HomeMy WebLinkAboutSDP 2021-0016; CARLSBAD OAKS NORTH, LOT 3; HYDROLOGY AND HYDRAULICS REPORT; 2021-09-02HYDROLOGY AND HYDRAULICS REPORT
DATE 9/2/21
FOR
Lot 3, Whiptail Loop
OWNER:
Tech Contractors c/o Dean Smith
3575 Kenyon St., Suite 200, San Diego, CA 92110
619-223-1663
dean@techbilt.com
LOCATION: Lot 3, Whiptail Loop, Carlsbad, CA 92008
APN : 209-120-02
PREPARED BY:
SPEAR & AS SOCIA TES, INC.
CIVIL ENGINEERS AND LAND SURVEYORS
457 Production Street
San Marcos, CA 92078
Phone: (760) 736-2040
' r L
VI... 1
RECORD COPY
Initial
(
DECLARATION OF RESPONSIBLE CHARGE
I, HEREBY DECLARE THAT I AM THE CIVIL ENGINEER OF WORK FOR THIS
PROJECT, THAT I HA VE EXERCISED RESPONSIBLE CHARGE OVER THE
DESIGN OF THIS PROJECT AS DEFINED IN SECTION 6703 OF THE BUSINESS
AND PROFESSIONAL CODE AND THAT THE DESIGN IS CONSISTENT WITH
CURRENT DESIGN STANDARDS.
I UNDERSTAND THAT THE CHECK OF PROJECT DRAWINGS AND
SPECIFICATIONS BY THE CITY IS CONFINED TO A REVIEW ONLY AND DOES
NOT RELIEVE ME, AS ENGINEER OF WORK, OF MY RESPONSIBILITIES FOR
PROJECT DESIGN.
Danny Abada
Registered Civil Engineer
Spear & Associates Inc.
9/2/21
DATE
r
TABLE OF CONTENTS
I. INTRODUCTION
II. DISCUSSION/CONCLUSION
SUMMARY OF FLOW RATES
ATTACHMENTS
A. LOCATION MAP
B. HYDROLOGY/HYDRAULIC CALCULATION
C. DRAINAGE MAPS
1
1
2
3
5
25
I. INTRODUCTION
This hydrology report is prepared for Lot 3, Whiptail Loop, Carlsbad, CA 92008. APN:
209-120-02
The site is zoned commercial and the project consists of constructing 3 buildings, a
parking lot, underground utilities, covered trash enclosures, landscaping, and two
biofiltration basins for stormwater treatment.
The site has been pre-graded and mostly bare and currently disturbed from its natural
state. The topography slopes southeasterly with elevations ranging approximately
between 373 and 312.
The site drains southeasterly and is intercepted by an existing catch basin and a 60" RCP
on Whiptail Loop per drawing# 415-9. It is then directed to an existing offsite detention
basin, previously designed to attenuate future development increases in flow rate. The
Basin is located west of the project site near the intersection on Faraday Avenue and El
Fuerte Street. (Refer to "Hydrology Study for Carlsbad Oaks North Phase 2, CT
97-13-02" prepared by O'Day Consultants Inc. Dated 11/1/2005 and Revised
7/31/2006).The drainage then continues approximately 0.43 miles north to Agua
Hedionda Creek, then 5.2 miles west to the Pacific Ocean.
The biofiltration basins were designed to address pollutant and hydromodification
controls. Peak flows will be attenuated to pre-development rates by the above mentioned
offsite detention basin.
We have used the County of San Diego Hydrology Manual to determine the run-off from
the site for thel00-year storm event. Based on the soil hydrologic group map, the project
soil uniformly consists of type D across all sub areas. Peak inflow rates were calculated
using the rational method .. Runoff Coefficients for Undeveloped Areas figure 819 .2A
from the Caltrans Storm Water Handbooks was used to evaluate the existing runoff
coefficient because the site was previously graded, is mostly bare and does not conform
to the typical undisturbed natural areas. Times of concentrations were calculated using
the Manning's and Kirpich equations to obtain velocities for average peak Ql00 flow
rates.
II. DISCUSSION/CONCLUSION
This project will not significantly alter existing drainage patterns along the site or divert
runoff from existing conditions. Total post development peak runoff from the site will not
exceed the pre-development rates. The proposed onsite biofiltration basins are designed
to address pollutant and hydromodification controls
The proposed post development source control and treatment control BMPs, as shown in
the stormwater quality management plan, will protect water quality and mitigate water
quality objectives to the maximum extent practicable prior to discharging offsite.
2
Summa
Storm Event 100-year (cft)
Pre-Dev Outlet POC 1 14.4
Post-Dev Outlet POC 1 15.0
Post-Dev POC 1 w/offsite Det. Basin 14.4
2
3
ATTACHMENT A
3
4
LOCATION MAP
(No scale)
4
5
ATTACHMENT B
5
6
Post-Development
REACH TC C
Area A 13.2 0.77
Area B 15.1 0.77
SM 5 0.77
Confluence
Total Flow 15.1
Pre-Development
A
2.72
2.43
0.03
Rational Method, 100yr Event
2.09 2.09 2.92
1.87 1.87 2.92
0.02 0.02 2.92
3.99 2.92
4.11
3.77
7.69
3.77
W/Offsite Det. Basins
Q cfs Q cfs
8.6
7.1
0.2
15.0 14.4
REACH TC C A CA LCA P5 I Q cfs
A 6.03114.4
6
10.0
9.0
8.0
7.0
6.0 J
5.0 )
.,..._
-,-.
i-..,1
i-.. -
i"-..
4.0 >,1 ....
3.0 )
2.0 I
I G> .r.
