HomeMy WebLinkAboutCT 2019-0002; MADISON FIVE; PRELIMINARY DRAINAGE REPORT AND STORM WATER STANDARD PROJECT REQUIREMENTS; 2019-01-17PRELIMINARY DRAINAGE REPORT AND STORM WATER STANDARD
PROJECT REQUIREMENTS
For
MADISON STREET & OAK ST. Southeast Corner of Madison St. & Oak St. Carlsbad, CA APN 204-031-01 & 204-031-02
January 17, 2019
Mel Landy, PE
PREPARED BY:
Jose Sanchez, PE
2888 LOKER AVENUE EAST, SUITE 217
CARLSBAD, CA 92010
(760) 929-2288
Hwl.
HOWES I WEILER I LANDY
PLANNING & ENGINEERING
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Madison Street & Oak Avenue
TABLE OF CONTENTS Project Vicinity Map
Introduction …………………………………………………………………….2
Existing Drainage Conditions…...…………………………………………….4 Proposed Drainage Conditions…...…………………………………………..4 Methodology ……...…………………………………………………………….4-7 Drainage Summary .……………………………………………………………8
Storm Water Quality Summary…………………………………………………8
Conclusions ………………………………………………………………………9 References ……………………………………………………………………….9
Appendix
1 Existing Conditions Calculations - Basin Map
2 Developed Conditions Calculations – Basin Map 3 Storm Water Standard Project Requirements 4 Maps and Charts, Weighted Runoff Coefficient Calc.
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Introduction
This Drainage Study for the proposed five-unit attached residential condominium building development for APN 204-031-01 and 204-034-02 has been prepared to analyze the hydrologic and hydraulic characteristics of the existing and proposed project site. This
report intends to present both the methodology and the calculations used for determining the runoff from the project site in both the pre-developed (existing) conditions and the post-developed (proposed) conditions produced by the 100-year, 6-hour storm. In addition, this report will propose the sizing of all necessary storm drain facilities and storm drain piping to safely convey the runoff, based on the 100-year rainfall event, per County of San Diego
Hydrology and Storm Drain Design Standards. Elevations range for the project site are approximately 54.0 feet above mean sea level (mls) in the south east corner of the site along the alley way to approximately 50.9 feet at the north west at the intersection of Madison street and Oak Avenue.
The project is within two separate legal lots, known as APN 201-031-01 and 204-031-02, Lot 15 and 16. The site is located on the southeast corner of Madison street and Oak Avenue, in the city of Carlsbad, consisting of approximately 0.18 Acres. Said lots are bordered on the North by Oak Avenue, on the east by an alley, on the west by Madison
Street and on the south by a single family residential property. See Vicinity Map Below. Project site is currently undeveloped and consists of a small shed at the northwest corner with fencing round the perimeter of the property. The vegetation within the site consist of
mature trees and palm trees on the eastern portion of the project.
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PROJECT VICINITY MAP
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Madison Street & Oak Avenue
Existing Drainage Conditions
Project site has a flat terrain with the high point of the site located on the south east corner
adjacent to the alley with terrain sloping on a north westerly direction towards the intersection of Oak Ave. and Madison street. The project site does not have any under ground drainage system to convey flows off site, flows leave the site along the westerly property line where they comingle with flows from Madison Street and Oak Avenue before
continuing a south westerly direction along Oak Avenue, until they enter an underground
conveyance system located approximately 550 feet from the project site. Eventually flows discharge into Buena Vista Lagoon. Proposed Drainage Conditions
The project proposes to create a five-unit multi-family residential site, with new impervious surfaces which consist of: attached garages, rooftops, walkways, and patio area. The site will include landscape areas within the frontage of Madison Street and Oak Avenue. There will be grading activities to level out areas for new improvements, but the drainage patterns
will remain the same.
The project proposes installation of raised planters for water quality purposes and storm drain systems that will convey flows to the same pre-development discharge points. Study Methodology
The method of analysis was based on the Rational Method according to the San Diego. Runoff calculations for this study were accomplished by using the Rational Method. The Rational Method is a physically-based numerical method where runoff is assumed to be directly proportional to rainfall and area, less losses for infiltration and depression storage.
Flows were computed based on the Rational formula: Q = CIA
Where Q = Peak discharge (cfs);
C = runoff coefficient, based on land use and soil type I = rainfall intensity (in/hr) A = watershed area (acre)
(1) Runoff Coefficient, C Table 4-1 lists the estimated coefficients for urban areas.
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Table 4-1
The runoff coefficient C for this site is calculated as follows pursuant to section 3.1.2 of the County Hydrology Manual. The runoff coefficient (C) represents the ratio of rainfall that runs off the watershed versus the portion that infiltrates to the soil. The runoff coefficient is dependent on the land use
coverage and soil type (Table 4-1). Adjustment have been made to accurately represent
the existing compacted rough graded condition. See appendix 3, for runoff coefficient calculations, which were prepared based on soil type and impervious percentage using the formula by the San Diego County Hydrology Manual
C = 0.90 × (% Impervious) + Cp × (1 - % Impervious) Where: 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 4 of the San Diego County
Hydrology Manual.
(2) Rainfall Intensity, I
Average rainfall intensity for a duration equal to the Tc for the area, in inches per hour.
The storm frequency for this study has a 100-year recurrence interval. The six-hour anticipated precipitation for the project site subject to the design storm frequency.
R -OFF ,ooEFFICIL"lT
(%) Hnhologiir Soi:l!Type
Ll\J"ID SE (County Eletm"nts) lmpE'I'!i". A B ,c D
Permanent Open Spare 020 0. s 0.30 0.35
Resiooitiial, 1.0 DU/A or fess: 10 027 0.32 o,.J6 0.41
Residential, 2 .0 D /A or fess 20 0 4 0.3:S 0.412 0.46
Residential, .9 D /A or fess 25 038 0.41 0.45 0.49
Residential, 4.3 DU/A or fess 30 0.41 0.45 0.48: 0.5_
Residential, .3 D /A or less 40 0.48 0.51 0.54 0.57
Residential, 10.9 DU/ . ..tl. or Jess, 5 0.52 0.54 0,.5 0.60
Residential, 14.5 D -/A or less, so 055 0.00 0.6,3
Residential, 24.0 D 7Aor Jess, 65 0.66 0.69 0. l
Resiooitiial, 3 .0 DU/A or Jess, 80 o: 6, o,.1s 0. 9
ei.ghl:!oJhiod CoD:llllelcial 80 0. 6, 0. 0. s: 0. 9
Ge:neraill Commerciaill 8.S 0.,80 0.81 0.82
Offi.ce Pro:fes&ionaYCo:mmerc ·.a1 90 o,. 0.85
limited Im.1e.1rial 90 0.84 0.85
Ge:neraill lmM:riaill 95 o,_g7 0.87
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P6 = 2.55 in P24 = 4.5 in P6 is in the range of 45% to 65% of P24 and therefore doesn’t need to be adjusted.
