the design of the project as defined in section 6703 of the
Business and Professions Code, and that the design is consistent with the current
standards.
I understand that the check of the project drawings and specifications by the City of
Carlsbad is confined to a review only and does not relieve me, as Engineer of Work, of
my responsibilities for project design.
James J linn Date
R.C.E. 84231
Exp. 9-30-2025
1/09/24
ATTACHMENT A: EXISTING AND PROPOSED SITE
HYDROLOGY MAPS
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Civil Engineering T (858) 292-7770
Nasland Surveying 4740 Ruffner Street 0
Land Planning San Diego, CA 92111
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LEGEND
PROPOSED IMPROVEMENTS
LANDSCAPE
BASIN PERIMETER
STORM DRAIN
FLOW LINE
SITE DATA
TOTAL DRAINAGE AREA:
LOGIC SOIL GROUP:
EXHIBIT
------------SD---
.<=·<=·<=·<=.
2.52 ACRES
D
DEPTH TO GROUNDWATER: GREATER THAN 20'
EX.SUMMARY
Intensity Area Runoff
EX. OMA C Value Tc (mins) (I, in/hr) (acres) (Q, cfs)
10 Year
E1.0 0.90 5.00 4.74 1.27 5.40 POC 1
E2.0 0.90 5.00 4.74 1.25 5.34 POC2
100 Year
E1.0 0.90 5.00 6.59 1.27 7.51 POC 1
E2.0 0.90 5.00 6.59 1.25 7.41 POC2
EXISTING HYDROLOGY
OMA EXHIBIT
CITY OF CARLSBAD
ENGINEERING DEPARTMENT
50 100
PROJECT NO.
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Nasland Civil Engineering
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T (858) 292-7770
4740 Ruffner Street
San Diego, CA 92111
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0 50
LEGEND
PROPOSED IMPROVEMENTS
LANDSCAPE
IMPERVIOUS SURFACE
BASIN PERIMETER
STORM DRAIN
FLOW LINE
SITE DATA
TOTAL WATERSHED AREA:
LOGIC SOIL GROUP:
DEPTH TO GROUNDWATER:
EXHIBIT
--------SD---
. <=·<=·<=·<=·<=·<=.
2.56 ACRES
D
GREATER
THAN 20'
Summarv
DRAINAGE Intensity Area Runoff
AREA C Value Tc (mins) (I, in/hr) (acres) (Q, cfs)
100 Year
1.1 0.90 5.00 6.59 1.14 6.75
1.2 0.85 5.00 6.59 0.09 0.50
TOTAL POC 1 7.25
2.1 0.90 5.00 6.59 1. 11 6.58
2.2 0.85 5.00 6.59 0.15 0.84
TOTAL POC 2 7.42
3 0.66 5.00 6.59 0.06 0.26
4 0.90 5.00 6.59 0.05 0.30
PROPOSED HYDROLOGY
100 DMA EXHIBIT
CITY OF CARLSBAD
ENGINEERING DEPARTMENT
SCALE 1 "=50'
I 11
PROJECT NO.
I
ATTACHMENT B: CALCULATIONS
EXISTING CONDITIONS
Runoff Coefficient
EX. DMA
Area
(acres)% Impervious % Pervious Description
Subbasin
C Value
E1.0 1.27 99.5% 0.5% Parking Lot 0.90
E2.0 1.25 100.0% 0.0% Parking Lot 0.90
2.52
Note: The site consists of hydrologic soil class D
The Cp value for Hydrologic soil class D is Cp=0.35
Time of concentration
Sheet Flow
EX. DMA C Value L (ft) Delta (ft) Slope (%) Ti (min)
E1.0 0.90 100.00 2.90 2.90 2.56
E2.0 0.90 100.00 2.90 2.90 2.52
Note: Minimum time of concentration (Tc) for all basins is 5 minutes
Concentrated Flow
EX. DMA Description L (ft) Delta (ft) Slope (%) Tt (min)
E1.0 kirpach 226 6.60 3.00 1.98
E2.0 kirpach 228 6.70 2.90 1.99
Total Time of Concentration
EX. DMA Ti (min)Tt (min) Tc (min)
E1.0 2.56 1.98 5.00
E2.0 2.52 1.99 5.00
Note: Minimum time of concentration (Tc) for all basins is 5 minutes
10 YEAR - 6 HOUR Storm P6 = 1.8 in
EX. DMA C Value Tc (mins)
Intensity
(in/hr)Area (acres)
Runoff
(Q, cfs)
E1.0 0.90 5.00 4.74 1.27 5.40
E2.0 0.90 5.00 4.74 1.25 5.34
Note:See the charts and graphs used for the hydrologic calculations at the end of this study.
100 YEAR - 6 HOUR Storm P6 = 2.5 in
EX. DMA C Value Tc (mins)
Intensity
(in/hr)Area (acres)
Runoff
(Q, cfs)
E1.0 0.90 5.00 6.59 1.27 7.51
E2.0 0.90 5.00 6.59 1.25 7.41
Note:See the charts and graphs used for the hydrologic calculations at the end of this study.