-~1.0
~0.9
~0.8
.!!lo .E .7
0.6
0.5 i
! 0.4
o.: I
0.2 !
i",.
7
......
........ ."' r-.. i.... . "'
r-.. "'
·t-..
........
...... ..... ... i,.._ .... .... ' .... , .... , ........ ......
.... ...., ... . ' .. ... ..
""'r-.. .... ..
i-.. ... .. • ... .... .. .. r-.. "', ...
... r-.. . ' r-.. " .... .. ..
... , .. .... . ....
... r-.. ..
"'" .......
""""
I 0. . . ' ... 5 6 7 8 9 10 15
.. .... .. .. ~
"" .... .. ~ ~
"'"' .. i. .. ~ ....
"'"' ~
~
"'"
.."'"' i.
~
.... "'
~ .. .. "'~
20 30
Minutes
~
~~
..
~
~
.. ~~
~
~
40 50 1
Duration
EQUATION
I = 7.44 P5 D-0.645
I = Intensity (in/hr)
P5 = 6-Hour Precipitation (in)
D = Duration (min)
~r-.. .... ... .... ' r-.. ," """" .... 1, I• " "" r-.. "'"' ""' .... .. "'~ I• ~ .. ~
1, .... "' .. .. .. .. ~
"'" "'"" ~ "'~ ~~
"r-.. ,. "'i-. ~ ~ ~~~
" .. ~
"t-.. ""'"' ~
r-.. , . "' ~
"'" .... ~~~
1, "', ~~~
" "~ ~~~ I• ..
i-.. .... ..
"'" ~~ ~~
2 3 4
Hours
5 6
a, ± 0 !:;
"ti ci3
6.0 "§:
5.5 ~
5.0 g
4.5 ~
4.0 is
3.5 ~
3.0
2.5
2.0
1.5
1.0
Intensity-Duration Design Chart-Template
Directions for AppllcatJon:
( 1) From precipitation maps determine 6 hr and 24 hr amounts
for the selected frequency. These maps are included in the
County Hydrology Manual (10, 50, and 100 yr maps included
in the Design and Procedure Manual).
(2) Adjust 6 hr precipitation (if necessary) so that it is within
the range of 45% to 65% of the 24 hr precipitation (not
applicaple to Desert).
(3) Plot 6 hr precipitation on the right side of the chart.
(4) Draw a line through the point parallel to the plotted lines.
(5) This line is the intensity-duration curve for the location
being analyzed.
Appllcatlon Form:
(a) Selected frequency~ year
(b) p = 2 . 9 2in. p = 4 . 9 2 ~ = 5 9 %(2) 6 --• 24 --•p --
(c) Adjusted p6<2> = 2.92 in.
24
(d) lx = __ min.
(e) I= ___ in./hr. (see I values in previous page)
Note: This chart replaces the Intensity-Duration-Frequency
curves used since 1965.
,--
IP6 1 1.5 2 2.5 3 3.5 4' 4.5 1 5 : 5.5 I 6
Duration ' I '. I -, I I I I I I I I I
5 2.63 3.9515.2716.59 j7,~~.22 _10.54~1-~1;!.1?[14.49 15.81
7 2.12 3.18l4.2◄1 5.30 6.36 7.42 8.48 1 9.~_r-10.60 11.66 12.72
,_ 10 1.68 2.53 3.3714.21 5.0515.90 6.74 . 7.58 8.42 9.27 10.11
15 1.30 1.95 2.59 3.24 3.89 4.54 5.19 5.84 6.49 7.13 7.78
20 1.os 1.62 2.1512.69 3.23. 3.n 4.31 , 4.85 5.39 5.93 6.46
25 0.93 !:_40 1.87+g.33t2.80_2:.2?: ~7~_j 4JO .~.67 5.13 5.60_ ~ 0.83 11.24 1,6612,07 2.49 2.90 3.32,_p .73__(_4.15 4.56 4.98
_o.69_ji 03 1.384 1.12 2.01-:-2.41 ~1~-t3J o L 3 .. ~5 ug_ '--"· 13
_Q.604 0,9_0 1,_:1911.49 1.79 2.09 2~,_6~~98 3.28 3.5!
0.53 0.80 1.06 1.33 1.59 1.86 2.12 . 2.39+2.65 2.92 3. 18
90 0 .41 • 0.61 0.82. 1.02 1.23. 1.43 1.63 . 1.84 2.04 2.25 2.45
120 0.34 0.51 0.68 0.85 1.02 1.19 1.~ 1.70 1.87 2.04
150 0.29 0.44 0.591 0.7310.88 1.03 1.18 1032 1,47 1.62 1.76
180 0.26 0.39 0.5210,§5~._0Jl_!J ::ffi04 1.:1!~ ~44__...!,~
240 0.22 0.33 0.4310.54 0.65 O~..Q-87 0.98 _ 1.08 1.19 1.30
300 0.19 0.28 0.38 0.477 0.56 0.66 0.75 0.85 0.94 1.03 I 1.13
-360 ·o. 1710.25 0.331 0.42 I 0.50 0058 _ 0.67 0. 75 0.84 0,92 l 1.00
FIGUR E ~
8
M Gmail Danny Abada <dannyabada@gmall.com>
RE: PDS2016-LDGRMN-20115
1 message
Bayona, Joshua <Joshua.Bayona@sdcounty.ca.gov> Thu, Aug 23, 2018 at 7:52 AM
To: Danny Abada <dannyabada@gmail.com>
Cc: Mark Farrington <mark@farringtonengineering.com>, Josh Zeigler <josh@spearinc.net>
Hi Danny,
I coordinated with County staff about your question regarding the use of the precipitation values from
NOAA. The County will be fine with the use of precipitation values directly from NOAA as you had done
in the previous review.
