HomeMy WebLinkAboutMS 08-03; NOLAN DEVELOPMENT; HYDROLOGY, HYDRAULIC AND STORMWATER STUDY; 2015-01-28I
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1 HYDROLOGY, HYDRAULIC AND
STORMWATER STUDY
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NOLAN DEVELOPMENT
7331 LAS BRISAS COURT, CARLSBAD
APN 223-211-18
Prepared for:
Frank and Joann Nolan Trust
7331 Las Brisas Court
Carlsbad, CA 92009
Prepared by:
a
bhA, Inc.
land planning, civil engineering, surveying
5115 Avenida Encinas, Suite L
carlsbad, CA 92008-4387
(760) 931-870 o
No. 29271 December 29, 2014
Revised: January 28, 20
1?-7
MAR 10 2"'15 W.O. 739-0993-40 tJk%'U LJV%;
TABLE OF CONTENTS
I. Discussion: Vicinity Map......................................................3
Purpose and Scope..............................................4
Project Description..............................................4
StudyMethod.....................................................4
Conclusions........................................................6
Declaration of Responsible Charge..........................7
II. Exhibits: Existing Hydrology Map &
Proposed Hydrology Map ......................................................8
III. Calculations: A. Existing Condition Hydrology Calculations........................9
Proposed Condition Hydrology Calculations....................... 12
Hydraulic Calculations...............................................16
IV. References........................................................................................19
Nolan Development- Hydrology Study bl-iA, Inc.
i. DISCUSSION
VICINITY MAP
NO SCALE
Nolan Development- Hydrology Study H-IA, inc.
PURPOSE AND SCOPE:
The purpose of this report is to publish the results of hydrology and hydraulic computer analysis
for the Tentative Parcel Map, MS-08-03, City of Carlsbad, known for the purposes of this report as
Nolan Development. The scope is to study the proposed hydrology and hydraulics, and make
recommendations to intercept, detain and convey 0100.
PROJECT DESCRIPTION:
The project proposes to subdivide the existing property into two parcels. The site is located
between the westerly end of Las Brisas Court and the easterly right of way of Piragua Street.
Currently the site has an existing single family residential structure located near the easterly
property line, with access from Las Brisas Court. The existing pad for this residence overlooks the
remaining lower portion of the property to the west. This lower portion of the property is partly
rough graded with a dirt road from Piragua Street used for access by San Diego Gas & Electric
Company. The project is surrounded by existing single family residences.
Runoff from the existing site is intercepted by a storm drain system north of the property. The
upper lot drains into a street curb inlet in Las Brisas Court. A portion of the lower half of the
property drains into a catch basin near the northwesterly corner. The remainder of the lower half
drains onto Piragua Street, towards a street curb inlet near the northwest corner of the property.
STUDY METHOD:
The method of analysis was based on the Rational Method according to the San Diego County
Hydrology Manual, 2003 edition. The hydrology and hydraulic analysis were performed using
Hydrosoft by Advanced Engineering Software.
I Drainage basin areas were determined from flown topography and proposed finish grades as
shown on the Tentative Parcel Map. Using the Rational Method, the on-site runoff coefficients
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were determined as:
User Specified Storm Event (Year) = 100
I P6 for 100-year storm= 2.8", see Isopluvial map in References.
I Soil Classification of "D" will be assumed for the drainage basins for the hydrology calculation,
see USDA Web Soil Survey in References. Composite Runoff Coefficients were calculated for
drainage areas with both pervious and pervious surfaces, per the following Table 1.0.
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Nolan Development- Hydrology Study bkA, Inc.
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Table 1.0—Composite C-value Calculations
Proposed Hydrology
Up
Node
Down
Node
Total
Acreage
C1 A1
(acres)
C2 A2
(acres)
Ccomp
14 13 0.213 0.35 0.145 0.87 0.068 0.52
13.1 13 0.090 0.35 0.043 0.87 0.047 0.62
11 10 0.206 0.35 0.181 0.87 0.025 0.41
Note: C-values taken from Table 3-1 of San Diego County Hydrology Manual,
consistent with on-site existing soil types from the USDA Web Soil Survey. See
Appendix.
Table 1.1—Summary of Results
100 Year Storm Frequency
Existing Condition Proposed Condition
Node Acres Q (cfs) Tc (mm) Node
10 _40C.
cres 0 (cfs) Tc (mm)
1 0.7 1.17 9.6 0.7 1.57 9.13
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Nolan Development- Hydrology Study bhA, Inc.
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I CONCLUSION:
This report has shown that the proposed Nolan Development will not generate substantial
I stormwater runoff to adversely affect downstream properties and drainage infrastructure. It is our
professional opinion that the recommendations provided in this report, and the drainage system as
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proposed effectively intercept, contain, detain and convey the expected storm water runoff
generated by this property.
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Nolan Development- Hydrology Study bkA, Inc.
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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 current standards.
I understand that the check of 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.
z-cK
Ronald L. HolTowaP R.C.E. 29271 Date
Nolan Development- Hydrology Study bhA, inc.
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BAD I!1OJ-,4W $JV#LW !U&!i. WE VNWW1
40 60
/
20 10 0 20
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SCALE 1" 20'
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381,5 j/
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--- --.-- -_---.