T, = 1.8(1.1 -C},/I
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D
PROPOSED CONDITIONS
Runoff Coefficient
DMA Area (acres)% Impervious % Pervious Description C Value
1.1 1.14 100.0%0.0%Parking Lot 0.90
1.2 0.09 90.0%10.0%Parking Lot 0.85
2.1 1.11 100.0%0.0%Parking Lot 0.90
2.2 0.11 91.0%9.0%Parking Lot 0.85
3 0.06 56.0%44.0%Parking Lot 0.66
4 0.05 100.0%0.0%Parking Lot 0.90
Note: The site consists of hydrologic soil class D 0.84
The Cp value for Hydrologic soil class D is Cp=0.35
2.56
Time of concentration
Sheet Flow
DMA Node C Value L (ft)Delta (ft)Slope (%)Tc (min)
1.1 0.90 100.00 3.00 1.50 3.14
1.2 0.85 133.00 3.00 1.50 4.62
2.1 0.90 100.00 3.00 1.50 3.14
2.2 0.85 77.00 3.00 1.50 3.44
3 0.66 63.00 6.00 10.00 2.93
4 0.90 100.00 6.00 7.00 1.88
Total Time of Concentration Tc = Ti + Tt
DMA Ti (min)Tc (min)
1.1 3.14 5.00
1.2 4.62 5.00
2.1 3.14 5.00
2.2 3.44 5.00
3 2.93 5.00
4 1.88 5.00
Note: Minimum of 5 minute Time of Concentration was utilized
10 YEAR - 6 HOUR Storm P6 =1.8 in
DMA C Value Tc (mins)
Intensity
(I, in/hr) Area (acres)
Runoff
(Q, cfs)
1.1 0.90 5.00 4.74 1.14 4.87
1.2 0.85 5.00 4.74 0.09 0.36
BASIN 1
TOTAL 5.23
2.1 0.90 5.00 4.74 1.11 4.74
2.2 0.85 5.00 4.74 0.11 0.44
BASIN 2
TOTAL 5.18
3 0.66 5.00 4.74 0.06 0.19
4 0.90 5.00 4.74 0.05 0.21
Note:See the charts and graphs used for the hydrologic calculations at the end of this study.
100 YEAR - 6 HOUR Storm P6 =2.5 in
DMA C Value Tc (mins)
Intensity
(I, in/hr) Area (acres)
Runoff
(Q, cfs)
1.1 0.90 5.00 6.59 1.14 6.76
1.2 0.85 5.00 6.59 0.09 0.50
POC 1
TOTAL 7.26
2.1 0.90 5.00 6.59 1.11 6.58
2.2 0.85 5.00 6.59 0.11 0.62
BASIN 2
TOTAL 7.20
3 0.66 5.00 6.59 0.06 0.26
4 0.90 5.00 6.59 0.05 0.30
Note:See the charts and graphs used for the hydrologic calculations at the end of this study.
*DMA 3 DRAINS TO EXISTING BMP
*DMA 4 DRAINS OFFSITE
3/2/2023 JOB NO. 107-217.1
r: = Ul{1.1 -C}.fi.
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ATTACHMENT C: REFERENCE MAPS AND TABLES
San Diego County Hydrology Manual Section: 3 Date: June 2003 Page: 6 of 26
Table 3-1 RUNOFF COEFFICIENTS FOR URBAN AREAS
Land Use Runoff Coefficient “C”
Soil Type
NRCS Elements County Elements % IMPER. A B C D
Undisturbed Natural Terrain (Natural) Permanent Open Space 0* 0.20 0.25 0.30 0.35
Low Density Residential (LDR) Residential, 1.0 DU/A or less 10 0.27 0.32 0.36 0.41
Low Density Residential (LDR) Residential, 2.0 DU/A or less 20 0.34 0.38 0.42 0.46
Low Density Residential (LDR) Residential, 2.9 DU/A or less 25 0.38 0.41 0.45 0.49
Medium Density Residential (MDR) Residential, 4.3 DU/A or less 30 0.41 0.45 0.48 0.52
Medium Density Residential (MDR) Residential, 7.3 DU/A or less 40 0.48 0.51 0.54 0.57
Medium Density Residential (MDR) Residential, 10.9 DU/A or less 45 0.52 0.54 0.57 0.60
Medium Density Residential (MDR) Residential, 14.5 DU/A or less 50 0.55 0.58 0.60 0.63
High Density Residential (HDR) Residential, 24.0 DU/A or less 65 0.66 0.67 0.69 0.71
High Density Residential (HDR) Residential, 43.0 DU/A or less 80 0.76 0.77 0.78 0.79
Commercial/Industrial (N. Com) Neighborhood Commercial 80 0.76 0.77 0.78 0.79
Commercial/Industrial (G. Com) General Commercial 85 0.80 0.80 0.81 0.82
Commercial/Industrial (O.P. Com) Office Professional/Commercial 90 0.83 0.84 0.84 0.85
Commercial/Industrial (Limited I.) Limited Industrial 90 0.83 0.84 0.84 0.85
Commercial/Industrial (General I.) General Industrial 95 0.87 0.87 0.87 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
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Hydrology Manual
Rainfall Isopluvials
10 Year Rainfall Event • 6 Hours
lsopluvial (inches)
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Hydrology Manual
Rainfall Isopluvials
10 Year Rainfall Event-24 Hours
I so pluvial (inches)
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County of San Diego
Hydrology Manual
100 Year Rainfall Event-6 Hours
I so pluvial (inches)
DPW
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TMIS 1,1,'P IS PR0\110£() v,m-,ollT W#J:$.ANTV cs ANY KINI>, Eln-lER £XPRESS
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County of San Diego
Hydrology Manual
Rainfall Isopluvials
100 Year Rainfall Event• 24 Hours
0
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s:tGIS
We H:1,•c San Diego Owcrc<l!