Thank you,
Joshua Bayona
Assistant Engineer
Qtountp of ~an lhego
Planning & Development Services (PDS)
Land Development -Engineering Division
5510 Overland Ave, Ste 310
San Diego, CA 92123-1239
0 : (858) 495-5454
Joshua.Bayona@sdcounty.ca.gov
Mon-Thurs: 7am-4:30pm
Fri: 7am-11am
http://www.sdcounty.ca.gov/pds/LandDevelopment.html
8
6/1/2021
I
9
Precipitation Frequency Data Server
NOAA Atlas 14, Volume 6, Version 2
Location name: Carlsbad, California, USA*
Latitude: 33.1408°, Longitude: -117.2561°
Elevation: 325.29 ft ..
• source: ESRI Maps •• source: USGS
POINT PRECIPITATION FREQUENCY ESTIMATES
Sanja Perice, Sarah Dietz, Sarah Helm, Lillian Hiner, Kazungu Maitarla, Deborah Martin, Sandra Pavlovic, lshanl Roy, Carl Trypaluk, Dale Unruh, Fenglln Yan, Michael Yekta, Tan Zhao, Geoffrey
Bonnin, Daniel Brewer, U-Chuan Chen, Tye Parzybok, John Yarchoan
NOAA. National Weather Service, Silver Spring, Maryland
Pf tabular I .PL9ra~ I Maps & aerials
PF tabular
PDS-based point precipitation frequency estimates with 90% confidence intervals (in inches)1
Average recurrence interval (years)
1 2 II 5 10 25 II 50 II 100 II 200 II 500 II 1000
I
I !Duration II II II II 8 0.122 0.154 0.198 0.236 0.290 o.333 I o.380 I 0.431 0.503
l(o.~;:33)1 0.103-0.1461 110.129-0.165 110.166-0.239} 0.196-0.2871 0.232-0.365 0.261-0.430} :(0.290-0.503): 0.319-0.587 0.357-0.717'
~ 0.175
1(0.1 ~~is5) ll(o.2~214342) I 0.338 0.415 0.478 0.545 0.617 0.721 0.808
0.147-0.2101 '0.261-0.4111 0.333-0.523 0.375-0.616} 0.416-0.721\ 110.457-0.641 10.511-1.03\ (0.552-1.19} B 0.211 0.267 I 0.343 I 0.409 0.502 0.578 0.659 0.746 0.872 0.9n
o.178-0.253) l(0.224-0.321 :(0.288-0.414): 0.340-0.497} 0.403-0.633 0.453-0.7451 0.503-0.671} (0.553-1.02) (0.618-1.24 l (0.667-1.44)
130-min I 0.300 0.378
l10.4~~~il
0.580 0.712 0.820 0.934 I 1.06 I 1.24 1.39
0.252-0.359) 0.318-0.455) 0.482-0.704\ 0.571-0.897' 10.642-1.06) 10.713-1.24) : (0.764-1.44): (0.677-1.76) (0.946-2.05)
J 60-mln I o.431 I 0.544 I 0.100 0.833 1.02 1.18 1.34 II 1.52 II 1.78 1.99
0.363-0.517) :(0.458-0.654) : '0.587-0.643) (0.692-1.01) (0.621-1.29) (0.924-1.52) (1.02-1.76) :: (1 .13-2.07) :: (1.28-2.54) (1.36-2.94)
G l(o.~~25)1 0.6~:.~~10
0.966 1.14 I 1.40 1.60 1.82 II 2.05 II 2.39 2.67
(0.810-1.16) (0.951-1.39\ : (1.12-1.76) (1.25-2.06) (1.39-2.41) :: p .52-2.80) .. (1.70-3.41) (1.83-3.95) G 0.729 0.913 1.16 I 1.37 II 1.67 1.92 2.11 r#t E 2.45 2.84 3.17
0.614-0.875) (0.767-1.10) (0.975-1 .40) : (1.14-1.67) :: (1.34-2.11) (1.50-2.47) 11.66-2.8 (1 .61-3.34) (2.01-4.05) (2.16-4.66) B 0.989 1.24 1.58 II 1.87 I 2.21 2.59 2.92 ~ 3.28 3.78 4.20
(0.633-1.19) (1.04-1.49) (1.33-1.90) :: (1.55-2.27) : (1.62-2.65\ (2.03-3.33) (2.23-3.86) 12.4:U,47) (2.66-5.39) (2.87-6.21)
~I (1.~1~
1
581
1.66 2.12 II 2.so 3.02 3.44 3.87111 z 4.32 4.96 I 5.46
(1.39-1.99) (1.TT-2.55) :: (2.08-3.04) (2.42-3.61 l (2.70-4.43) 12.95-5.1 '<3.20-5.89) (3.51-7.06) . (3. 73-8.08)
I 24-hr II (1.4~~~91)
2.10 2.69 II 3.18 3.86 II 4.38 4.92""' 5.48 6.25 II 6.86
(1.65-2.43) (2.37-3.13) :: (2.78-3.72) (3.26-4.65) :. (3.63-5.39) (3.96-6.19) (4.32-7.06\ (4.74-8.41) (5.04-9.54)
I 2-day II (1.:o~2~35)
2.61 3.37 II 3.99 4.85 5.52 II 6.21 6.92 7.91 II 8.70
(2.30-3.02) (2.96-3.91) " (3.48-4.67) (4.10-5.85) (4.57-6.79) (5.03-7.82) (5.46-8.95) (6.00-10.6) (6.36-12.1)
I 3-day II (2.;1~2~63)
2.93 I 3.80 4.52 5.51 6.29 II 7.08 7.91 9.06 II 9.97
(2.59-3.40) . (3.34-4.41) (3.94-5.29) (4.68-6.65) (5.21-7.74) (5.74-8.92) (6.24-10.2) (6.87-12.2) (7.32-13.9)
8 l 2.so II 3.23 II 4.20 5.01 6.12 6 .99 II 7.89 8.82 II 10.1 II 11.1