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/
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LEGEND
SURFACE NODE
SURFACE RUNOFF (Cr5)
BASIN AREA 'AcRES)
436.1 \.
N
FL 0 WLINE
X
x
5115 AVENIDA ENCINAS
SUITE "L"
CARLSBAD, CA. 92008-4387
(760) 931-8700
N /
4' -\
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')F 'I I
If
96 , /
4..4L
/ 39'7,/
/ IC'
VICINITY MAP
NO SCALE
!WOJ 'WJ4D !IDRtOLOiT' .9
V'IOJ4IJ DJfl!OJ !HI '0)- vJ3.vD 7777'
20 10 0 20 40 60
SCALE: 1" = 20'
r '
i1:j ,,.,_
:i>• "f" ...j.
3 E 10
"I
'Ti
!" 1;
I ...
go
\ I/;
/ \jk
I / I
COMPOSITE C-VALUE CALCULATIONS:
-,......
/
-.
/
Proposed Hydrology
Up Node Down
Node
Total
Acreage
c1 A1 (acres) C2 A2
(acres)
Ccomp
14 13 0.213 0.35 0.145 0.87 0.068 0.52
13.1 13 0.090 0.35 0.043 0.87 1 0.047 0.62
11 10 0.206 0.35 0.181 0.87 1 0.025 0.41
Note: C-values taken from Table 3-1 of San Diego County Hydrology Manual,
consistent with on-site existing soil types from the USDA Web Soil Survey. See
DEEP ROOTED, DENSE, DROUGHT
TOLERANT PLANTiNG SUITABLE
FOR WELL DRAINED SOIL CORE 1" HOLE AT
OPPOSITE SIDES OF IN
CATCH BASIN FOR DRAW
DOWN TIME. BOTTOM OF 1"
'ffl=°t
HOLE TO BE 0.17' ABOVE
BOTTOM OF BASIN.
FS=393. 0
18"x18" BROOKS BOX
77H PARKWAY GRATE
OUTFLOW TO D-27
UNDER WALK DRAIN ON
PIRA GUA ST
OUTLET PIPE IE=391.3 (2) 3" Pvc
DETENTION BASIN OUTLET DETAIL
NOT TO SCALE
LEGEND
SURFACE NODE
SURFACE RUNOFF (cFs) 9)
BASIN AREA (ACRES) cTö
FLOWLINE
0-27 UNDERDRAIN
in. planning, chAl engheeeng, SLffVyint
5115 AVENIDA ENCINAS
SUITE "L"
CARLSBAD, CA. 92008-4387
(760) 931-8700
VICINITY MAP
NO SCALE
K:\Land Projects 3\739-0993-400\dWg\hYd ro-swppp\0993-HYDRO- PRO P.dW9i 2/2/2015 10:54:50 AM
---...
•TT •• ........... .,
...-
II. EXHIBITS
EXISTING HYDROLOGY MAP
PROPOSED HYDROLOGY MAP
Nolan Development- Hydrology Study bkA, inc.
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III. CALCULATIONS
A. EXISTING CONDITION HYDROLOGY CALCULATIONS
****************************************************************************
RATIONAL METHOD HYDROLOGY COMPUTER PROGRAM PACKAGE
Reference: SAM DIEGO COUNTY FLOOD CONTROL DISTRICT
2003,1985,1981 HYDROLOGY MANUAL
(c) Copyright 1982-2012 Advanced Engineering Software (aes)
Ver. 19.0 Release Date: 06/01/2012 License ID 1459
Analysis prepared by:
BHA Inc
5115 Avenida Encinas, Suite L
Carlsbad CA 92008
* * * * * * * * * * * * * * * * * * * * * * * * * * DESCRIPTION OF STUDY * * * * * * * * * * * * * * * * * * * * * * * * * *
* 100 Year Hydrology Analysis, Existing Condition bi *
* Nolan Development *
* *
**************************************************************************
I FILE NAME: 0993E100.DAT
TIME/DATE OF STUDY: 13:39 04/01/2013
I USER SPECIFIED HYDROLOGY AND HYDRAULIC MODEL INFORMATION:
2003 SAN DIEGO MANUAL CRITERIA
I USER SPECIFIED STORM EVENT(YEAR) = 100.00
6-HOUR DURATION PRECIPITATION (INCHES) = 2.800
SPECIFIED MINIMUM PIPE SIZE(INCH) = 3.00
I SPECIFIED PERCENT OF GRADIENTS(DECIMAL) TO USE FOR FRICTION SLOPE = 0.95
SAN DIEGO HYDROLOGY MANUAL 'C-VALUES USED FOR RATIONAL METHOD
NOTE: USE MODIFIED RATIONAL METHOD PROCEDURES FOR CONFLUENCE ANALYSIS
I *USER_DEFINED STREET-SECTIONS FOR COUPLED PIPEFLOW AND STREETFLOW MODEL*
HALF- CROWN TO STREET-CROSSFALL: CURB GUTTER-GEOMETRIES: MANNING
WIDTH CROSSFALL IN- / OUT-/PARK- HEIGHT WIDTH LIP HIKE FACTOR
NO. (FT) (FT) SIDE / SIDE! WAY (FT) (FT) (FT) (FT) (n)
I 1 30.0 20.0 0.018/0.018/0.020 0.67 2.00 0.0313 0.167 0.0150
I GLOBAL STREET FLOW-DEPTH CONSTRAINTS:
1. Relative Flow-Depth = 0.00 FEET
as (Maximum Allowable Street Flow Depth) - (Top-of-Curb)
I
2. (Depth)*(Velocity) Constraint = 6.0 (FT*FT!S) *SIZE PIPE WITH A FLOW CAPACITY GREATER THAN
OR EQUAL TO THE UPSTREAM TRIBUTARY PIPE.*
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Nolan Development- Hydrology Study H-IA, inc.