The RM equation assumes that the storm event being analyzed delivers precipitation to the entire basin uniformly, and therefore the peak discharge rate will occur when a raindrop falls at the most remote portion of the basin arrives at the point of analysis. The RM also assumes that the fraction of rainfall that becomes runoff or the runoff coefficient C is not
affected by the storm intensity, I, or the precipitation zone number.
(1) Time of Concentration, Tc The time of concentration is the time required for runoff to flow from the most remote part
of the watershed to the outlet point under consideration.
The time of concentration for each sub-area on site, Tc is determined from the following formula (San Diego County Hydrology Manual, dated June 2003) with the initial lengths and times adjusted per Table 3-2 of the Manual for slope and land use.
There is an illustration of this formula in Figure 2, which is per County 2003 Hydrology
Manual. Time of concentration (TC) is composed of two components: The initial time of
T, = l .B(l. ~C)✓D (For overland time of flow)
'S
Where,
T, = Time of Concentration (hours)
D = Watercourse Distance (ft)
S= Slope(%)
C = Runoff Coefficient
( l 1.9 Ll )O.lSS T = --' M (For natural watersheds)!
Where,
T~ = Time of Concentration in hours (hou rs)
L = Watercourse Distance (miles)
M = Change in elevation along effective slope line (ft)
The average rainfall intensity is ca lculated from the following equation (San Diego County
Hydrology Manual, June 2003)
Where,
I = Rainfa ll Intensity (in/hr)
P6 = Six hour precipitation (inches)
D = Duration (min.)
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concentration (Ti ), and the travel time (Tt ).
The maximum overland flow length (LM ) is used from Table 4 in calculating the initial time
of concentration. The source for this chart is the San Diego County Hydrology Manual
(Table 3.2), June 2003.
In addition to the above Ration Method assumptions, the conservative assumption that all runoff coefficients utilized for this report are based on Type “B”
The County of San Diego Rational Method program within CivilDesign was utilized in
calculating runoff for all basins smaller than 0.5 square miles in size.
Table 4 • Maximum Overland Flow Length (LM) & Initial Time of Concentration (T;)
Element DU/ 0.50% 1% 2% 3% 5% 10%
Acre LM Ti LM Ti LM Ti LM Ti LM Ti LM Ti
Natural 50 13.2 70 12.5 85 10.9 100 10.3 100 8.7 100 6.9
LDR 1 50 12.2 70 115 85 10.0 100 9.5 100 8.0 100 6.4
LDR 2 50 113 70 10.5 85 9.2 100 8.8 100 7.4 100 5.8
LDR 2.9 50 103.0 70 10.0 85 8.8 95 8.1 100 7.0 100 5.6
J:,,IDR 4.3 50 10.2 70 9.6 80 8.1 95 7.8 100 6.7 100 5.3
J:,,IDR 7.3 50 9.2 65 8.4 80 7.4 95 7.0 100 6.0 100 4.8
J:,,IDR 10.9 50 8.7 65 7.9 80 6.9 90 6.4 100 5.7 100 4.5
J:,,IDR 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
OP/Com 50 410 60 3.7 70 3.1 80 2.9 90 2.6 100 2.2
Limited ! 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 19
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Drainage Summary Upon performing hydrologic analysis of the project site in both the proposed developed and existing condition, the following results were produced:
Table 1 - Summary of existing conditions
BASIN / Node Effective C Tc (min.) I in/hr Area (ac) Total Qpeak (cfs) Total
A / 15 0.27 11.6 3.91 0.18 0.19
Total -- -- -- 0.18 0.19
Table 2 – Summary of developed conditions BASIN / Node Effective C Tc (min.) I in/hr Area (ac) Total Qpeak (cfs) Total
A /17 0.78 4.05 6.72 0.11 0.58
B/30 0.71 5.73 6.15 0.07 0.31
TOTAL -- -- -- 0.18 0.84
As shown on tables above, there will be an increase in a 100-year storm event in the proposed condition of 0.65 CFS.
Storm water Quality Summary
This project has been determined to be a “Standard Project” per the City of Carlsbad Storm Water Standards Questionnaire (E-34) and is therefore exempt from priority project requirements. The development proposes to reduce the discharge of pollutants offsite by
utilizing source control and Site Design Low Impact Development (LID) BMP’s to the
maximum extent possible. The project proposed landscaping and ground cover along the frontage of Madison Street and Oak Avenue. Roof downspouts will convey flows to eight (8) total planters within the
project site. Five (5) raised planters are fronting Oak Avenue, two (2) raised planters
fronting Madison Street, and one (1) ground planter is located at the south east corner of unit 3, which will be constructed with impermeable liner around the perimeter and along portion of unit 3 foundation (acting as a cutoff wall) to avoid lateral migration of infiltration under the building. Said planters will discharge flows via curb outlets at the
predevelopment discharge point.
As shown in Table 1 and Table 2, the project has increase peak flows in the unmitigated 100-year storm condition, therefor the proposed planters will be utilized to mitigate the increase runoff.
The raised planters will be integrated with the landscape design to provide treatment to storm water runoff generated on-site before discharging runoff in a control manner.
I I
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Conclusions
The proposed storm drain system was designed in accordance with the guidelines set by
the County of San Diego. During the design of the proposed drainage systems precautions were taken to limit adverse downstream affects and to maintain existing drainage characteristics wherever possible.
A summary of the facts and findings associated with this project and the measures
addressed by this report is as follows:
• The project will not significantly alter drainage patterns on the site.
• The ultimate discharge points will not be changed.
• Graded areas and slopes will be landscaped to reduce or eliminate sediment
discharge.
• The storm drain system for the project is designed to route and convey all resulting runoff from developed conditions to the existing points of discharge.
References
"San Diego County Hydrology Manual", revised June 2003, County of San Diego,
Department of Public Works, Flood Control Section.
"California Regional Water Quality Control Board Order No. 2001-07," California Regional
Water Control Board, San Diego Region (SDRWQCB).