: (2.20-2.89) .. (2.85-3.74) :: (3.70-4.88) (4.37-5.86) (5.17-7.39) (5.79-8.60) (6.39-9.93) (6.96-11.4) :. (7.68-13.6) .. (6.19-15.5)
I 7-day 11 (2.:7~3~36) II (3.:5~~40) 11 (4.::;!~78)
5.96 7.31 8.37 9.48 10.a I 12.2 13.5
(5.20-6.97) (6.18-8.82) (6.94-10.3) (7.68-11 .9) (8.39-13.8) : (9.26-16.5} (9.93-18.8)
I 1°-day II ,2.i4~3~72)
4.23 II 5.58 6.69 I 8.24 I 9.46 10.7 I 12.1 II 13.9 15.4
(3.73-4.90) :: (4.90-6.47) (5.64-7.63) . (6.97-9.94 l . (7 .64-11.6) (6.69-13.5) . (9.52-15.6) .. (10.6-18.7) (11.3-21.4)
I 2°-day II (3.:6~~53) s.21 II 6.93 8.37 II 10.4 II 12.0 13.6 II 15.4 II 17.9 19.9
(4.59-6.03) :: (6.09-8.04) (7.30-9.79) :: (8.77-12.5) :: (9.91-14.7) (11.0-17.2) :· (12.1-19.9) :: (13.6-24.1) (14.6-27.7)
130-day II (4.;4:5~44) 6.27 II 8.38 10.1 II 12.a II 14.6 16.7 II 18.9 II 22.1 II 24.7
(5.53-7.26) :: (7.37-9.73) (6.85-11.9) :: (10.7-15.2) :: (12.1-18.0) (13.5-21.0) :: (14.9-24.5) :: (16.8-29.7) .. (18.1-34.3)
J 45-day 11 (4.9
5
2~:.441 I (6.~~~60) II (8.::3~1~.5) 12.1 II 15.0 II 17.5 20.0 II 22.8 II 26.8 II 30.1 (10.5-14.1) :: (12.7-18.2) :: (14.5-21 .5) (16.2-25.2) :: (18.0-29.5) :: (20.3-36.0) :: (22.1-41.8)
I so-day II !5,::3~7°52) II !7,:9~9~98) II (10
1
1\;.4) 14.0 II 17.5 II 20.3 I 23.4 II 26.7 II 31.6 II 35.6 (12.2-16.3) :: (14.8-21.1) :: (16.9-25.0) (18.9-29.5) :: !21.1-34.6) :: (23.9-42.5) :: (26.1-49.5)
1 Precipitation frequency (PF) estimates in this table are based on frequency analysis of partial duration series (PDS).
Numbers in parenthesis are PF estimates at lower and upper bounds of the 90% confidence interval. The probability that precipitation frequency estimates (for a
given duration and average recurrence Interval) will be greater than the upper bound (or less than the lower bound) Is 5%. Estimates at upper bounds are not
checked against probable maximum precipitation (PMP) estimates and may be higher than currenUy valid PMP values.
Please refer to NOAA AUas 14 document for more information.
Back to Top
PF graphical
9
https://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=33.1408&Ion=-117 .2561 &data=depth&units=english&series=pds
I
1/4
6/1/2021
10
40
35
§ 30
.t::. 25 .., c.. Qj
"O
C: 20 0 ·.;:;
tQ ..., 15 ·a. ·o
Qj ... 0.. 10
5
0 C: ·e
J,
40
35
;g 30
.t::. .... c.. 25
Qj
"O
C: 20 0 ·.;;
2 ·a. 15 ·o
~ 0.. 10
5
0 1
Precipitation Frequency Data Server
PDS-based depth-duration-frequency (DDF) curves
latitude: 33.1408", Longitude: -117.2561"
. . . . . . .
• I I • I t • • I ' • • ' • ' ... ·:· ... :· .. -.. : .. -. -·: .... -·:. -. : ..... : ..... ·:· . -... : ... -. : .. ·:-. ·:. -.. -: . -:-.. -. ·:· .. : ... : . . . ' ' ' . ' ' . ' . . .... : ... -r-..•. ~ ..... ~--... .; ... ; ....... -:-.... -:-.. ---~---· .; ... : .... : .... ~--.: ...... :---~--.
• t ' ' I I ' . . . . . . ' . . ' . ' . . . ' ' . . ' . ' ' ' . ' ' . . ' . ' . ' . ' • • • • •• • • • ,-• • • • • I • • • • • , • • • • • .. • • • 1 ' • • • • .. • • • o • ••• • • • • • ,,_ • • • • ~ • • ••• • ... • o • • ... • ••• • • • • • ,-• • • I : : : . ' : ' : : . ' ' : : .
• I t I I • ' ' ' . . ' . ' ' . ' . . ' . . . . . . .....................................................................................
t I t O l t I I I I : : : : : : : : : :
I O • I I • • • I . . ' . . ' . ' . . ' ' .. . -.. :· .. -:· .. -. -: ... -. ·: · -... : ... : ... -. ·:-. ---. ~-... -. :· -.... : ... :· . ·: -. -. -: . . ' . ' . . . ' . ' . ' . . ' ' . . .. . ' . . ' ' . ' ' • ' • l • t I .... , .... , ..... , ..... ,., ........ , ..... , ...... , ...... , . .