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****************************************************************************
FLOW PROCESS FROM NODE 4.00 TO NODE 3.00 Is CODE = 21
----------------------------------------------------------------------------
>>>>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<<<<<
*USER SPECIFIED(SUBAREA):
USER-SPECIFIED RUNOFF COEFFICIENT = .3500
S.C.S. CURVE NUMBER (AMC II) = 0
INITIAL SUBAREA FLOW-LENGTH(FEET) = 100.00
UPSTREAM ELEVATION(FEET) = 432.00
DOWNSTREAM ELEVATION(FEET) = 416.00
ELEVATION DIFFERENCE(FEET) = 16.00
SUBAREA OVERLAND TIME OF FLOW(MIN.) = 6.267
WARNING: THE MAXIMUM OVERLAND FLOW SLOPE, 10.%, IS USED IN Tc CALCULATION!
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 6.377
SUBAREA RUNOFF(CFS) = 0.08
TOTAL AREA(ACRES) = 0.04 TOTAL RUNOFF(CFS) = 0.08
****************************************************************************
FLOW PROCESS FROM NODE 4.00 TO NODE 3.00 IS CODE = 7
----------------------------------------------------------------------------
>>>>>USER SPECIFIED HYDROLOGY INFORMATION AT NODE<<<<<
USER-SPECIFIED VALUES ARE AS FOLLOWS:
TC(MIN) = 6.27 RAIN INTENSITY(INCH/HOUR) = 6.38
TOTAL AREA(ACRES) = 0.04 TOTAL RUNOFF(CFS) = 0.10
****************************************************************************
FLOW PROCESS FROM NODE 3.00 TO NODE 2.00 IS CODE = 51
----------------------------------------------------------------------------
>>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<<
>>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT)<<<<<
ELEVATION DATA: UPSTREAM(FEET) 416.00 DOWNSTREAM(FEET) = 395.00
CHANNEL LENGTH THRU SUBAREA(FEET) = 140.00 CHANNEL SLOPE = 0.1500
CHANNEL BASE(FEET) = 15.00 "Z" FACTOR = 8.000
MANNING 'S FACTOR = 0.040 MAXIMUM DEPTH(FEET) = 1.00
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.046
*USER SPECIFIED(SUBAREA):
USER-SPECIFIED RUNOFF COEFFICIENT = .3500
S.C.S. CURVE NUMBER (AMC II) = 0
TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 0.16
TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 0.85
AVERAGE FLOW DEPTH(FEET) = 0.01 TRAVEL TIME(MIN.) = 2.74
Tc(MIN.) = 9.01
SUBAREA AREA(ACRES) = 0.06 SUBAREA RUNOFF(CFS) = 0.11
AREA-AVERAGE RUNOFF COEFFICIENT = 0.381
TOTAL AREA(ACRES) = 0.1 PEAK FLOW RATE(CFS) = 0.19
END OF SUBAREA CHANNEL FLOW HYDRAULICS:
DEPTH(FEET) = 0.01 FLOW VELOCITY(FEET/SEC.) = 1.04
LONGEST FLOWPATH FROM NODE 4.00 TO NODE 2.00 = 240.00 FEET.
****************************************************************************
FLOW PROCESS FROM NODE 2.00 TO NODE 1.00 IS CODE = 61
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Nolan Development- Hydrology Study bkA, Inc.