“City of Carlsbad BMP Design Manual” February 2016, Edition
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APPENDIX 1 Existing Conditions Calculations & Drainage Map
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HOWES I WEILER I LANDY
PLANNING & ENGINEERING DATE:
Tel. 760.929.2288 Fax. 760.929.2287
2888 LOKER AVENUE EAST SUITE 217
CARLSBAD, CA 92010
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DRAWING:
1 /17 /19 SHEET 1 OF 1
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Madison Street & Oak Avenue
San Diego County Rational Hydrology Program
CIVILCADD/CIVILDESIGN Engineering Software,(c)1991-2009 Version 7.8 Rational method hydrology program based on
San Diego County Flood Control Division 2003 hydrology manual Rational Hydrology Study Date: 12/11/18 ------------------------------------------------------------------------
Oak Ave. & Madison St. Pre-Development Condition 100-Year Storm Event
------------------------------------------------------------------------ ********* Hydrology Study Control Information ********** ------------------------------------------------------------------------ Program License Serial Number 6290
------------------------------------------------------------------------ Rational hydrology study storm event year is 100.0
English (in-lb) input data Units used Map data precipitation entered:
6 hour, precipitation(inches) = 2.550 24 hour precipitation(inches) = 4.500 P6/P24 = 56.7%
San Diego hydrology manual 'C' values used ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 5.000 to Point/Station 10.000 **** INITIAL AREA EVALUATION **** ______________________________________________________________________
Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 1.000 Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.000 [UNDISTURBED NATURAL TERRAIN ] (Permanent Open Space )
Impervious value, Ai = 0.000 Sub-Area C Value = 0.250 Initial subarea total flow distance = 50.000(Ft.)
Highest elevation = 53.800(Ft.) Lowest elevation = 52.900(Ft.) Elevation difference = 0.900(Ft.) Slope = 1.800 %
INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: The maximum overland flow distance is 85.00 (Ft) for the top area slope value of 1.80 %, in a development type of
Permanent Open Space In Accordance With Figure 3-3 Initial Area Time of Concentration = 11.60 minutes
TC = [1.8*(1.1-C)*distance(Ft.)^.5)/(% slope^(1/3)] TC = [1.8*(1.1-0.2500)*( 85.000^.5)/( 1.800^(1/3)]= 11.60 Rainfall intensity (I) = 3.905(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for area (Q=KCIA) is C = 0.250
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Subarea runoff = 0.039(CFS) Total initial stream area = 0.040(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 10.000 to Point/Station 15.000 **** SUBAREA FLOW ADDITION ****
______________________________________________________________________ Rainfall intensity (I) = 3.905(In/Hr) for a 100.0 year storm User specified 'C' value of 0.270 given for subarea
Time of concentration = 11.60 min. Rainfall intensity = 3.905(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.266 CA = 0.048 Subarea runoff = 0.148(CFS) for 0.140(Ac.) Total runoff = 0.187(CFS) Total area = 0.180(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 15.000 to Point/Station 15.000
**** CONFLUENCE OF MINOR STREAMS **** ______________________________________________________________________ Along Main Stream number: 1 in normal stream number 1
Stream flow area = 0.180(Ac.) Runoff from this stream = 0.187(CFS) Time of concentration = 11.60 min.
Rainfall intensity = 3.905(In/Hr) Summary of stream data:
Stream Flow rate TC Rainfall Intensity No. (CFS) (min) (In/Hr)
1 0.187 11.60 3.905 Qmax(1) = 1.000 * 1.000 * 0.187) + = 0.187
Total of 1 streams to confluence: Flow rates before confluence point:
0.187 Maximum flow rates at confluence using above data: 0.187
Area of streams before confluence: 0.180 Results of confluence:
Total flow rate = 0.187(CFS) Time of concentration = 11.596 min. Effective stream area after confluence = 0.180(Ac.)
End of computations, total study area = 0.180 (Ac.)
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Madison Street & Oak Avenue
APPENDIX 2
Developed Conditions Calculations & Drainage Map
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HOWES I WEILER I LANDY
PLANNING & ENGINEERING
Tel. 760.929.2288 Fax. 760.929.2287
10 0 20 40 60 2888 LOKER AVENUE EAST SUITE 217
CARLSBAD, CA 92010
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01 /17 /19 SHEET 1 OF 1
Page | 14 of 77 DRAINAGE REPORT
Madison Street & Oak Avenue
San Diego County Rational Hydrology Program CIVILCADD/CIVILDESIGN Engineering Software,(c)1991-2009 Version 7.8 Rational method hydrology program based on
San Diego County Flood Control Division 2003 hydrology manual Rational Hydrology Study Date: 01/17/19 ------------------------------------------------------------------------
Oak ave and Madison Street Post-Development 100-Year Storm Event
------------------------------------------------------------------------ ********* Hydrology Study Control Information **********
------------------------------------------------------------------------ Program License Serial Number 6290 ------------------------------------------------------------------------ Rational hydrology study storm event year is 100.0 English (in-lb) input data Units used Map data precipitation entered:
6 hour, precipitation(inches) = 2.550 24 hour precipitation(inches) = 4.500 P6/P24 = 56.7%
San Diego hydrology manual 'C' values used
BASIN A
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 5.000 to Point/Station 10.000
**** INITIAL AREA EVALUATION **** A.1____________________________________________________________________ Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 1.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.000
[INDUSTRIAL area type ] (Limited Industrial ) Impervious value, Ai = 0.900
Sub-Area C Value = 0.840 Initial subarea total flow distance = 50.000(Ft.) Highest elevation = 53.500(Ft.)
Lowest elevation = 52.750(Ft.) Elevation difference = 0.750(Ft.) Slope = 1.500 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS:
The maximum overland flow distance is 70.00 (Ft) for the top area slope value of 1.50 %, in a development type of Limited Industrial
In Accordance With Figure 3-3 Initial Area Time of Concentration = 3.42 minutes TC = [1.8*(1.1-C)*distance(Ft.)^.5)/(% slope^(1/3)]
TC = [1.8*(1.1-0.8400)*( 70.000^.5)/( 1.500^(1/3)]= 3.42 Calculated TC of 3.421 minutes is less than 5 minutes, resetting TC to 5.0 minutes for rainfall intensity calculations
Rainfall intensity (I) = 6.719(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.840 Subarea runoff = 0.226(CFS)
Total initial stream area = 0.040(Ac.)
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++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 10.000 to Point/Station 15.000 **** SUBAREA FLOW ADDITION **** A.2____________________________________________________________________
Calculated TC of 3.421 minutes is less than 5 minutes, resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) = 6.719(In/Hr) for a 100.0 year storm
User specified 'C' value of 0.790 given for subarea Time of concentration = 3.42 min. Rainfall intensity = 6.719(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area (Q=KCIA) is C = 0.810 CA = 0.081 Subarea runoff = 0.318(CFS) for 0.060(Ac.)