THIS UAP IS PRO\i1DED wm-tOUT WAASW,ITY OF ,WV KIND. EITHER EXPRESS
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6 7 8 ·9 10 15 20 30 40 50 2 3 4 5 6 Minutes Hours
Duration
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 100 yr maps induded
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
applicaple 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) P5 = in. P24 = ----2. = 0;o<2l --' --'P24 --
(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 1.5 2 2.5 3 3.5-4 4.5 5 5.5 6
Duration I I I -I -·1 I I I • I ' I
5 2.63 3.95 5.27 6.59 7.90 9.22 110.54 11.86 13.17 14.49 15.81
7 TI2"°3-:1s-4.24 5.30 ·6.36 7.42 : 8.48 9.54 10.60°11.66°12.72
10 1.68 • 2.5:3° 3.37 . 4.21 5.05 • 5.90 1 6.74 7.58 8.42 • 9.27 • 10.11
ts (30 "f!fs 2.59:i:2T 3.ss·4_54 s.19 s .84-6.49 . 'i.Th 1.1a
20 1.08 1.62 2.15 1 2,_69 ~_3.23. 3.77 .,._ 4.31 4.85-5.39--5.~j : ~.46
25 0.93 1.40 1.87 2.33 2.80 3.27 3,73 4.20 4.67 5.13 5.60
30 0.83 1.24 1.615 2.07 . 2.49 2.90: 3..32 3.73 4.15 ' 4.56 4.98
40 0.69 ·1.03 1.38 1.72 °2.07°2.41. 2.76 . 3.10 3.45 . 3.79 4.13
SO 0.60 0.90~1.19 1,49 1.79 2.09 : 2.39 '2.69 . 2.98 ' 3.28 3.58
so p.53 ).ao:1.00: 1.:i3~1 sguis: 2.12 2:ag 2.ss ;2 .92 3.18
90 0.41 0.61 0.82 1.02 1.23 1.431 1.63 1.84 2.04 2.25 2.45 -r20 0 ~34 ·o_s,-0.68 • o:as-1.02 1.191 1.36 • 1.53 -1.10 • 1.a7' 2:04
15Q ~29 ~0.4(0.59 ° 0.73~0.88. 1.03; 1.18 1.32 . 1.47 ~ 1.62 1.76
180 0.26 . 0.39, 0.52_ 0.65_ 0.78 _0.9\ 1.04 . 1.18 _ 1.31 1.44 .. 1.57
240 0.22 0.33 0.43 0.54 0.65 0.76 0.87 0.98 1.08 1.19 1.30 ~ 0.10 0.28 o.aa • o.47 -o-:-56 • 6.66 • 0.15 o.ss o.94 • 1.63-1.13
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F I G U R E ~
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EXAMPLE:
Given: Watercourse Distance (D} = 70 Feet
Slope (s) =1.3%
Runoff Coefficient (C) = 0 .41
Overland Flow Time (T) = 9.5 Minutes
T= 1.8 (1.1-C) D
3\fs
SOURCE: Airport Drainage, Federal Aviation Administration, 1965
Rational Formula -Overland Time of Flow Nomograph
(/}
UJ I-
=> z
20 ~ z
w ~ I-
~ 0 ...J u.
Cl 10 z <(
...J a:: UJ > 0
FIGURE
3.3
EQUATION: V = 1.49 R213 s112
n
(J) I
0 .E
Q)
0..