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----------------------------------------------------------------------------
>>>>>COMPUTE STREET FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>(STANDARD CURB SECTION USED)<<<<<
UPSTREAM ELEVATION(FEET) = 395.00 DOWNSTREAM ELEVATION(FEET) = 382.60
STREET LENGTH(FEET) = 194.00 CURB HEIGHT(INCHES) = 6.0
STREET HALFWIDTH(FEET) = 16.00
DISTANCE FROM CROWN TO CROSSFALL GRADEBREAK(FEET) = 8.00
INSIDE STREET CROSSFALL(DECIMAL) = 0.020
OUTSIDE STREET CROSSFALL(DECIMAL) = 0.020
SPECIFIED NUMBER OF HALFSTREETS CARRYING RUNOFF = 1
Mannings FRICTION FACTOR for Streetf low Section(curb-to-curb) =
**TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 0.68
STREETFLOW MODEL RESULTS USING ESTIMATED FLOW:
STREET FLOW DEPTH(FEET) = 0.16
HALFSTREET FLOOD WIDTH(FEET) = 1.50
AVERAGE FLOW VELOCITY(FEET/SEC.) = 5.50
PRODUCT OF DEPTH&VELOCITY(FT*FT/SEC.) = 0.86
STREET FLOW TRAVEL TIME(MIN.) = 0.59 Tc(MIN.) = 9.60
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.845
*USER SPECIFIED(SUBAREA):
USER-SPECIFIED RUNOFF COEFFICIENT = .3500
S.C.S. CURVE NUMBER (AMC II) = 0
0.0130
AREA-AVERAGE RUNOFF COEFFICIENT = 0.355
SUBAREA AREA(ACRES) = 0.58 SUBAREA RtJNOFF(CFS) = 0.98
TOTAL AREA(ACRES) = 0.7 PEAK FLOW RATE(CFS) = 1.17
END OF SUBAREA STREET FLOW HYDRAULICS:
DEPTH(FEET) = 0.20 HALFSTREET FLOOD WIDTH(FEET) = 3.62
FLOW VELOCITY(FEET/SEC.) = 4.68 DEPTH*VELOCITY(FT*FT/SEC.) = 0.93
LONGEST FLOWPATH FROM NODE 4.00 TO NODE 1.00 = 434.00 FEET.
END OF STUDY SUMMARY:
TOTAL AREA(ACRES) = 0.7 TC(MIN.) = 9.60
PEAK FLOW RATE(CFS) 1.17
END OF RATIONAL METHOD ANALYSIS
Nolan Development- Hydrology Study blIA, Inc.
B. PROPOSED CONDITION HYDROLOGY CALCULATIONS
****************************************************************************
RATIONAL METHOD HYDROLOGY COMPUTER PROGRAM PACKAGE
I
Reference: SAN DIEGO COUNTY FLOOD CONTROL DISTRICT
2003,1985,1981 HYDROLOGY MANUAL
(c) Copyright 1982-2012 Advanced Engineering Software (aes)
I
Ver. 19.0 Release Date: 06/01/2012 License ID 1459
Analysis prepared by:
I BHA Inc
5115 Avenida Encinas, Suite L
Carlsbad CA 92008
l ************************** DESCRIPTION OF STUDY
* 100 Year Hydrology Analysis, Developed Condition bl *
* Nolan Development *
I * *
**************************************************************************
I
FILE NAME: 0993P100.DAT
TIME/DATE OF STUDY: 13:29 04/01/2013
----------------------------------------------------------------------------
USER SPECIFIED HYDROLOGY AND HYDRAULIC MODEL INFORMATION:
I 2003 SAN DIEGO MANUAL CRITERIA
I
USER SPECIFIED STORM EVENT(YEAR) = 100.00
6-HOUR DURATION PRECIPITATION (INCHES) = 2.800
SPECIFIED MINIMUM PIPE SIZE(INCH) = 3.00
SPECIFIED PERCENT OF GRADIENTS(DECIMAL) TO USE FOR FRICTION SLOPE = 0.95
I SAN DIEGO HYDROLOGY MANUAL 'C-VALUES USED FOR RATIONAL METHOD
NOTE: USE MODIFIED RATIONAL METHOD PROCEDURES FOR CONFLUENCE ANALYSIS
*USER_DEFINED STREET-SECTIONS FOR COUPLED PIPEFLOW AND STREETFLOW MODEL*
I HALF- CROWN TO STREET-CROSSFALL: CURB GUTTER-GEOMETRIES: MANNING
WIDTH CROSSFALL IN- / OUT-/PARK- HEIGHT WIDTH LIP HIKE FACTOR
NO. (FT) (FT) SIDE / SIDE/ WAY (FT) (FT) (FT) (FT) (n)
I 1 30.0 20.0 0.018/0.018/0.020 0.67 2.00 0.0313 0.167 0.0150
GLOBAL STREET FLOW-DEPTH CONSTRAINTS:
I l. Relative Flow-Depth = 0.00 FEET
as (Maximum Allowable Street Flow Depth) - (Top-of-Curb)
2. (Depth)*(Velocity) Constraint = 6.0 (FT*FT/S)
I
*SIZE PIPE WITH A FLOW CAPACITY GREATER THAN
OR EQUAL TO THE UPSTREAM TRIBUTARY PIPE.*
****************************************************************************
FLOW PROCESS FROM NODE 15.00 TO NODE 14.00 IS CODE = 21
>>>>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<<<<<
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I Nolan Development- Hydrology Study bliA, Inc.
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*USER SPECIFIED(SUBAREA):
USER-SPECIFIED RUNOFF COEFFICIENT = .3500
S.C.S. CURVE NUMBER (AMC II) = 0
INITIAL SUBAREA FLOW-LENGTH(FEET) = 100.00
UPSTREAM ELEVATION(FEET) = 432.00
DOWNSTREAM ELEVATION(FEET) = 416.00
ELEVATION DIFFERENCE(FEET) = 16.00
SUBAREA OVERLAND TIME OF FLOW(MIN.) = 6.267
WARNING: THE MAXIMUM OVERLAND FLOW SLOPE, 10.%, IS USED IN Tc CALCULATION!