Total runoff = 0.544(CFS) Total area = 0.100(Ac.) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 10.000 to Point/Station 15.000 **** PIPEFLOW TRAVEL TIME (User specified size) **** ______________________________________________________________________
Upstream point/station elevation = 50.590(Ft.) Downstream point/station elevation = 49.850(Ft.) Pipe length = 105.00(Ft.) Slope = 0.0070 Manning's N = 0.012
No. of pipes = 1 Required pipe flow = 0.544(CFS) Given pipe size = 6.00(In.) NOTE: Normal flow is pressure flow in user selected pipe size.
The approximate hydraulic grade line above the pipe invert is 0.280(Ft.) at the headworks or inlet of the pipe(s) Pipe friction loss = 0.841(Ft.)
Minor friction loss = 0.179(Ft.) K-factor = 1.50 Pipe flow velocity = 2.77(Ft/s) Travel time through pipe = 0.63 min.
Time of concentration (TC) = 4.05 min. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 17.000 to Point/Station 17.000 **** SUBAREA FLOW ADDITION **** A.3___________________________________________________________________ Calculated TC of 4.052 minutes is less than 5 minutes, resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) = 6.719(In/Hr) for a 100.0 year storm User specified 'C' value of 0.540 given for subarea Time of concentration = 4.05 min. Rainfall intensity = 6.719(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.785 CA = 0.086 Subarea runoff = 0.036(CFS) for 0.010(Ac.) Total runoff = 0.580(CFS) Total area = 0.110(Ac.) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 17.000 to Point/Station 17.000 **** CONFLUENCE OF MINOR STREAMS **** ______________________________________________________________________
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Madison Street & Oak Avenue
Along Main Stream number: 1 in normal stream number 1 Stream flow area = 0.110(Ac.) Runoff from this stream = 0.580(CFS)
Time of concentration = 4.05 min. Rainfall intensity = 6.719(In/Hr) Summary of stream data:
Stream Flow rate TC Rainfall Intensity No. (CFS) (min) (In/Hr)
1 0.580 4.05 6.719 Qmax(1) = 1.000 * 1.000 * 0.580) + = 0.580
Total of 1 streams to confluence: Flow rates before confluence point: 0.580
Maximum flow rates at confluence using above data: 0.580 Area of streams before confluence:
0.110 Results of confluence: Total flow rate = 0.580(CFS)
Time of concentration = 4.052 min. Effective stream area after confluence = 0.110(Ac.)
BASIN B
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 20.000 to Point/Station 25.000 **** INITIAL AREA EVALUATION **** B.1____________________________________________________________________
Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 1.000 Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.000 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.670 Initial subarea total flow distance = 50.000(Ft.)
Highest elevation = 53.300(Ft.) Lowest elevation = 52.300(Ft.) Elevation difference = 1.000(Ft.) Slope = 2.000 %
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 = 5.73 minutes TC = [1.8*(1.1-C)*distance(Ft.)^.5)/(% slope^(1/3)] TC = [1.8*(1.1-0.6700)*( 75.000^.5)/( 1.600^(1/3)]= 5.73 Rainfall intensity (I) = 6.153(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.670 Subarea runoff = 0.082(CFS)
Total initial stream area = 0.020(Ac.)
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Page | 17 of 77 DRAINAGE REPORT
Madison Street & Oak Avenue
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 25.000 to Point/Station 30.000 **** SUBAREA FLOW ADDITION **** B.2____________________________________________________________________
Rainfall intensity (I) = 6.153(In/Hr) for a 100.0 year storm User specified 'C' value of 0.730 given for subarea Time of concentration = 5.73 min.
Rainfall intensity = 6.153(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.713 CA = 0.050
Subarea runoff = 0.225(CFS) for 0.050(Ac.) Total runoff = 0.307(CFS) Total area = 0.070(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 35.000 to Point/Station 35.000 **** CONFLUENCE OF MINOR STREAMS ****
______________________________________________________________________ Along Main Stream number: 1 in normal stream number 2 Stream flow area = 0.070(Ac.)
Runoff from this stream = 0.307(CFS) Time of concentration = 5.73 min. Rainfall intensity = 6.153(In/Hr)
Summary of stream data: Stream Flow rate TC Rainfall Intensity
No. (CFS) (min) (In/Hr)
1 0.580 4.05 6.719 2 0.307 5.73 6.153 Qmax(1) =
1.000 * 1.000 * 0.580) + 1.000 * 0.707 * 0.307) + = 0.798 Qmax(2) =
0.916 * 1.000 * 0.580) + 1.000 * 1.000 * 0.307) + = 0.839
Total of 2 streams to confluence: Flow rates before confluence point: 0.580 0.307
Maximum flow rates at confluence using above data: 0.798 0.839 Area of streams before confluence:
0.110 0.070 Results of confluence: Total flow rate = 0.839(CFS)
Time of concentration = 5.731 min. Effective stream area after confluence = 0.180(Ac.) End of computations, total study area = 0.180 (Ac.)
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Page | 18 of 77 DRAINAGE REPORT
Madison Street & Oak Avenue
APPENDIX 3
Storm Water Standard Project Requirements
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E-34 Page 1 of 4 REV 02/16
Development Services
Land Development Engineering
1635 Faraday Avenue
(760) 602-2750
www.carlsbadca.gov
STORM WATER STANDARDS
QUESTIONNAIRE
E-34
INSTRUCTIONS:
To address post-development pollutants that may be generated from development projects, the city requires that new
development and significant redevelopment priority projects incorporate Permanent Storm Water Best Management
Practices (BMPs) into the project design per Carlsbad BMP Design Manual (BMP Manual). To view the BMP Manual,
refer to the Engineering Standards (Volume 5).
This questionnaire must be completed by the applicant in advance of submitting for a development application
(subdivision, discretionary permits and/or construction permits). The results of the questionnaire determine the level of
storm water standards that must be applied to a proposed development or redevelopment project. Depending on the
outcome, your project will either be subject to ‘STANDARD PROJECT’ requirements or be subject to ‘PRIORITY
DEVELOPMENT PROJECT’ (PDP) requirements.
Your responses to the questionnaire represent an initial assessment of the proposed project conditions and impacts. City
staff has responsibility for making the final assessment after submission of the development application. If staff
determines that the questionnaire was incorrectly filled out and is subject to more stringent storm water standards than
initially assessed by you, this will result in the return of the development application as incomplete. In this case, please
make the changes to the questionnaire and resubmit to the city.
If you are unsure about the meaning of a question or need help in determining how to respond to one or more of the
questions, please seek assistance from Land Development Engineering staff.