Q)
~
C
0.3
0.2
0.15
0.10
0.09
0.08
0.07
0.06
0.05
0.04
0.03
0.02
0.01
0.009
0.008 u W 0.007 :::J a.. ::, g 0.006 ~
CJ) . 0.005 O
>-0.004 c-,<:l1/ I ~ C'i-.;;.r
~
0.002
0.001
0.0009
0.0008
0.0007
0.0006
0.0005
0.0004
0.0003
E
0.2
0.3
0.4
0.5
4
5
6
7
8
9
10
20
SOURCE: USDOT, FHWA, HDS-3 (1961)
GENERAL SOLUTION
Manning's Equation Nomograph
r o
r o
30
20
2
1.0
0.9
0.8
0.7
0.6
0.5
C
c Q) ·u
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0.02
0.03
0.04
0.05
0.06
0.07
0.08
0.09
0.10
0.2
0.3
0.4
FIGURE
~
ATTACHMENT D: HYDRAULIC ANALYSIS
CURB INLET HYDAULIC ANALYSIS
Page A-4 San Diego County Hydraulic Design Manual
September 2014
Table A-2 Average Manning Roughness Coefficients for Closed Conduits3
Reinforced Concrete Pipe (RCP) ............................................................................................. 0.013
Corrugated Metal Pipe and Pipe Arch
2-3/8 x 1/2 inch Corrugations
Unlined ......................................................................................................................... 0.024
Half Lined
Full Flow ................................................................................................................ 0.018
d/D>=0.60 ............................................................................................................. 0.016
d/D<0.60 ................................................................................................................ 0.013
Fully Lined ................................................................................................................... 0.013
3 x 1 inch Corrugations ...................................................................................................... 0.027
6 x 2 inch Corrugations ...................................................................................................... 0.032
Spiral Rib Pipe ................................................................................................................... 0.013
Helically Wound Pipe
18-inch ......................................................................................................................... 0.015
24-inch ......................................................................................................................... 0.017
30-inch ......................................................................................................................... 0.019
36-inch ......................................................................................................................... 0.021
42-inch ......................................................................................................................... 0.022
48-inch ......................................................................................................................... 0.023
Plastic Pipe (HPDE and PVC)
Smooth ............................................................................................................................... 0.013
Corrugated ......................................................................................................................... 0.024
Vitrified Clay Pipe ..................................................................................................................... 0.014
Cast-Iron Pipe (Uncoated) ........................................................................................................ 0.013
Steel Pipe ................................................................................................................................. 0.011
Brick .......................................................................................................................................... 0.017
Cast-In-Place Concrete Pipe
Rough Wood Forms ........................................................................................................... 0.017
Smooth Wood or Steel Forms ............................................................................................ 0.014
3 Based on materials and workmanship required by standard specifications.
Table A-2
Weir Coefficient:3.00
Orifice Coefficient 0.67
Curb Inlet Opening Height: 0.50 ft
Gutter Depression Depth, a: 0.33 ft
Curb Inlets
Depth of
Flow
(ft) Qapproach
(cfs)
Curb Inlet
Opening
(ft)
Effective
Curb Inlet
Opening,
Lw (ft)
effective
Depth
do (ft)
Inlet
Capacity
(Weir
Flow)
(cfs)
Inlet
Capacity
(Orifice
Flow)
Inlet
Capacity
(cfs)
Percent
Intercept
ed
100-YR
0.50 0.7 4.00 4.00 0.24 4.2 5.3 4.24 100%
0.50 0.6 4.00 4.00 0.24 4.2 5.3 4.24 100%
Assumption
* Curb inlet and grate capacity is analyzed under both weir and orifice conditions.
The capacity of the inlet is the smaller of the orifice or the weir condition.
* Curb Inlets and Grates are considered in sump condition with the inlet apron if
1) the inlet capacity is greater than the approaching excess storm water; and
2) The flow is fully contained within the swale.
* The adjusted inlet capacity is the capacity of the grate with pooling behind the 4" weir.
The pooling depth is taken as 3" (0.25') so that 1" of freeboard is provided behind the weir.
The inlet capacity will be taken as the maximum of the Pooling Capacity or the flow capacity,
as long as the flow capacity satisfies the sump conditions assumed above. All other flow will be bypassed.