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 6.377
SUBAREA RUNOFF(CFS) = 0.08
TOTAL AREA(ACRES) = 0.04 TOTAL RUNOFF(CFS) = 0.08
****************************************************************************
FLOW PROCESS FROM NODE 15.00 TO NODE 14.00 IS CODE = 7
----------------------------------------------------------------------------
>>>>>USER SPECIFIED HYDROLOGY INFORMATION AT NODE<'z<<<
USER-SPECIFIED VALUES ARE AS FOLLOWS:
TC(MIN) = 6.27 RAIN INTENSITY(INCH/HOUR) = 6.38
TOTAL AREA(ACRES) = 0.04 TOTAL RUNOFF(CFS) = 0.10
****************************************************************************
FLOW PROCESS FROM NODE 14.00 TO NODE 13.00 IS CODE = 51
----------------------------------------------------------------------------
>>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<<
>>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT)<<<<<
ELEVATION DATA: UPSTREAM(FEET) = 416.00 DOWNSTREAM(FEET) = 395.00
CHANNEL LENGTH THRU SUBAREA(FEET) 152.00 CHANNEL SLOPE = 0.1382
CHANNEL BASE(FEET) = 16.00 Z FACTOR = 2.000
MANNING 'S FACTOR = 0.040 MAXIMUM DEPTH(FEET) = 1.00
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.307
*USER SPECIFIED(SUBAREA):
USER-SPECIFIED RUNOFF COEFFICIENT = .5200
S.C.S. CURVE NUMBER (AMC II) = 0
TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 0.39
TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 1.23
AVERAGE FLOW DEPTH(FEET) = 0.02 TRAVEL TIME(MIN.) = 2.06
Tc(MIN.) = 8.33
SUBAREA AREA(ACRES) = 0.21 SUBAREA RUNOFF(CFS) = 0.59
AREA-AVERAGE RUNOFF COEFFICIENT = 0.508
TOTAL AREA(ACRES) = 0.2 PEAK FLOW RATE(CFS) = 0.67
END OF SUBAREA CHANNEL FLOW HYDRAULICS:
DEPTH(FEET) = 0.03 FLOW VELOCITY(FEET/SEC.) = 1.25
LONGEST FLOWPATH FROM NODE 15.00 TO NODE 13.00 = 252.00 FEET.
****************************************************************************
FLOW PROCESS FROM NODE 13.10 TO NODE 13.00 IS CODE = 81 ----------------------------------------------------------------------------
>>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.307
Nolan Development- Hydrology Study bi-IA, Inc.
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I *USER SPECIFIED(SUBAREA):
USER-SPECIFIED RUNOFF COEFFICIENT = .6200
S.C.S. CURVE NUMBER (AMC II) = 0
I AREA-AVERAGE RUNOFF COEFFICIENT = 0.5376
SUBAREA AREA(ACRES) = 0.09 SUBAREA RUNOFF(CFS) = 0.30
TOTAL AREA(ACRES) = 0.3 TOTAL RUNOFF(CFS) = 0.97
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TC(MIN.) = 8.33
****************************************************************************
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FLOW PROCESS FROM NODE 13.00 TO NODE 12.00 IS CODE = 51
>>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<<
>>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT)<<z<<<
I ELEVATION DATA: UPSTREAM(FEET) = 395.00 DOWNSTREAM(FEET) = 393.00
CHANNEL LENGTH THRU SUBAREA(FEET) = 100.00 CHANNEL SLOPE = 0.0200
CHANNEL BASE(FEET) = 0.00 "Z" FACTOR = 2.000
I MANNING'S FACTOR = 0.015 MAXIMUM DEPTH(FEET) = 1.00
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.148
*USER SPECIFIED(SUBAREA):
I USER-SPECIFIED RUNOFF COEFFICIENT = .3500
S.C.S. CURVE NUMBER (AMC II) = 0
TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 1.00
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TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 4.14
AVERAGE FLOW DEPTH(FEET) = 0.35 TRAVEL TIME(MIN.) = 0.40
Tc(MIN.) = 8.73
SUBAREA AREA(ACRES) = 0.04 SUBAREA RUNOFF(CFS) = 0.07
I AREA-AVERAGE RUNOFF COEFFICIENT = 0.518
TOTAL AREA(ACRES) = 0.4 PEAK FLOW RATE(CFS) = 1.01
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END OF SUBAREA CHANNEL FLOW HYDRAULICS:
DEPTH(FEET) = 0.35 FLOW VELOCITY(FEET/SEC.) = 4.03
LONGEST FLOWPATH FROM NODE 15.00 TO NODE 12.00 = 352.00 FEET.