A completed and signed questionnaire must be submitted with each development project application. Only one
completed and signed questionnaire is required when multiple development applications for the same project are
submitted concurrently.
PROJECT INFORMATION
PROJECT NAME: PROJECT ID:
ADDRESS: APN:
The project is (check one): New Development Redevelopment
The total proposed disturbed area is: ________ ft2 (________) acres
The total proposed newly created and/or replaced impervious area is: ________ ft2 (________) acres
If your project is covered by an approved SWQMP as part of a larger development project, provide the project ID and the
SWQMP # of the larger development project:
Project ID SWQMP #:
Then, go to Step 1 and follow the instructions. When completed, sign the form at the end and submit this with your
application to the city.
X
7,929 0.18
201-031-01-00 AND 204-031-02-00Southeast corner of Madison Street and Oak Avenue
Oak Ave. & Madison St.
6,088 0.14
C cityof
Carlsbad
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E-34 Page 2 of 4 REV 04/17
STEP 1
TO BE COMPLETED FOR ALL PROJECTS
To determine if your project is a “development project”, please answer the following question:
YES NO
Is your project LIMITED TO routine maintenance activity and/or repair/improvements to an existing building
or structure that do not alter the size (See Section 1.3 of the BMP Design Manual for guidance)?
If you answered “yes” to the above question, provide justification below then go to Step 5, mark the third box stating “my
project is not a ‘development project’ and not subject to the requirements of the BMP manual” and complete applicant
information.
Justification/discussion: (e.g. the project includes only interior remodels within an existing building):
If you answered “no” to the above question, the project is a ‘development project’, go to Step 2.
STEP 2
TO BE COMPLETED FOR ALL DEVELOPMENT PROJECTS
To determine if your project is exempt from PDP requirements pursuant to MS4 Permit Provision E.3.b.(3), please answer
the following questions:
Is your project LIMITED to one or more of the following:
YES NO
1.Constructing new or retrofitting paved sidewalks, bicycle lanes or trails that meet the following criteria:
a)Designed and constructed to direct storm water runoff to adjacent vegetated areas, or other non-
erodible permeable areas;
b)Designed and constructed to be hydraulically disconnected from paved streets or roads;
c)Designed and constructed with permeable pavements or surfaces in accordance with USEPA
Green Streets guidance?
2.Retrofitting or redeveloping existing paved alleys, streets, or roads that are designed and constructed in
accordance with the USEPA Green Streets guidance?
3.Ground Mounted Solar Array that meets the criteria provided in section 1.4.2 of the BMP manual?
If you answered “yes” to one or more of the above questions, provide discussion/justification below, then go to Step 5, mark
the second box stating “my project is EXEMPT from PDP …” and complete applicant information.
Discussion to justify exemption ( e.g. the project redeveloping existing road designed and constructed in accordance with
the USEPA Green Street guidance):
If you answered “no” to the above questions, your project is not exempt from PDP, go to Step 3.
X
X
X
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E-34 Page 3 of 4 REV 04/17
STEP 3
TO BE COMPLETED FOR ALL NEW OR REDEVELOPMENT PROJECTS
To determine if your project is a PDP, please answer the following questions (MS4 Permit Provision E.3.b.(1)):
YES NO
1.Is your project a new development that creates 10,000 square feet or more of impervious surfaces
collectively over the entire project site? This includes commercial, industrial, residential, mixed-use,
and public development projects on public or private land.
2.Is your project a redevelopment project creating and/or replacing 5,000 square feet or more of
impervious surface collectively over the entire project site on an existing site of 10,000 square feet or
more of impervious surface? This includes commercial, industrial, residential, mixed-use, and public
development projects on public or private land.
3.Is your project a new or redevelopment project that creates and/or replaces 5,000 square feet or more
of impervious surface collectively over the entire project site and supports a restaurant? A restaurant is
a facility that sells prepared foods and drinks for consumption, including stationary lunch counters and
refreshment stands selling prepared foods and drinks for immediate consumption (Standard Industrial
Classification (SIC) code 5812).
4.Is your project a new or redevelopment project that creates 5,000 square feet or more of impervious
surface collectively over the entire project site and supports a hillside development project? A hillside
development project includes development on any natural slope that is twenty-five percent or greater.
5.Is your project a new or redevelopment project that creates and/or replaces 5,000 square feet or more
of impervious surface collectively over the entire project site and supports a parking lot? A parking lot is
a land area or facility for the temporary parking or storage of motor vehicles used personally for
business or for commerce.
6.Is your project a new or redevelopment project that creates and/or replaces 5,000 square feet or more
of impervious street, road, highway, freeway or driveway surface collectively over the entire project
site? A street, road, highway, freeway or driveway is any paved impervious surface used for the
transportation of automobiles, trucks, motorcycles, and other vehicles.
7.Is your project a new or redevelopment project that creates and/or replaces 2,500 square feet or more
of impervious surface collectively over the entire site, and discharges directly to an Environmentally
Sensitive Area (ESA)? “Discharging Directly to” includes flow that is conveyed overland a distance of
200 feet or less from the project to the ESA, or conveyed in a pipe or open channel any distance as an
isolated flow from the project to the ESA (i.e. not commingled with flows from adjacent lands).*
8.Is your project a new development or redevelopment project that creates and/or replaces 5,000 square
feet or more of impervious surface that supports an automotive repair shop? An automotive repair
shop is a facility that is categorized in any one of the following Standard Industrial Classification (SIC)
codes: 5013, 5014, 5541, 7532-7534, or 7536-7539.
9.Is your project a new development or redevelopment project that creates and/or replaces 5,000 square
feet or more of impervious area that supports a retail gasoline outlet (RGO)? This category includes
RGO’s that meet the following criteria: (a) 5,000 square feet or more or (b) a project Average Daily
Traffic (ADT) of 100 or more vehicles per day.
10.Is your project a new or redevelopment project that results in the disturbance of one or more acres of land
and are expected to generate pollutants post construction?
11.Is your project located within 200 feet of the Pacific Ocean and (1) creates 2,500 square feet or more of
impervious surface or (2) increases impervious surface on the property by more than 10%? (CMC
21.203.040)
If you answered “yes” to one or more of the above questions, your project is a PDP. If your project is a redevelopment
project, go to step 4. If your project is a new project, go to step 5, check the first box stating “My project is a PDP …”
and complete applicant information.
If you answered “no” to all of the above questions, your project is a ‘STANDARD PROJECT.’ Go to step 5, check the
second box stating “My project is a ‘STANDARD PROJECT’…” and complete applicant information.