' ' ' . . ' . •••• , •••• , •• -•••• ---...... --~' •• 1 -•••• , ••
C: C: C: C: ... ... ... ... ... >, >, >, >, >, >, >, >, >, ·e ·e ·e ·e .t::. .c .c .t::. .t::. tQ tQ tQ tQ tQ tQ tQ tQ tQ N ,1,., ,J, :::I -0-"O "O "O "O "O "O "9 "O"O
0 :!I g ~ N N "" -¼ ~o I ~s 0 ~ ~ ~ N Duration
. ' ' ' . ' . ······<········-···:-·······!···········:·-···-···:·········:···•··••;-••··-·····:··--·· . . . . ' . . ' . . ' I I I I • . . . . . ·····••:--•·······••:••····-·1·······-···!··-····••:-••·-·••·:--•··· ·!
' . ' ' . ··············•····,······-·············,. ............. . I I t I •
' . ' ' ' ~ . . ' ' . ' . . . ....... ,. --·---.. -..... -........ -............. . . . ' .
' ' I ' . . . . . . . . .
2 5 10 25 so 100 200 500 1000
Average recurrence interval (years)
NOAA Atlas 14, Volume 6, Version 2 Created (GMT): Tue Jun 118:28:21 2021
Back to TOR
Maps & aerials
Small scale terrain
Average recurrence
interval
(years)
-1
2
-5
-10
-25
-50
-100
-200
500
-1000
Duration
fH'nln -2-<lay
1G-fflln -3-<lay
15-mln -4-<lay
-3G-fflln -7-<lay
-6G-ffl1n -10-<lay
-2~r -20-<lay
-3~r -30-<lay
-6~r -45-<lay
-12~r -60-<lay
-24-tir
10
https://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=33.1408&Ion=-117 .2561 &data=depth&units=english&series=pds 214
6/1/2021
11
Precipitation Frequency Data Server
~,r..~
c,o/
non~ v.,\,~ lrt:1 ,I '"/ttJ,1/it " Id/IP-Olli
ta wirnar.a
Oxnard 0
....
3km
I
100km
I I 60ml
Large scale aerial
Em,ttnada p
https://hdsc.nws.noaa .gov/hdsc/pfds/pfds _printpage. html?lat=33.1408&Ion=-117 .2561 &data=depth&un its=english&series=pds
11
3/4
6/1/2021
12
Precipitation Frequency Data Server
Back to TOQ
.\.!.S...Q!lpartment of Commerce
National Oceanic and Atmospheric Administration
National Weather Service
National Water Center
1325 East West Highway
Silver Spring, MD 20910
Questions?: HDSC.Questions@noaa.gID'.
Disclaimer
https://hdsc.nws.noaa.gov/hdsc/pfds/pfds_prinlpage.html?lat=33.1408&Ion=-117 .2561 &data=depth&units=english&series=pds
12
4/4
13
Sm Diego Comty Hydrology :Mmmal
~: June 2003
Section:
Page:·
Table3-l
RUNOFF COEFFICIENTS FOR URBAN AREAS
LmdU!ie I Rlmoff Coefficient "C''
SailT\~
NR.CSEJemencs 0 El~ %IMPER. A B
Undistmhed Nalma1 Terrain (Natural) llemwJentOpenSpac.e ~ 020 0.25
Low µensity~!lidemial(IDR} R:esi9PDDaJ, 1.0 DU/A« less 10 0.27 0.32
Low .?ensitY ~!lidenlial (IDBJ R:esic)pntjaI· 2.0 DU/A« less • J 20 034 0.38
Low Density Besidenlial (IDR} R.esidemia!, 2.9 DU/A or ],ess 25 038 0.41
Medimn-Dtms.ityResidimtial (MDR) ResicJeutia1., 43 DU/Aocl;ess 30. 0.4) 0.45
Medium Density ResicJeutiat (MDR) Residential. 7.3 DUlAocless 40 0.48 0.5l
Medium Demily Resicfeutiid {MDR) Residential, 10.9 DU/A or less 45 0.52 0.54-
Medium Density R:esiclential (YDR) Res.Jtb!n:ti:a~ 14.5 DU/A oc less 50 0.55 0 .58
High Density RPSidentitl (HOR) Resicfenti:11, 24.0 DU/A oc less 65 0.66 0 .61
High Density :R.esiderIN) (HDRJ Res;cJeutw, 4l.ODU/Aoc less 80 0.76 0.77
C'omml!niallind ~-Com) Neighbamood Commertial 80 0.76 0.77
CommemalllDdnstr {G. Com) General Cammm:ia1. &5 0.30 0.80
Cammerciallmdu.s (O.P. Com) Office Pmfl!ssim11liComm!n:ial 90 0.83 0.84
CommeJcialliadu {LimilN. l.) Limned IDdnstrial 90 0..83 0.84
~(GrmlL) General lDdnstrial 95 0.87 0.87
C
0.3-0
0.36
0.42
0.45
0.48
0.54
0.57
0.60
0.69
0.7&
0.78.
O.Bl
0.84
0..84
O.Jt7
3
6 of1.6
D
0.35
0.41
0.46
0.49
0.52
0.57
0.60
0.63
0.71
0.79
0.19
0..12
{l.8.5
0.85
0..&1
•'lbevames aswci•fJ!d 111:itb 0% impemous may be 11SM ·for ditKt cak:ulatimi. of the nmoff cnefficieot P5 descn.1,ed in. Section 3.1.2 (~ tbe pm;iaos nmoff
coeffic.iellt, Cp, JiJr: tl!le sail type-), or fur areas that will remain midwurbed :in perpetuity. Just:ifiaticm. nmst be giVl!D that the area will .remain lW1Jial mn!W£ (e.g., the UH
is lociued.in. Clewlmd Natimal Farnt).