****************************************************************************
FLOW PROCESS FROM NODE 12.10 TO NODE 12.00 IS CODE = 81 ----------------------------------------------------------------------------
>>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.148
*USER SPECIFIED(SUBAREA):
USER-SPECIFIED RUNOFF COEFFICIENT = .3500
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.4839
SUBAREA AR
EA(ACRES) = 0.10 SUBAREA RUNOFF(CFS) = 0.17
TOTAL AREA(ACRES) = 0.5 TOTAL RUNOFF(CFS) = 1.18
TC(MIN.) = 8.73
I ****************************************************************************
FLOW PROCESS FROM NODE 12.00 TO NODE 11.00 IS CODE = 41
----------------------------------------------------------------------------
I >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<<
ELEVATION DATA: UPSTREAM(FEET) = 391.30 DOWNSTREAM(FEET) = 388.00
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I FLOW LENGTH(FEET) = 30.00 MANNING'S N = 0.011
ASSUME FULL-FLOWING PIPELINE
PIPE-FLOW VELOCITY(FEET/SEC.) = 12.05
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PIPE FLOW VELOCITY = (TOTAL FLOW)/(PIPE CROSS SECTION AREA)
GIVEN PIPE DIAMETER(INCH) = 3.00 NUMBER OF PIPES = 2
PIPE-FLOW(CFS) = 1.18
PIPE TRAVEL TIME(MIN.) = 0.04 Tc(MIN.) = 8.78
I LONGEST FLOWPATH FROM NODE 15.00 TO NODE 11.00 = 382.00 FEET.
I FLOW PROCESS FROM NODE 11.00 TO NODE 10.00 IS CODE = 61
>>>>>COMPUTE STREET FLOW TRAVEL TIME THRU SUBAREA<<<<<
I
>>>>>(STANDARD CURB SECTION USED)<<<<<
UPSTREAM ELEVATION(FEET) = 388.00 DOWNSTREAM ELEVATION(FEET) = 382.60
STREET LENGTH(FEET) = 95.00 CURB HEIGHT(INCHES) = 6.0
I STREET HALFWIDTH(FEET) = 16.00
DISTANCE FROM CROWN TO CROSSFALL GRADEBREAK(FEET) = 8.00
I
INSIDE STREET CROSSFALL(DECIMAL) = 0.020
OUTSIDE STREET CROSSFALL(DECIMAL) = 0.020
SPECIFIED NUMBER OF HALFSTREETS CARRYING RUNOFF = 1
I Manning's FRICTION FACTOR for Streetf low Section(curb-to-curb) = 0.0130
**TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 1.39
I STREETFLOW MODEL RESULTS USING ESTIMATED FLOW:
STREET FLOW DEPTH(FEET) = 0.21
HALFSTREET FLOOD WIDTH(FEET) = 4.36
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AVERAGE FLOW VELOCITY(FEET/SEC.) = 4.52
PRODUCT OF DEPTH&VELOCITY(FT*FT/SEC.) = 0.97
STREET FLOW TRAVEL TIME(MIN.) = 0.35 Tc(MIN.) = 9.13
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.004
I *USER SPECIFIED(SUBAREA):
USER-SPECIFIED RUNOFF COEFFICIENT = .4100
S.C.S. CURVE NUMBER (AMC II) = 0
I
AREA-AVERAGE RUNOFF COEFFICIENT = 0.462
SUBAREA AREA(ACRES) = 0.21 SUBAREA RUNOFF(CFS) = 0.42
TOTAL AREA(ACRES) = 0.7 PEAK FLOW RATE(CFS) = 1.57
END OF SUBAREA STREET FLOW HYDRAULICS:
DEPTH(FEET) = 0.22 HALFSTREET FLOOD WIDTH(FEET) = 4.76
FLOW VELOCITY(FEET/SEC.) = 4.57 DEPTH*VELOCITY(FT*FT/SEC.) 1.01
LONGEST FLOWPATH FROM NODE 15.00 TO NODE 10.00 = 477.00 FEET.
END OF STUDY SUMMARY:
TOTAL AREA(ACRES) = 0.7 TC(MIN.) = 9.13
PEAK
FLOW RATE(CFS) = 1.57
END OF RATIONAL METHOD ANALYSIS
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Nolan Development- Hydrology Study bliA, Inc.
C. HYDRAULIC CALCULATIONS
HYDRAULIC ELEMENTS - I PROGRAM PACKAGE
(C) Copyright 1982-2012 Advanced Engineering Software (aes)
Ver. 19.0 Release Date: 06/01/2012 License ID 1459
Analysis prepared by:
BHA Inc
5115 Avenida Encinas, Suite L
Carlsbad CA 92008
---------------------------------------------------------------------------- TIME/DATE OF STUDY: 13:46 04/01/2013
I
Problem Descriptions:
Outlet Pipe Sizing Calculations Based on 100-Year Storm Event
Nolan Development
****************************************************************************
>> > >PIPEFLOW HYDRAULIC INPUT INFORMATION< < < <
----------------------------------------------------------------------------
PIPE SLOPE(FEET/FEET) = 0.1100
PIPEFLOW(CFS) = 1.18
MANNINGS FRICTION FACTOR = 0.011000
> > > > >SOFFIT-FLOW PIPE DIAMETER(FEET) = 0.396
-Will use (2) 3"-dia HDPE pipes from outlet of basin, run to Standard Curb Outlet per D-27 to
Piragua St.
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Nolan Development- Hydrology Study bl-iA, Inc.