Curb Inlet Analysis
TYPE B CURB INLET PARAMETERS:
Type B Curb Inlet (POC 2)
Approach Flow Inlet Geometry Inlet Capacity
Description
Type B Curb Inlet (POC 1)
I I
I I
STORM DRAIN PIPE ANALYSIS
Channel Report
Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc.Tuesday, Oct 24 2023
POC 1 - 18 IN
Circular
Diameter (ft)= 1.50
Invert Elev (ft) = 113.41
Slope (%)= 1.00
N-Value = 0.013
Calculations
Compute by:Known Q
Known Q (cfs) = 6.76
Highlighted
Depth (ft)= 0.88
Q (cfs)= 6.760
Area (sqft)= 1.08
Velocity (ft/s)= 6.24
Wetted Perim (ft) = 2.62
Crit Depth, Yc (ft) = 1.01
Top Width (ft)= 1.48
EGL (ft)= 1.49
0 1 2 3
Elev (ft)Section
112.50
113.00
113.50
114.00
114.50
115.00
Reach (ft)
-_.,,-------' ~ " -~
( -\
V ' --
-
-
)
7
/ -/ ----
Channel Report
Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc.Tuesday, Oct 24 2023
POC 1 - EX 30 IN
Circular
Diameter (ft)= 2.50
Invert Elev (ft) = 113.41
Slope (%)= 1.00
N-Value = 0.013
Calculations
Compute by:Known Q
Known Q (cfs) = 7.26
Highlighted
Depth (ft)= 0.72
Q (cfs)= 7.260
Area (sqft)= 1.18
Velocity (ft/s)= 6.18
Wetted Perim (ft) = 2.84
Crit Depth, Yc (ft) = 0.90
Top Width (ft)= 2.27
EGL (ft)= 1.31
0 1 2 3 4
Elev (ft)Section
112.50
113.00
113.50
114.00
114.50
115.00
115.50
116.00
Reach (ft)
~ ---------~ ~ -/--' / -~ T --\ , _, -
- -
-J -,_
,-, ,_ V
~ -I
~ / -
'-/ '--_/ -........... ------
Channel Report
Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc.Tuesday, Oct 24 2023
POC 2 - 18 IN
Circular
Diameter (ft)= 1.50
Invert Elev (ft) = 112.10
Slope (%)= 1.00
N-Value = 0.013
Calculations
Compute by:Known Q
Known Q (cfs) = 7.20
Highlighted
Depth (ft)= 0.91
Q (cfs)= 7.200
Area (sqft)= 1.13
Velocity (ft/s)= 6.39
Wetted Perim (ft) = 2.68
Crit Depth, Yc (ft) = 1.04
Top Width (ft)= 1.46
EGL (ft)= 1.55
0 1 2 3
Elev (ft)Section
111.50
112.00
112.50
113.00
113.50
114.00
Reach (ft)
--~ ---------~
-/ -L
7 v -'\ --
\ )
\. /
' /
' / --~
--
Channel Report
Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc.Tuesday, Oct 24 2023
POC 2 - EX 24 IN
Circular
Diameter (ft)= 2.00
Invert Elev (ft) = 111.80
Slope (%)= 24.00
N-Value = 0.013
Calculations
Compute by:Known Q
Known Q (cfs) = 7.20
Highlighted
Depth (ft)= 0.35
Q (cfs)= 7.200
Area (sqft)= 0.37
Velocity (ft/s)= 19.39
Wetted Perim (ft) = 1.73
Crit Depth, Yc (ft) = 0.95
Top Width (ft)= 1.52
EGL (ft)= 6.20
0 1 2 3 4
Elev (ft)Depth (ft)Section
111.00 -0.80
111.50 -0.30
112.00 0.20
112.50 0.70
113.00 1.20
113.50 1.70
114.00 2.20
Reach (ft)
--------.....
/ ..........
"" -/ ~ -,
7 .,
l J
~ -'Olli; 7 !--, --= ~-/-
-~ ~ -
ADS FLEXSTORM CPS U EXT
TRASH SCREEN HYDRAULIC ANALYSIS
Page | 13
APPENDIX A. Design Criteria and Sample Calculations
CPS FLOW CALCULATIONS
STANDARD LENGTHS. VARIABLE BYPASS HEIGHTS
ADS CPS units are !itandardized with a pre-set Length of
s.creen [L). The heigJlt of the bypass is the variable used to
confirm th at the tota I 0.vpo,• for the CPS with lid design
exceeds the Max Q,0 for a certain CB width. The sizing table
below shows th e resultant Or"I?'" for the various B (bypa.ss
heights).
Defini:ning the Orifice bypass equation tor CPS with deflector lids
°-t,ypass = CbypassAbypass ✓ 2g H
~ •• = .6 (coelificient)
g= 3 2.2 ftls'
~ =L tfu:,(1EJ-.•,f>ChlbotJaahdJ.hll
~ = depth of water to centroid of bypass CPS U
SIZING TABLE MINIMUM BYPASS RATINGS for lid desi ns with 6" Freeboard
CPS Flow Rates by Model B(bypass
height)= 4"
B (bypass ll [bypass B(bypass B (bypass
height)= 6" height) =8" height)= 10" height) = 12"
Model Screen Screen A,.,-.,,0 et 0.,,.,0 Flow lt.,pm Q4 H., Length Height D~!'.!1 11~) Rate (ds) (ft) Q6 H, QS Hs QlO H10 Q12
3L18H-B ass-Sha e 3 18 1.80 8.72 3.00 3.93 8 5.52 7 6.81 6 7.77 5 13.19
4l18H-Bypass-Shape 4 18 2..45 11.84
SL18H-Bypass-Shape 5 18 3.09 14.96
Determine CPS model number based on screen length and height
-bypass height-and s.creen shape_ For example Model 3U8H-8-U
is 3' wide x 18" tall, has 8" bypass height, and is "U" shaped.
Cu!itom lengths and heights are available for any catch basin.