X
X
X
X
X
X
X
X
X
X
X
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E-34 Page 4 of 4 REV 04/17
STEP 4
TO BE COMPLETED FOR REDEVELOPMENT PROJECTS THAT ARE PRIORITY DEVELOPMENT PROJECTS (PDP)
ONLY
Complete the questions below regarding your redevelopment project (MS4 Permit Provision E.3.b.(2)):
YES NO
Does the redevelopment project result in the creation or replacement of impervious surface in an amount
of less than 50% of the surface area of the previously existing development? Complete the percent
impervious calculation below:
Existing impervious area (A) = __________________________ sq. ft.
Total proposed newly created or replaced impervious area (B) = _________________________sq. ft.
Percent impervious area created or replaced (B/A)*100 = __________%
If you answered “yes”, the structural BMPs required for PDP apply only to the creation or replacement of impervious
surface and not the entire development. Go to step 5, check the first box stating “My project is a PDP …” and complete
applicant information.
If you answered “no,” the structural BMP’s required for PDP apply to the entire development. Go to step 5, check the
check the first box stating “My project is a PDP …” and complete applicant information.
STEP 5
CHECK THE APPROPRIATE BOX AND COMPLETE APPLICANT INFORMATION
My project is a PDP and must comply with PDP stormwater requirements of the BMP Manual. I understand I must
prepare a Storm Water Quality Management Plan (SWQMP) for submittal at time of application.
My project is a ‘STANDARD PROJECT’ OR EXEMPT from PDP and must only comply with ‘STANDARD PROJECT’
stormwater requirements of the BMP Manual. As part of these requirements, I will submit a “Standard Project
Requirement Checklist Form E-36” and incorporate low impact development strategies throughout my project.
Note: For projects that are close to meeting the PDP threshold, staff may require detailed impervious area calculations
and exhibits to verify if ‘STANDARD PROJECT’ stormwater requirements apply.
My Project is NOT a ‘development project’ and is not subject to the requirements of the BMP Manual.
Applicant Information and Signature Box
Applicant Name: Applicant Title:
Applicant Signature: Date:
* Environmentally Sensitive Areas include but are not limited to all Clean Water Act Section 303(d) impaired water bodies; areas designated as Areas of Special Biological Significance by the State Water Resources Control Board (Water Quality Control Plan for the San Diego Basin (1994) and amendments); water bodies
designated with the RARE beneficial use by the State Water Resources Control Board (Water Quality Control Plan for the San Diego Basin (1994) and
amendments); areas designated as preserves or their equivalent under the Multi Species Conservation Program within the Cities and County of San Diego; Habitat
Management Plan; and any other equivalent environmentally sensitive areas which have been identified by the City.
This Box for City Use Only
City Concurrence:
YES NO
By:
Date:
Project ID:
X
OwnerDk Realty Holdings
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E-36 Page 1 of 4 Revised 09/16
Development Services
Land Development Engineering
1635 Faraday Avenue
(760) 602-2750
www.carlsbadca.gov
STANDARD PROJECT
REQUIREMENT
CHECKLIST
E-36
Project Information
Project Name:
Project ID:
DWG No. or Building Permit No.:
Source Control BMPs
All development projects must implement source control BMPs SC-1 through SC-6 where applicable and feasible. See
Chapter 4 and Appendix E.1 of the BMP Design Manual (Volume 5 of City Engineering Standards) for information to
implement source control BMPs shown in this checklist.
Answer each category below pursuant to the following.
"Yes" means the project will implement the source control BMP as described in Chapter 4 and/or Appendix E.1 of the
Model BMP Design Manual. Discussion/justification is not required.
"No" means the BMP is applicable to the project but it is not feasible to implement. Discussion/justification must be
provided. Please add attachments if more space is needed.
"N/A" means the BMP is not applicable at the project site because the project does not include the feature that is
addressed by the BMP (e.g., the project has no outdoor materials storage areas). Discussion/justification may be
provided.
Source Control Requirement Applied?
SC-1 Prevention of Illicit Discharges into the MS4 Yes No N/A
Discussion/justification if SC-1 not implemented:
SC-2 Storm Drain Stenciling or Signage Yes No N/A
Discussion/justification if SC-2 not implemented:
SC-3 Protect Outdoor Materials Storage Areas from Rainfall, Run-On, Runoff, and Wind
Dispersal Yes No N/A
Discussion/justification if SC-3 not implemented:
C cityof
Carlsbad
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E-36 Page 2 of 4 Revised 09/16
Source Control Requirement (continued) Applied?
SC-4 Protect Materials Stored in Outdoor Work Areas from Rainfall, Run-On, Runoff, and
Wind Dispersal Yes No N/A
Discussion/justification if SC-4 not implemented:
SC-5 Protect Trash Storage Areas from Rainfall, Run-On, Runoff, and Wind Dispersal Yes No N/A
Discussion/justification if SC-5 not implemented:
SC-6 Additional BMPs based on Potential Sources of Runoff Pollutants must answer for each source listed below and
identify additional BMPs. (See Table in Appendix E.1 of BMP Manual for guidance).
On-site storm drain inlets Yes No N/A
Interior floor drains and elevator shaft sump pumps Yes No N/A
Interior parking garages Yes No N/A
Need for future indoor & structural pest control Yes No N/A
Landscape/Outdoor Pesticide Use Yes No N/A
Pools, spas, ponds, decorative fountains, and other water features Yes No N/A
Food service Yes No N/A
Refuse areas Yes No N/A
Industrial processes Yes No N/A
Outdoor storage of equipment or materials Yes No N/A
Vehicle and Equipment Cleaning Yes No N/A
Vehicle/Equipment Repair and Maintenance Yes No N/A
Fuel Dispensing Areas Yes No N/A
Loading Docks Yes No N/A
Fire Sprinkler Test Water Yes No N/A
Miscellaneous Drain or Wash Water Yes No N/A
Plazas, sidewalks, and parking lots Yes No N/A
For “Yes” answers, identify the additional BMP per Appendix E.1. Provide justification for “No” answers.
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E-36 Page 3 of 4 Revised 09/16
Site Design BMPs
All development projects must implement site design BMPs SD-1 through SD-8 where applicable and feasible. See
Chapter 4 and Appendix E.2 thru E.6 of the BMP Design Manual (Volume 5 of City Engineering Standards) for information
to implement site design BMPs shown in this checklist.
Answer each category below pursuant to the following.
"Yes" means the project will implement the site design BMPs as described in Chapter 4 and/or Appendix E.2 thru E.6 of
the Model BMP Design Manual. Discussion / justification is not required.
"No" means the BMPs is applicable to the project but it is not feasible to implement. Discussion/justification must be
provided. Please add attachments if more space is needed.