J__1_6 __L_
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Table 2.A- Capacity of 18"x18" Brooks Box, Basin Outlet
Using Sharp Crested Weir Formula equation (5-10) Q=CLH'5 where Coefficient C is 3.3 (Brater and King)
I
Weir Length Basin Elev Coefficient H (if) Q (cfs) (It)
0.9 3.3 6 0.067 0.34
1 3.3 6 0.167 1.35 > 1.18 cfs QIN ''
11
B 1"
TABLE 2.- Capacity of -dia Orifices Q = x Cg x D2 .12
i
Using General Orifice Flow equation:
where (H-Hd) equals available Head, g = 32.2 ft/s2, D is the orifice diameter, and Cg is the orifice discharge
I coefficient.
Elev. (It)
Basin
Depth
. . Orifice Size
Dia.(ft)
Cg
(considering
thick walls)
Head (if) Qdischarge
(cfs) X 2 total orifices
393.17 0.17 0.083333333 0.75 0.0667 0.008 0.017
393.2 0.2 0.083333333 0.75 0.1667 0.013 0.027
393.3 0.3 0.083333333 0.75 0.2667 0.017 0.034
393.4 0.4 0.083333333 0.75 0.3667 0.020 0.040
393.5 0.5 0.083333333 0.75 0.4667 0.022 0.045
393.6 0.6 0.083333333 0.75 0.5667 0.025 0.049
393.7 0.7 0.083333333 0.75 0.6667 0.027 0.054
393.8 0.8 0.083333333 0.75 0.7667 0.029 0.057
393.9 0.9 0.083333333 0.75 0.8667 0.031 0.061
394 1 0.083333333 0.75 0.9667 0.032 0.065
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Table 2.C- Basin Depth vs. Storage and Discharge Information
I Basin Bottom Basin Area (sf) = 241
Volume CF Depth Volume acre-ft Outflow X 2 Outlet Pipes
90.38 0.00 0.0021 0.000 0.000
115.08 0.10 0.0026 0.000 0.000
133.08 0.17 0.0031 0.017 0.034
140.98 0.20 0.0032 0.027 0.054
168.08 0.30 0.0039 0.034 0.068
196.38 0.40 0.0045 0.040 0.079
225.88 0.50 0.0052 0.045 0.090
256.58 0.60 0.0059 0.049 0.099
288.48 0.70 0.0066 0.054 0.107
321.58 0.80 0.0074 0.057 0.115
355.88 0.90 0.0082 0.402 0.804
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I Nolan Development- Hydrology Study bhA, Inc.
17
391.38 1.00 0.0090 1.412 2.823 > 1.18 cfs QIN "
Drawdown calculator:
Flow through orifice plate governs drain-down flow:
355 Basin Volume @ 10" Depth (cf)
0.804 Q of (2) 3" PVC outlet pipes at 10" Basin Depth (cfs)
0.1 1 Drawdown Time (hrs) < 72 v'
DEEP ROOTED, DENSE, DROUGHT
TOLERANT PLANT/NC SUITABLE
FOR WELL DRAINED SOIL - CORE A 1" HOLE AT
OPPOSITE SIDES OF IN
CA TCH BASIN FOR DRAW 18"x18" BROOKS BOX
DOWN TIME. BOTTOM OF 1" PARKWAY CRATE
HOLE TO BE 0.17' ABOVE
/TH
BOTTOM OF BASIN.
Uio"
OUTFLOW TO D-27
UNDER WALK DRAIN ON
PIRACUA ST
_jij N_OU TLET PIPE
(2) 3" PVC
DE TENTION BA SIN 0 UTLETDE TAIL
NOT TO SCALE
Nolan Development- Hydrology Study bliA, Inc.
18
IV. REFERENCES
I
Nolan Development- Hydrology Study bElA, Inc.
19
- I
= I r-n nHW ET- L
.
County of San Diego
44
-One _, Hydrology Manual
I ,Lfl I I 33311
LL du'n pli
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-__- Rainfall Isopluvials
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Yew kaluf.ffEveet 6H,w, J J R,
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'GPS 33'5'20.2"
117 1467
11 F 1 - -1__J_..__f.
________ - - P 2.8 6 -
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Lr'YNI '1
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County of San Diego
Hydrology Manual
C
Rainfall Isopluvials
III Yew RaWaN Evi.t -24 H.en
- _)
GPS: 33°5'20.2"
-117° 146.7"
P6 = 2.8"
P24 = 5.1"
P6 /P24 _55%
II
33 521' 33 521"
33 19'
Hydrologic Soil Group—ear Deg. County Area, California
Map Scale 1383 if printed on A size 85" x 11) 'set
N •kt&rs
A 0 36 7 14 21
Feet
0 10 20 40 ED
USDA Natural Resources 'Ieb Sol Sur.'ey 3128/2013
Conservation Service Naborta 'iooe-itive Soil Survey Page 1 of 4
Hydrologic Soil Group—San Diego County Area, California
MAP LEGEND MAP INFORMATION
Area of Interest (AOl) Map Scale: 1:383 if printed on A size (8.5" x 1 1") sheet.
Area of Interest (AOl) The soil surveys that comprise your AOl were mapped at 124,000
Soils - -
Soil Map Units Warning: Soil Map may not be valid at this scale.
Soil Ratings Enlargement of maps beyond the scale of mapping can cause
A misunderstanding of the detail of mapping and accuracy of soil line
placement. The maps do not show the small areas of contrasting
AID soils that could have been shown at a more detailed scale.