Example Seleotion and Calculation:
4.00 5.24 8 7.35 7 9.08
5.00 6.55 8 9.19 7 11.35
&yp.i~!. r.'tirn,;::-. in 81.-ck ;;;Je for 3.5' Vb MinimWT:'I C;tc 8.i:!:in De,p
&yp.r.~!. r;;;tir;!. in Re .ire r~• Vb Minimum Catch B.tl"11 ~pths-
6 10.36 5 17.58
6 12.95 5 2.1.98
Assume we have a 7' wide catch basin with a depth Vb of 3.5' and 18" connector pipe. The Ma:x Q,is 1.2 CFS and the Ma:x Q10 is 5.3 CFS per the hydrology
!itudy table to the right. Select th e appropriate s.creen to pass the 1 year flow then determine the minimum bypass height required to pass the 10 year
flow. The 3L18H-6B s.creen (highlighted tn green) passes 8.52 CFS far e:xceeding the 1.2 CFS requirement. According to the sizing table that unit will bypass
5..5-2 CFS with a 6" bypass heigllt based on the OrifiGe Flow bypass equation which is greater than the required 5.3 CFS maximum lOyrflow seen by the 7'
wide catch basin. The bypass is calculated as follows:
Q"IP',. = ~,,.A,,~, \fiiH
~ = .6 (orifice coefficiem)
g= 32.2 ft/s2
A,,.,,,.,. = L [1e"-""'°''"""'IX h •>w='-"<;ht] = (3 X 6/12) = 1.5 ft2
H = depth of water to centroid of bypass (maintaining 6" freeboard)
We need to check Clearance and determine the H
Clearance = Vdepth-Hscreen-Hbypass-rnrb height (mu!it always be > 4")
Clearance = 42"-18"-6"-8"=10'"
H = H bypass/2 + Cleara nee -6" freeboa rd (sized conservatively)
H = 6/2 + 10 -6 = T' or .583 ft
Finally, O.Y?"' = ~po,,A'Y?"' ,fijiii a_,= ,6 X 1.5 v'2 X 32, 2 X. 583 = 5.52.cfS
f:qr,Bl.oo
H,,
10
10
10
Ca·tch B,11sin R:,11tine~ far~ y!!.u
,11nd ten y9r rain ~enls 11:S
determlMd by LA County
h dra ~tu:dJB
CII widd, M,xO,m Ma°-1,1
() (ml tct.)
l-5 u 0.6
5.3 1.2
10 7-5 1.7
1• 10 2.2
21 ll.9 ].1
ZS 17.3 3.S
Page | 14
Appendix B. Specification and Design Drawings
ADS FLEXSTORM: CONNECTOR PIPE SCREEN (CPS)
PROTECTIVE BYPASS UD
CPS L 14 GA 5 MM PERFORATED
STAINLESS STEEL 50% OPEN AREA
SIZING TABLE
CPS Flow Rates by Model
M odel Screen Screen ~c:rtien {Net O screen Flow
Length Height open ;,re;,) Rate (cfs)
3Ll8H-Bypass-Shape 3 18 1.80 8 .72
4Ll8H-Bypass-Shape 4 18 2.45 11.84
SL18H-Bypass-Shape 5 18 3.09 14.96
lt,ypass
(ft)
3.00
4 .00
5.00
CPS U
12 GA U-CHANNEL
STIFFENER (Typ.)
3/8" WEDGE
ANCHOR BOLTS
SLOTTED HOLES FOR
SLOPED CATCH BASIN FLOORS
CPS U-EXT
MINIMUM BYPASS RATINGS for lid designs with 6" Freeboard
B (bypass B (bypass B (bypass B (bypass B (bypass
hei ht =4" hei ht = 6" hei ht = 8" hei ht = 10" hei ht = 12"
Q4 H• Q6 H6 Q8 Ha QlO H10 Q12 H12
3.93 8 5.52 7 6.81 6 7 .77 5 13.19 10
5.24 8 7.35 7 9.08 6 10.36 5 17.58 10
6.55 8 9 .19 7 11.35 6 12.95 5 21.98 10
Determine CPS model number based on screen length and height -bypass height -and screen shape. For example
Model 3L18H-8-U is 3' wide x 18" tall, has 8" bypass height, and is "U" shaped. Custom lengths and heights are available
for an catch basin.
14GA5MM
PERFORATED
SCREEN50%
OPEN ---------------------7 N
3" (TYP)
3 .. BASE SUPPORT
BRACKET (TYP)
CENTER STIFFENER
SPOT WELD (TYP)
SEE NOTE 3 HEREON
ELEVATION VIEW
N.T.S.
~--------"'L
SECTION TOP
14GA5MM
PERFORATED
SCREEN50%
OPEN
NOTES:
1. ALL MATERIALS ARE TYPE 304SS UNLESS
OTHERWISE NOTED
2. CENTER STIFFENER REQUIRED WHEN S 2: 3'-0 ..
3. CENTER STIFFENER WILL BE SPOT WELDED @ 4"
C.C. (Max) TO PERFORATED SCREEN
4. EXTENSION PANELS USED FOR UNEVEN CATCH
BASIN FLOOR
5. SCREENS LESS THAN 18" TALL WILL NOT INCLUDE
A CHANNEL AT MID-HEIGHT
. 66w
3/8" x 3 WEDGE
ANCHOR, 2 PER
CONNECTION (TYP)
5/16 .. X 1-1/8 ..