"N/A" means the BMPs is not applicable at the project site because the project does not include the feature that is
addressed by the BMPs (e.g., the project site has no existing natural areas to conserve). Discussion/justification may be
provided.
Site Design Requirement Applied?
SD-1 Maintain Natural Drainage Pathways and Hydrologic Features Yes No N/A
Discussion/justification if SD-1 not implemented:
SD-2 Conserve Natural Areas, Soils, and Vegetation Yes No N/A
Discussion/justification if SD-2 not implemented:
SD-3 Minimize Impervious Area Yes No N/A
Discussion/justification if SD-3 not implemented:
SD-4 Minimize Soil Compaction Yes No N/A
Discussion/justification if SD-4 not implemented:
SD-5 Impervious Area Dispersion Yes No N/A
Discussion/justification if SD-5 not implemented:
I
ID ID ID
ID ID ID
ID ID ID
ID ID ID
ID ID ID
E-36 Page 4 of 4 Revised 09/16
Site Design Requirement (continued) Applied?
SD-6 Runoff Collection Yes No N/A
Discussion/justification if SD-6 not implemented:
SD-7 Landscaping with Native or Drought Tolerant Species Yes No N/A
Discussion/justification if SD-7 not implemented:
SD-8 Harvesting and Using Precipitation Yes No N/A
Discussion/justification if SD-8 not implemented:
I
ID ID ID
ID ID ID
ID ID ID
Page | 19 of 77 DRAINAGE REPORT
Madison Street & Oak Avenue
APPENDIX 4
Maps and Charts
www.HWL-PE.COM 2888 Loker Avenue East, Suite 217, Carlsbad, CA 92010 I Tel. 760.929.2288 I Email. info@HWL-PE.COM
Oak Avenue and Madison Street
1/17/2019
Basin ID
Total
Area
(ac)
Pervious
Area - Soil
Type B
(sq-ft)
Impervious
Area - Soil
Type B
(sq-ft)% Impervious % Pervious
Weighted
Runoff Coeff
C:
A.1 0.05 1963 0 100%0%0.25
A.2 0.14 5806 158 97%3%0.27
Total 0.18 AC
B
0.90
0.25
Basin ID
Total
Area
(ac)
Pervious
Area - Soil
Type B
(sq-ft)
Impervious
Area - Soil
Type B
(sq-ft)% Impervious % Pervious
Weighted
Runoff Coef
C:
A.1 0.04 91 1434 6%94%0.86
A.2 0.06 477 2333 17%83%0.79
A.3 0.01 327 266 55%45%0.54
B.1 0.02 370 670 36%64%0.67
B.2 0.05 558 1627 26%74%0.73
Total 0.18 AC
Impervious
Pervious (landscape)
Soil Type
Pre-Project Drainage
Post-Project Drainage
Runoff Coefficient Table
S:\PROJECTS\19201 OAK AND MADISON\CIVIL\REPORTS\HYDROLOGY\Appendix B - Weighted Runoff
Coefficient\Oak and Madison_drn_calcs.xlsx
Page | 20 of 77 DRAINAGE REPORT
Madison Street & Oak Avenue
--Watershed D~ivide -------------"\ '-. \~ / \ "· \ --··-~----··-···~----· ---....___ /'.-....___
'----------t----------------L-----------------t
Watershed
Divide
Effective Slope Line O.sig.n Point
(Watershed Outlet)
1----------------l ---------------->!
Area "A"= Area "8 "'
SOURCE:: ~lifomi::i DM:.ion of~~ (1011) :,,ncl Kirpioh {10t0)
Oulgn
Point
FICURE
Computation of Effective Slope for Natural Watersheds
39 ~
www.HWL-PE.C0M 2888 Loker Avenue tast, Swte 217, Carlsbad. GA 92010 I !el. 760.929.2288 J t,.,a,I. ,nto@HWL·Pt.COM
Page | 21 of 77 DRAINAGE REPORT
Madison Street & Oak Avenue
i :x ~ ;!I 8 ;=: "' 0) 0) 0) ~ ~ )> ~ ~ C: :, g, ~ ff 5· !::1 "' ~ ;;; _[ ~ ill 0 0 ~ ! "' ,,, " "' 0) 0) !::I ~. ~ 3· 0 @· I ~ r. ;!I () 0 ;;: ,-. w w IL ?; w u z ;:; ~ w (/) Q'. ::, 0 0 "' w i 1001 1-5 I H/J/., ~ ~, ~ / I ,.,I =---1' I JO (/) w ,-. ::, z 20 ~ ?; w ::;; .= ~ ..J u.. 10 o s Q'. w > 0 -0 EXAMPLE: Given: Watercourse Distance (D} = 70 Feel Slope (s) =1.3% Runoff Coefficient (C) = 0.41 OV81land FIOIV Time (T) : 9.S Minutes T= 1.8(1.1-C)'Jo •rs SOURCE: A1rpor1 D<ainage, Federal A111ation AdministraWon, 196S Rational Formula -Overland Time of Flow Nomograph 43 FIGURE 3-3
Page | 23 of 77 DRAINAGE REPORT
Madison Street & Oak Avenue
6E
FHl
5000
4000
EQUATION
Tc "' (1t~))°'385
Tc • Time or coocen1retlon (hOursJ
L Walerc;ounMJ Distilflce (mlle.)
Ci.E • Change In elevatlon along
effective slope line (See F-.gure 3-5)(1eet)
3000
woo
1000
' :iOO'
400
300
200
100
JD
20
10
5
6 E
' ' ,i~
''°" ' ' ' ' ' '
SOURCE: California Dilli&IOn c:( Highways (1941) and Klrplch (1940)
' '
L MIias Feet
'1
4000
3000
0"5 '
2000
1800
1800
1~
1200
1000
900
800
700
600
500
~
300
200
L
'
Nomogroph for Determination of
Tc
Hour5 Minutes
4
3
2
40
JO
20
18
UI
1•
' ' 12
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' 9
a
7
6
5
4
3
Tc
lime of Concentrotion (Tc) or Travel Time [Tt) for Natural Wotersheds
2'<1
www.HWL-PE.COM 2888 Loker Avenue East, Suite 217. Carlsbad, CA 92010 I Tel. 760.929.2288 I Email. info@HWL-PE.COM
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County of San Diego Hydrology Manual
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Rainfall Isopluvials
100 Year Rainfall Event- 6 Hours
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THIS MAP IS PROVIDED WITHOLIT WARRANTY OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, Copyright SanGIS. All Rights: Reserved.