• B Please rely on the bar scale on each map sheet for accurate map
BID measurements.
C Source of Map. Natural Resources Conservation Service
CID Web Soil Survey URL: http://websoilsurvey.nrcs.usda.gov
Coordinate System UTM Zone 11 N NAD83
0 This product is generated from the USDA-NRCS certified data as of
Not rated or not available the version date(s) listed below.
Political Features Soil Survey Area: San Diego County Area, California
• Cities Survey Area Data: Version 6, Dec 17, 2007
Water Features Date(s) aerial images were photographed: 6/7/2005
Streams and Canals The orthophoto or other base map on which the soil lines were
Transportation compiled and digitized probably differs from the background
.-+--,- Rails imagery displayed on these maps. As a result, some minor shifting
of map unit boundaries may be evident.
... interstate Highways
_- US Routes
Major Roads
-,, Local Roads
USDA Natural Resources Web Soil Survey 3/28/2013
Conservation Service National Cooperative Soil Survey Page 2 of 4
Hydrologic Soil Group—San Diego County Area, California
Hydrologic Soil Group
Hydrologic Soil Group— Summary by Map Unit - San Diego County Area, California (CA638)
Map unit symbol [ Map unit name Rating [_Acres In AOl Percent of AOl
ExG Exchequer rocky silt loam, 30 to 70
percent slopes
D 0.0 1.5%
SnG San Miguel-Exchequer rocky silt
barns, 9 to 70 percent slopes
D 0.5 98.4%
Totals for Area of Interest 0.6 100.0%
I Description
Hydrologic soil groups are based on estimates of runoff potential. Soils are
I 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.
I The soils in the United States are assigned to four groups (A, B, C, and D) and
three dual classes (AID, BID, 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
I 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 (AID, BID, or CID), the first letter is
I 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
I Aggregation Method: Dominant Condition
I USDA Natural Resources Web Soil Survey 3/28/2013
Conservation Service National Cooperative Soil Survey Page 3 of 4
I
Hydrologic Soil Group—San Diego County Area, California
I Component Percent Cutoff: None Specified
Tie-break Rule: Higher
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Conservation Service National Cooperative Soil Survey Page 4 of 4
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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 % INTER. A B C D
Undisturbed Natural Terrain (Natural) Permanent Open Space 0* 0.20 0.25 0.30
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. Corn) Neighborhood Commercial 80 0.76 0.77 0.78 0.79
Commercial/Industrial (G. Corn) General Commercial 85 0.80 0.80 0.81 0.82
Commercial/Industrial (O.P. Corn) Office Professional/Commercial 90 0.83 0.84 0.84 0.85
Commercial/Industrial (Limited 1.) Limited Industrial 90 0.83 0.84 0.84 0.85
Commercial/Industrial (General I.) General Industrial 95 0.87 0.87 0.87 [j]
*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
San Diego County Hydrology Manual Section: 3 Date: June 2003 Page: 12 of 26
Note that the Initial Time of Concentration should be reflective of the general land-use at the
upstream end of a drainage basin. A single lot with an area of two or less acres does not have
a significant effect where the drainage basin area is 20 to 600 acres.
Table 3-2 provides limits of the length (Maximum Length (LM)) of sheet flow to be used in
hydrology studies. Initial T1 values based on average C values for the Land Use Element are
also included. These values can be used in planning and design applications as described
below. Exceptions may be approved by the "Regulating Agency" when submitted with a
detailed study.
Table 3-2
MAXIMUM OVERLAND FLOW LENGTH (LM)
& INITIAL TIME OF CONCENTRATION (T1'
Element* DU/
Acre
.5% 1% 2% 3% 5% 10%
LM T1 LM T1 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 11.5 85 10.0 100 9.5 100 8.0 100 6.4
LDR 2 50 11.3 70 10.5 85 9.2 100 8.8 100 7.4 100 5.8
LDR 2.9 50 10.7 70 10.0 85 8.8 95 8.1 100 7.0 100 5.6
MDR 4.3 50 10.2 70 9.6 80 8.1 95 7.8 100 6.7 100 5.3
MDR 7.3 50 9.2 65 8.4 80 7.4 95 7.0 100 6.0 100 4.8
MDR 10.9 50 8.7 65 7.9 80 6.9 90 6.4 100 5.7 100 4.5
MDR 14.5 50 8.2 65 7.4 80 6.5 90 6.0 100 5.41 100 4.3
HDR 24 50 6.7 65 6.1 75 5.1 90 4.9 95 4.3 1 100 3.5
HDR 43 50 5.3 65 4.71 75 4.0 85 3.8 95 3.4 100 2.7
N. Corn 50 5.3 60 4.5 75 4.0 85 3.8 95 3.4 100 2.7
G. Corn 50 4.7 60 4.1 75 3.61 85 3.4 90 2.9 100 2.4
O.P./Com 50 4.2 60 3.7 70 3.1 80 2.9 90 2.6 100 2.2
Limited I. _ 50 4.2 60 3.7 70 3.1 80 2.9 90 2.6 100 2.2
General 1. 50 1 3.71 601 3.2 1 70 2.7 80 2.61 90 2.3 100 1.9
*See Table 3-1 for more detailed description
3-12
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