HEX BOLT, WASHER,
AND LOCK NUT
(TYP)
SECTION A-A
N.T.S .
L.06.oNOB.flOOOJlm'......::w.::illl(8 ·-□---IIOlEO
8 :mc,t.LCUlATIONI
.50 ADS FLEXSTORM
CPS U EXT
*SEE APPENDIX APPENDIX
A-1 AND CPS SIZING TABLE
FOR Hb, Hs, & L VALUES
VIEW N.T.S.
VIEWN-N
TOP AND BOTTOM
SCREEN BEND PROFILE
VIEWC-C
PLAN, ELEVATION, AND DETAIL
N.T.S.
Mn
1f22f2020
!!H~ET 1 Cll' I
-B
D
C
B
A
Page | 15
•Hs
2"
(Typ.)
0
0
Horizontal
1 /4" X 1/2" X 1/2"
12GA U-Channel
Stiffener (Typ.)
I •Hb
2"
(Typ.)
Vertical
1 1/4" X 1/2" X 1/2"
12GA U-Channel
Stiffener (Typ.)
ELEVATION VIEW
N.T.S.
R=10"
(Typ.) I
Spot Weld (Typ.)
See Note 2
Hereon
1 1/2" X 1 1/2"
13GA Mounting
Bracket (Typ.)
--------14GA 5m m Perforated Screen
50% Open
NOTES:
1. All Materials Are Type 304SS Unless Otherwise Noted
2. All Horizontal And Vertical Stiffeners Shall Be Spot
Welded @ 4"C.C. (Max) To Perforated Screen
3. For Catch Basin Uneven Floor Extension Panel Detail
See Sh. 3
3/8" X 3"
Wedge Anchor,
2 Per Connection (Typ.)
Ex. Catch
Basin Wall
1 1/2" X 1 1/2" X "Hs"
13GA Mounting
Bracket (Typ.)
3/4" (Typ }
14GA 5mm Perforated
Screen 50% Open I I I I I I I
1 1/4" X 1/2" X 1/2"
12GA U-Channel
Stiffener (Typ,) DETAIL A
N.T.S.
Ver!Jcal
PLAN VIEW
N.T.S.
1 1/4" x 1/2" x 1/2" 12GA U-Channel
S iffener (Typ.)
....----..... / ,, I \ / \
1 1/2" X 1 1/2"
13GA
Mounting
Bracket
---·
ADS FLEXSTORM
CPS U
PLAN, ELEVATION, AND
DETAIL
All Materials Ive Type 304SS Unless Otherwise Noted
2 All Honzontal And Vertical Stiffeners Shall Be Spot
Welded@ 4"C.C. (Max} To Perforated Screen
3 Center Stiffener Required When
S 2: 3'-0"
4. Top And Center Base Support Brackets Required
When S 2: 3'-0"
5. 3" Base Support Bracket At The In ecbon Point
Required For All Units
6. For Catch Basin Uneven Floor Extension Panel Detail
See Sh 4
' ' (Typ.)
[
5/16" x 1· Hex Bolt,
Washer, And Lock Nut,
2 Per Connection 3" Base Support\',..___ __ ...,(12" Center Base Support
Bracket ("!YP ), Bracket (When S 2: 3'-0") 1 1/4" X 1/2" X 1/2" -/l.__
12GA U-Channel\ i V i See Oetatl 0, Sh. 3 See Detail C, Sh 3
Top Support
Bracket,
See Sh. 2
ELEVATION VIEW
NT.S
3/8" X 3"
Wedge Anchor
{Typ.)
----------•L __________ _,,
PLAN VIEW
N.T.S.
Stiffener {Typ.) 1 I I 3/4"
J..---'---l...:..---.1' (Typ.) !
14GA5mm
Perforated
Screen 50%
Open
1 1/2" x 1 1/2" x "Hs"
13GA Mounting
Bracket (Typ.)
See Detail A
Hereon
I
2" I
(Typ.) 7 I I I
~318"x3"
Ex. Catch I Wedge Anchor,
Basin Wall 1 2 Per Connection
DETAIL A
N.T.S.
I (Typ.)
--'
ADS FLEXSTORM
CPSL
PLAN. ELEVATION, ANO
Page | 16
Appendix C. Extension Panel Work Instructions
EXTENSION PANEL WORK INSTRUCTIONS
Use a grinding wheel to cut the panel after
scribing the pattern of the floor on the top
portion of t he panel. Cut the pattern out and
now reverse it for installation.
Use provided S the extension panel to t he
CPS. For Quick angle may be placed
behind the sere ills more than a 2" gap.
For standard ins t anchored into the floor
To scribe the basin floor pattern onto the extension panel use a spacer or our scribing tool as show n. Run the tool along the basin floor
with a marker scribing the contour on the top portion of the extension panel. Cut the line off w ith a portable cutoff grindi ng tool.