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County of San Diego
Hydrology Manual
Rainfall Isopluvials
100 Year Rainfall Event-24 Hours
--------lsopluvial (inches)
Hydrologic Soil Group—San Diego County Area, California
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
12/7/2018
Page 1 of 436690203669028366903636690443669052366906036690683669020366902836690363669044366905236690603669068467757467765467773467781467789467797467805467813467821467829467837
467757 467765 467773 467781 467789 467797 467805 467813 467821 467829 467837
33° 9' 35'' N 117° 20' 44'' W33° 9' 35'' N117° 20' 41'' W33° 9' 34'' N
117° 20' 44'' W33° 9' 34'' N
117° 20' 41'' WN
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 11N WGS84
0 15 30 60 90Feet
0 5 10 20 30Meters
Map Scale: 1:379 if printed on A landscape (11" x 8.5") sheet.
Soil Map may not be valid at this scale.
USDA =
MAP LEGEND MAP INFORMATION
Area of Interest (AOI)
Area of Interest (AOI)
Soils
Soil Rating Polygons
A
A/D
B
B/D
C
C/D
D
Not rated or not available
Soil Rating Lines
A
A/D
B
B/D
C
C/D
D
Not rated or not available
Soil Rating Points
A
A/D
B
B/D
C
C/D
D
Not rated or not available
Water Features
Streams and Canals
Transportation
Rails
Interstate Highways
US Routes
Major Roads
Local Roads
Background
Aerial Photography
The soil surveys that comprise your AOI were mapped at
1:24,000.
Warning: Soil Map may not be valid at this scale.
Enlargement of maps beyond the scale of mapping can cause
misunderstanding of the detail of mapping and accuracy of soil
line placement. The maps do not show the small areas of
contrasting soils that could have been shown at a more detailed
scale.
Please rely on the bar scale on each map sheet for map
measurements.
Source of Map: Natural Resources Conservation Service
Web Soil Survey URL:
Coordinate System: Web Mercator (EPSG:3857)
Maps from the Web Soil Survey are based on the Web Mercator
projection, which preserves direction and shape but distorts
distance and area. A projection that preserves area, such as the
Albers equal-area conic projection, should be used if more
accurate calculations of distance or area are required.
This product is generated from the USDA-NRCS certified data as
of the version date(s) listed below.
Soil Survey Area: San Diego County Area, California
Survey Area Data: Version 13, Sep 12, 2018
Soil map units are labeled (as space allows) for map scales
1:50,000 or larger.
Date(s) aerial images were photographed: Nov 3, 2014—Nov
22, 2014
The orthophoto or other base map on which the soil lines were
compiled and digitized probably differs from the background
imagery displayed on these maps. As a result, some minor
shifting of map unit boundaries may be evident.
Hydrologic Soil Group—San Diego County Area, California
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
12/7/2018
Page 2 of 4USDA =
□
D
D
D
D
D
D
D
D
,,..,,,.
,,..,,,.
□
■
■
□
□
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•
Hydrologic Soil Group
Map unit symbol Map unit name Rating Acres in AOI Percent of AOI
MlC Marina loamy coarse
sand, 2 to 9 percent
slopes
B 0.3 100.0%
Totals for Area of Interest 0.3 100.0%
Description
Hydrologic soil groups are based on estimates of runoff potential. Soils are
assigned to one of four groups according to the rate of water infiltration when the
soils are not protected by vegetation, are thoroughly wet, and receive
precipitation from long-duration storms.
The soils in the United States are assigned to four groups (A, B, C, and D) and
three dual classes (A/D, B/D, and C/D). The groups are defined as follows:
Group A. Soils having a high infiltration rate (low runoff potential) when
thoroughly wet. These consist mainly of deep, well drained to excessively
drained sands or gravelly sands. These soils have a high rate of water
transmission.
Group B. Soils having a moderate infiltration rate when thoroughly wet. These
consist chiefly of moderately deep or deep, moderately well drained or well
drained soils that have moderately fine texture to moderately coarse texture.
These soils have a moderate rate of water transmission.
Group C. Soils having a slow infiltration rate when thoroughly wet. These consist
chiefly of soils having a layer that impedes the downward movement of water or
soils of moderately fine texture or fine texture. These soils have a slow rate of
water transmission.
Group D. Soils having a very slow infiltration rate (high runoff potential) when
thoroughly wet. These consist chiefly of clays that have a high shrink-swell
potential, soils that have a high water table, soils that have a claypan or clay
layer at or near the surface, and soils that are shallow over nearly impervious
material. These soils have a very slow rate of water transmission.
If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is
for drained areas and the second is for undrained areas. Only the soils that in
their natural condition are in group D are assigned to dual classes.
Rating Options
Aggregation Method: Dominant Condition
Hydrologic Soil Group—San Diego County Area, California
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
12/7/2018
Page 3 of 4USDA =
Aggregation is the process by which a set of component attribute values is
reduced to a single value that represents the map unit as a whole.
A map unit is typically composed of one or more "components". A component is
either some type of soil or some nonsoil entity, e.g., rock outcrop. For the
attribute being aggregated, the first step of the aggregation process is to derive
one attribute value for each of a map unit's components. From this set of
component attributes, the next step of the aggregation process derives a single
value that represents the map unit as a whole. Once a single value for each map
unit is derived, a thematic map for soil map units can be rendered. Aggregation
must be done because, on any soil map, map units are delineated but
components are not.
For each of a map unit's components, a corresponding percent composition is
recorded. A percent composition of 60 indicates that the corresponding
component typically makes up approximately 60% of the map unit. Percent
composition is a critical factor in some, but not all, aggregation methods.
The aggregation method "Dominant Condition" first groups like attribute values
for the components in a map unit. For each group, percent composition is set to
the sum of the percent composition of all components participating in that group.
These groups now represent "conditions" rather than components. The attribute
value associated with the group with the highest cumulative percent composition
is returned. If more than one group shares the highest cumulative percent
composition, the corresponding "tie-break" rule determines which value should
be returned. The "tie-break" rule indicates whether the lower or higher group
value should be returned in the case of a percent composition tie. The result
returned by this aggregation method represents the dominant condition
throughout the map unit only when no tie has occurred.
Component Percent Cutoff: None Specified
Components whose percent composition is below the cutoff value will not be
considered. If no cutoff value is specified, all components in the database will be
considered. The data for some contrasting soils of minor extent may not be in the
database, and therefore are not considered.
Tie-break Rule: Higher
The tie-break rule indicates which value should be selected from a set of multiple
candidate values, or which value should be selected in the event of a percent
composition tie.
Hydrologic Soil Group—San Diego County Area, California
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
12/7/2018
Page 4 of 4~