DUJA = cm-elling mms per-am
NH.CS= Natimal Resalmi!S Camenratio:n ServiC2
u 13
14
BMP Sizing Calcu'lator
HYDRO UNIT NAME CARLSBAD
HYDRO i\REA, NAME Agua Hedionda
HYDRO SUBAREA NAME Los Monos
HYDRO BASIN NUMBER 904.31
HYDRO SOIL GROUP D
RAIN GAUGE BASIN Oceanside Basin
Zoom to
14
15
Runoff Coefficient Adjustment
Post Development Area
Total Area
lmperviuos Area
225775
151060 66.91 %
C = 0.90 x (% Impervious) + Cp x (1 -% Impervious)
% impervious = 66.91%
Cp = 0.35 (Table 3.1, soil type D, 0% impervious, County Hydrology Manual)
C = 0.72
15
16
Relief
Soil
Figure 819.2A
Runoff Coefficients for Undeveloped Areas
Watershed Types
Extreme High Normal
.28 -.35 .20 -.28 .14 -.20
Steep, rugged terrain Hilly, with average Rolling, with average
with average slopes slopes of IO to 30% slopes of 5 to 10%
above 30%
Low
.08 -.14
Relatively flat land,
with average slopes
ofO to 5%
Infiltration .12 -.16 .08 -.12 .06 -.08 .04-.06
Vegetal
Cover
Surface
Storage
Given
Find
No effective soil Slow to take up Normal; well drained High; deep sand or
cover, either rock or water, clay or light or medium other soil that takes
thin soil mantle of shallow loam soils of textured soils, sandy up water readily,
negligible low infiltration loams, silt and silt very light well
infiltration capacity capacity, imperfectly loams drained soils
or poorly drained
.12 -.16 .08 -.12 .06-.08 .04 -.06
No effective plant Poor to fair; clean Fair to good; about Good to excellent;
cover, bare or very cultivation crops, or 5 0% of area in good about 90% of
sparse cover poor natural cover, grassland or wood-drainage area in
less than 20% of land, not more than good grassland,
drainage area over 50% of area in woodland or
good cover cultivated crops equivalent cover.
.10 -.12 .08 -.10 .06 -.08 .04-.06
Negligible surface Low; well defined Normal; High; surface stor-
depression few and system of small considerable surface age, high; drainage
shallow; drainageways; no depression storage; system not sharply
drainageways steep ponds or marshes lakes and pond defined; large flood
and small, no marshes plain storage or large
marshes number of ponds or
marshes.
An undeveloped watershed consisting of; Solution:
I) rolling terrain with average slopes of 5%, Relief 0.14
2) clay type soils, Soil Infiltration 0.08
3) good grassland area, and Vegetal Cover 0.04
4) normal surface depressions. Surface Storage 0.06
C= 0.32
The runoff coefficient, C, for the above watershed.
Pre-Developed Project Conditions: (Site Previously Graded & Mostly Bare)
Relief (1.9%) = 0.1
Soil Infiltration (type D) = 0.14
Vegetal Cover (mostly bare)= 0.12
Surface Storage (negligible)= 0.1
Pre-Development Runoff C = 0.46
16
17
Initial
A
Location slope% Initial L (ft)
Pre Dev. 50
Post Dev.
DMAA 0.6
DMAB 0.6
Initial Travel Time
(Figure 3-3)
T min= 1.8(1.1-C}D112
5113
100
60
60
Overland Flow (Pre-Development)
Kirpich Formula
Tc min= (11.9L3/L'lE)°-385
'--)
Initial
Travel T'
T (min)
3.1
6.3
6.3
Initial TC
C=
D ft=
S%=
T=
Time of Concentration
A
Add'I L (ft) slope% Notes
560 2.5 Kirpich Formula
500 0.6
630 0.6
Pre-Dev Post-Dev
DMAA
0.46 0.72
100 60
50 0.6
3.13 6.28
Pre-Dev
L'lE ft= 14
L Feet= 560
L miles= 0.106061
T hours= 0.070363
Tmin = 4.22
J
Average Q Additional TC
V (ft/s) T (min)
4.2
1.2 6.9
1.2 8.8
DMAB
0.72
60
0.6
6.28
Total
TC
T (min)
(5 minutes mi1 n)
7.3
13.2
15.1
17
J
~ (X)
tii w LL
~ w (.) ~ i5
w ~ :::, 0 C) a: w i
30
IB 5 z
20 ~
~ w :;
i==
~ _,
u.
--10 ~
----:5 a: ~
---0
EXAMPLE:
GiVen: Watercourse Distance (DJ = 70 Feet
Slope (s) = 1.3%
Runoff Coefficient (C) = 0.41
Overtand Flow Time (T) = 9.5 Minutes
T= 1.8(1.1-C)Vo · 'v-s·
SOURCE: Airport Drainage, Federal Aviation Administration, 1965
Rational Formula • Overland Time of Flow Nomograph
FIGURE
~ l~l
~
(X)
19
.6. E
Feet
5000
4000
EQUATION
Tc = (1~~3)°.385
Tc
L
.6.E
= Time of concentration (hours)
• Watercourse Distance (miles)
= Change In elevation along
effective slope line (See Figure 3-S)(feet)
.6.E
3000
2000
1000
0
' 500' ' 400 '
300
200
100
30
20
10
5
'~~ ~~ "~ ' ' ' ' ' ' ' '
L
MIies Feet
'1
' 3000
0.5 '
2000
1800
1800
1400
1200
1000
900
800
700
600
500
400
300
200
L
' ' '
Tc
Hours Minutes
4
3
2
' ' '
Tc
50
40
30
20
18
HS
14
12
10
9
8
7
6
5
4
3
SOURCE: California Division of Highways (1941 ) and Kirpich {1940)
Nomograph for Determination of
Time of Concentration (Tc) or Travel Time (Tt) for Natural Watersheds
FIG U R E
~ 19
Channel Report
Hydraflow Express Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc.