Reverse the panel cut side dow n w hich should match the flooring contour perfectly. Install the tek screw s on the top portion of the
extension panel connecting it to the main CPS screen.
Page | 17
14GA 5mm Perforated
Screen 50% Open
Z" x 'Z' x 3--14GA5mm
P"rforated Base Support
Bracket
Ex Catch
Basin Floor
A
7
EXTENSION PANEL WORK INSTRUCTIONS
ELEVATION VIEW
N.T.S.
1 Piece ExtenstOn
Panel 14GA 5mm
Perforated Screen
50%0pen
1 1/2" x 1 1/2" 13GA
Mounting Bracket (Typ.)
See Detail A,
Sh. 1 (Typ.)
Extension Pa~ Scribed To
Conform To Catch Basin Floor
1 Piece Extension Panel
14GA 5mm Perforated
Screen 500/. Open
3116" Self Drillng screw (Typ.)
SECTION A-A
N.T.S.
14GA 5rm1 Perforated
Screen 50% Open
Horizontal 1 114• x 1/2'" x 1/2"
12GA U.Channet Stiffener
ADS FLEXSTORM
CPS U
EXTENSION PANEL DETAILS
Page | 18
Appendix D. Photo Gallery
Hinged Lid Installation Photos
Page | 19
4lOSO'SFIEl.DPHOTOS
llEFOlll •lld.AITUI MAJ,._'ltlUf,;Q
Page | 20
Appendix E. Vector Control Drawing Showing Hinged Lid
CPS HINGED LID FOR VECTOR CONTROL
HINGED LID SHOWN IN OPEN POSmON
(REMAINS IN OPEN POSmON ON ITS OWN)
LID BRACKETS SEOJRED TO
WALL WITH SS WEDGE ANCHORS
STAINLESS STEEL HINGE WELDED
TO LID AT EAQ-1 SUPPORT BRACKET
= -Tin: IIWIGIO --c CPS CONNECTOR PIPE ~ A ~ ... -.:.:..
Page | 21
APPENDIX F. ADS CPS Load Testing
ADS CPS LOAD TESTING
Uniform water loading results in 54 lbs/sqft against a solid screen. Triangular load distribution over an 18" tall screen results in 94 lbs/sqft along
the bottom edge and tapers off to zero at the very top of the screen. LA County has asked us to simulate this triangular load scenario as trash
builds up along the bottom and blinds the lower portion of the screen. We used steel bundles of channel that measured 6" x 8" and weighed 18
lbs each. 3 bundles make up 1 sqft at exactly 54 lbs or 54 lbs /sqft If we orientate the bundles to create 2 rows each 8" tall side by side, then we
can create an 8" tall load of 108 lbs/sqft by stacking 2 bundles high on the bottom and 54 lbs/sqft in a single layer on the top. This provides a fairly
significant safety factor vs the real world triangular load distribution. We proceeded with this loading scenario on a 10' I ong continous screen in
our U-Extended configuration. The screen is rolled on 2 ends and a 7' straight length results across the mid section at 12" spacing from the wall.
We previously determined that the maximum straight length span for our screen is 42" before deflecting more than 1".
Test 1: We anchored the 10' continuous screen on a concrete floor at both ends and added two support brackets at 40" spacing centered on the
screen and anchored on the brick wall. We added the load stacking 2 bundles high on the bottom row and 1 bundle tall covering the entire screen
and witnessed minimal deflection if any. We continued loading adding additional bundles to the bottom load and also having 2 people stand in
the center of the screen witnessing minimal deflection less than 1/2".
Test 2: We ran another test on our 2 pc screen using only one l-bracket behind the connector located in the center of the 10' long screen
comprised of 2 separate 5' l -shaped screens. We duplicated the load scenario and once again saw no deflection. We captued the loading on video
which can be found at these dropbox links ..
https://www.dropbox.com/s/vaqz52zoacxsiie/Video%20Mar°/o2008%2C%203%2002%2053%20P M. mov?dl=0
https://www.dropbox.com/s/ysrtl 1 wa nyhzzqg/Video%20Mar%2008%2C%202%2043%2043%20PM .mov?dl=0
TEST 2 VIDEO
TEST 1 VIDEO
Page | 22
ADS CPS DEFLECTOR LOAD TESTING
U-BEND FRONT EDGE WITH 36" SUPPORT BRACKET SPACING
Wt continued ttstin& with I ntw dtfkctor that
included a U bend on the front edct. 1" drop i nd
1/2• bend under. The center1ine spacing on the
Support Brackets was once again 36". The results
were quite conclusive a.sour 22S lb test load
(worker) wu a bit to Jump up and down on 1 foot
at tdgt for scrttn without 1ny deformation. Wt
propose all deflectors will include tM double bend
on outer front ed;e for the continous lellJth. No
Edge Stiffener is required. We are asking for a
callout allowing 36" Max Allowabte Spacing
between any 2 Support Bru'kets.