Post Dev Area A TC Velocity, Average Q
User-defined
Invert Elev (ft) = 9.72
Slope(%) = 0.60
N-Value = 0.018
Calculations
Compute by: Known Q
Known Q (cfs) = 4.30
(Sta, El, n)-(Sta, El, n) ...
(-20.00, 10.00)-(1.50, 9.72, 0.016)-(3.00, 9.80, 0.016)-(23.00, 10.00, 0.018)
Elev (ft)
11 .00
10.50
10.00
9.50
9.00
--------r----
-5
Section
--
v-
0
Sta (ft)
5
Highlighted
Depth (ft)
Q (cfs)
Area (sqft)
Velocity (ft/s)
Wetted Perim (ft)
Grit Depth, Ye (ft)
Top Width (ft)
EGL (ft)
~ ----L..----
10 15 20
Thursday, Jun 3 2021
= 0.25 = 4.300
= 3.52
= 1.22
= 37.01
= 0.23
= 37.00
= 0.27
25 30
20
Depth (ft)
1.28
0.78
0.28
-0.22
-0.72
Channel Report
Hydraflow Express Extension for AutoCAD® Civil 30® 2009 by Autodesk, Inc.
Post Dev Area B TC Velocity, Average Q
User-defined
Invert Elev (ft) = 9.72
Slope(%) = 0.60
N-Value = 0.018
Calculations
Compute by: Known Q
Known Q (cfs) = 3.50
(Sta, El, n)-(Sta, El, n) ...
(-20.00, 10.00)-(1 .50, 9.72, 0.016)-(3.00, 9.80, 0.016)-(23.00, 10.00, 0.018)
Elev (ft)
11.00
10.50
10.00
Section
-.... -
Highlighted
Depth (ft)
Q (cfs)
Area (sqft)
Velocity (ft/s)
Wetted Perim (ft)
Crit Depth, Ye (ft)
Top Width (ft)
EGL (ft)
----------------~ ----V
9.50
9.00
-5 0 5 10 15 20
Sta (ft)
Thursday, Jun 3 2021
= 0.23 = 3.500
= 2.82
= 1.24 = 33.01 = 0.22
= 33.00
= 0.25
25 30
21
Depth (ft)
1.28
0.78
0.28
-0.22
-0.72
Channel Report
Hydraflow Express Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. Thursday, Jun 3 2021
Basin A Q100 Outlet Pipe
Circular Highlighted
Diameter (ft) = 1.50 Depth (ft) = 1.04
Q (cfs) = 8.600
Area (sqft) = 1.31
Invert Elev (ft) = 100.00 Velocity (ft/s) = 6.57
Slope(%) = 1.00 Wetted Perim (ft) = 2.95
N-Va lue = 0.013 Crit Depth, Ye (ft) = 1.14
Top Width (ft) = 1.38
Calculations EGL (ft) = 1.71
Compute by: Known Q
Known Q (cfs) = 8.60
Elev (ft) Section
0 2 3
22
Reach (ft)
Channel Report
Hydraflow Express Extension for AutoCAD® Civil 30® 2009 by Autodesk, Inc. Thursday, Jun 3 2021
Basin B Q100 Outlet Pipe
Circular Highlighted
Diameter (ft) = 1.50 Depth (ft) = 0.91
Q (cfs) = 7.100
Area (sqft) = 1.13
Invert Elev (ft) = 100.00 Velocity (ft/s) = 6.30
Slope(%) = 1.00 Wetted Perim (ft) = 2.68
N-Value = 0 .013 Crit Depth, Ye (ft) = 1.04
Top Width (ft) = 1.46
Calculations EGL (ft) = 1.53
Compute by: Known Q
Known Q (cfs) = 7 .10
Elev (ft) Section
100.50
0 2 3
23
Reach (ft)
Channel Report
Hydraflow Express Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. Thursday, Jun 3 2021
Total Q100 Outlet to Whiptail L. (exist. 24in to 60in)
Circular Highlighted
Diameter (ft) = 2.00 Depth (ft) = 1.19
Q (cfs) = 15.00
Area (sqft) = 1.95
Invert Elev (ft) = 100.00 Velocity (ft/s) = 7.68
Slope(%) = 1.00 Wetted Perim (ft) = 3.53
N-Value = 0.013 Crit Depth, Ye (ft) = 1.40
Top Width (ft) = 1.96
Calculations EGL (ft) = 2.11
Compute by: Known Q
Known Q (cfs) = 15.00
Elev (ft) Section Depth (ft)
0 2 3
24
Reach (ft)
25
ATTACHMENT C
(
(
25
§
~
"
-~ ~~ '-:::,
30 15 0 30 60 90
SCALE: 1 " 30'
PLANS PREPARED BY:
SPEAR & ASSOCIATES, INC-
c1v1L ENGINEERING & LAND SURVEYING
475 PRODUCTION STREET, SAN MARCOS, CA 92078
PHONE (760) 736-2040 FAX (760) 736-4866
WWW.SPEARINC.NET
~
I I
• I
I
IMPERVIOUS AREA (PRE-CONSTRUCTION)
EXISTING IMPERVIOUS AREA
{TO BE REMOVED} 14,700 SQ FT
LEGEND OF SYMBOLS ---------PROPERTY LINE
(
STREET CENTERLINE
EXISTING CONTOURS
DIRECTION OF DRAINAGE
DRAINAGE AREA
DRAINAGE MANAGEMENT AREA DESIGNATION
LONGEST FLOW PA TH
PROJECT ADDRESS:
LOT 3, WHIPTAIL LOOP
CARLSBAD, CA 92008
OWNER:
NAM£: TECH CONTRACTORS
ADDRESS: 3575 KENYON STREET, SUIT£ 200 .
SAN DIEGO, CA 92110
CONTACT: DEAN SMITH
PHONE NO: {619) 223-1663
I SH1EET I CITY OF CARLSBAD I SH1EETS I
ENGINEERING DEPARTMENT
PRE DEVELOPMENT DMA PLAN FOR: DRAWING NO.
LOT 3, WHIPTAIL LOOP
CARLSBAD, CA 92D08 PRE
C ~~~
0 L....:..:. ____ _:"::::~:::;e-s:2~:::::::::..:..:::z:_ _________________________________________________________________________________________________ ~==================~ ~
~
------
----------
I
-------
-:........_
~r ¾I, --~
JO 15 0 30 60 90
SCALE: 1 ,, 30'
PLANS PREPARED BY:
SPEAR & ASSOCIATES, INC.
CIVIL ENGINEERING & LAND SURVEYING
475 PRODUCTION STREET, SAN MARCOS, CA 92078
PHONE (760) 736-2040 FAX (760) 736-4866
WWW.SPEARING.NET
~
WHIPTAIL LOOP
* MINIMUM CURB DEPTH IS 12 INCHES; CURBS SHOULD BE
VERTICAL ELBOW DOWE/£D TWO FEET INTO ADJACENT PCC
PAVEMENT WffHIN 10 FEET OF THE BIOFILTRATION BASIN. 3• HARDWOOD MULCH
MAINTENANCE CLEAN-OUT
CATCH BASIN EMERGENCY OVERFLOW
STORM DRAIN STENCIL SD-13
3.00'{MIN.} BENCH I
:a: c:, ,.,Cl:' ~,'§
-e:i C, r;::; ~ B:
-BASIN TOP (MIN.)
{TO REMAIN CLOSED AT ALL TIMES}
6" MIN. FROM F.S. OF BASIN
6" P.C.C. CURB PER SDRSD G-1
TYPICAL DETAIL & OUTLET CONNECTION
NOT-TO-SCALE
COREDRILL KEYHO/£ TYPE OPENING
FOR MAINTENANCE PLATE REMOVAL
WITHOUT REMOVING THE BOLTS
12x12" PLATE
-...-½ x4" STAINLESS STEEL
WEDGE ANCHOR BOLT
¾ • THICK GALVANIZED
MAINTENANCE PLATE
/ ~ ~ '--EPOXY SEAL TO CATCH j [;j' BASIN INTERIOR WAU
( i., [g \_-1-5• DIA. PERFORATED
8 I\ ~// 8 P1'!7 UNDERDRAIN , / CONNECTION I (EXTERIOR}
ORIFICE DRIUED THROUGH MAINTENANCE
PLATE@ UNDERDRAIN CONNECTION.
A= 1.68: B= 1.59"
MAINTENANCE PLATE DETAIL
ATTACH TO INTERIOR INLET WAU OF
36x36" CATCH BASIN
DRAINAGE MANAGEMENT AREA BREAKDOWN
DRAINAGE AREA SURFACE SYMBOL
SOIL TYPE
BUILDING ROOFTOP ~
PARKING/DRIVE A/SI£
IMPERVIOUS AREA
HARSCAPING/SIDEWALK
LANDSCAPING
DMA SUB-AREA:
TOTAL SITE AREA:
I .. · .. ·1· .. -. . . . ... -. --. . . . . . .
DRAINAGE AREA if DRAINAGE AREA ·a· SELF MmGATING
35,256 SQ FT 20,380 SQ FT 0 SQ FT
41,059 SQ FT 42,495 SQ FT 0 SQ FT
4,705 SQ FT 7,165 SQ FT 0 SQ FT
37,345 SQ FT 35,860 SQ FT 1,510 SQ FT
118,365 SQ FT 105,900 SQ FT 1,510 SQ FT
225,775 SQ FT
I
I !
I
LEGEND OF SYMBOLS
---------PRDPERTY LINE
---
(
@
ml------>
STREET CENTERLINE
EXISTING CDNTDURS
DIRECTIDN DF DRAINAGE
DRAINAGE AREA
DRAINAGE MANAGEMENT AREA DESIGNATIDN
LDNGEST FLDII PA TH
PRDPDSED STURM DRAIN
& CATCH BASIN <PVT>
PROJECT ADDRESS:
LOT 3, WHIPTAIL LOOP
CARLSBAD, CA 92008
PROPERTY OWNER
CARLSBAD OAKS NORTH VENTURES LP.
ADDRESS: 3575 KENYON STREET, SUITE 200
SAN DIEGO, CA 92110
CONTACT: DEAN SMITH @TECH CONTRACTORS
PHONE NO: (619) 223-1663
I SH1EET I CITY OF CARLSBAD I SHEETS I
ENGINEERING DEPARTMENT 1
POST DEVELOPMENT DMA PLAN FOR:
LOT 3, WHIPTAIL LOOP
CARLSBAD, CA 92008
DRAWING NO.
POST
0 ,;L~----:--~::z::::=,...:..:::s:::__ _____________________________________ ____.!:::=::=::=::=::==:=::=~
a