HomeMy WebLinkAboutMS 16-05; 1284 PINE AVE; FINAL DRAINAGE STUDY; 2019-11-05FINAL DRAINAGE STUDY FOR
PARCEL MAP MS16-05
1284 PINE AVENUE, CARLSBAD 92008
DWG 518-7A / GR201 9-0024
APN 205-020-57
In The
CITY OF CARLSBAD, CA
Prepared For
1284 PINE PARTNERS, LLC
1284 PINE AVENUE
CARLSBAD, CALIFORNIA 92Ocr lemul
NOVEMBER 5, 2019
MOD IODM
William C. Hobbs L..- RCE 42265
W. C. HOBBS, CONSULTING ENGINEER
33892 COPPER LANTERN, UNIT A
DANA POINT, CALIFORNIA 92629
951.660.9800
wchobbs@wwdb.org RECEIVED
DEC 04 2019
LAND DEVELOPMENT
ENGINEERING
DECLARATION OF RESPONSIBLE CHARGE
I HEREBY DECALRE THAT I AM THE CIVIL ENGINEER OF
WORK FOR THIS PROJECT, THAT I HAVE EXERCISED
RESPONSIBLE CHARGE OVER THE DESIGN OF THIS
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, SPECIFICATIONS AND TECHNICAL
STUDIES 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.
oss IQ'
CiN
NO. 42265
C I v %
OF CP'
RCE 42265
PURPOSE OF PROJECT
The proposed project includes construction of a residential structure on a previously
rough graded and city approved parcel recently split from a larger parcel.
SITE LOCATION
The site resides at 1284 Pine Avenue in the City of Carlsbad. A Vicinity map is attached
herein as Figure 1 on the following page.
DESCRIPTION OF WATERSHED
The existing property (parcel 2 of parcel map 21580) is approximately 0.1741 acres,
currently an undeveloped lot, however recently graded. There is currently no specific
drainage system, and runoff flows westward as sheet flow and is discharged existing
paver driveway and swale exiting onto Pine Avenue to the south
Proposed development consists of a residential structure with permeable paver sidewalks
and landscaping on the remainder of the site. Proposed drainage consists of roof drains
that are collected and disposed into landscape area at the front or eastern end of the
building; where it is allowed to infiltrate. Area drains are proposed
There is no existing run on and there will be no post development run on of storm waters.
Referring to the County of San Diego Hydrology Manual the following parameters were
obtained regarding the site:
100 yr. - 6 hour Rainfall Event: 2.3 inches (adjusted) 100 yr. -24 hour Rainfall Event 4.1
inches
Hydrologic Soil Group: B (based upon hydrology manual plates)
Runoff Coefficient: C=0.25 for areas with 0% impervious cover and C=0.45 for areas of
partial impervious cover (table 3-1) ---- two basin types analyzed in this study.
11
0
C
DO
VICINITY MAP
NOT TO SCALE: THOMAS GUIDE COCA. PAGE 1106 F-5
METHODOLOGY
Utilizing the rational method as outlined in the County of San Diego Hydrology Manual,
the 100 year-6 hour storm event peak flows were calculated to drainage basin peak flows
and corresponding drainage areas. A summary of the calculated peak flows follows in the
chart titled Calculation Summary. In addition, on-site drainage pipes were sized utilizing
Manning's equation. Inlet grates were analyzed using the weir and orifice equations.
Calculations and corresponding documentation is provided in Appendix B.
SUMMARY
The 100 year peak flows for the parcel for the year storm indicated was calculated and is
presented below for design purposes. Calculated 100 year peak flow, 0, in tables is cubic
feet per second, CFS.
CALCULATION SUMMARY
Basin Dev Qi 00 Und Qi 00 Dev Ic Und Tc
Parcel 0.204 cfs 0.153cfs 17.4 min. 12.6 mm.
The parcel saw a slight increase of .05 cfs in the post development scenario. This is a
negligible amount being added to the Pine Avenue stormwater collection swale on the
north side of the Street.
Conclusion
It is our professional opinion that the additional flow of 0.05 cfs will have a negligible
impact on the existing public storm drain system.
APPENDIX A
HYDROLOGY BASIN MAP(S)
--
N
F
LECEND
NOTE: TYPE "8" SO LS TYP. 0' 10' 40'
I 20'
SCALE: 1" 20'
PROJECT DATA:
DRAINAGE BASIN DATA:
BASIN I.D. % IMP "C"
(: D 0% 0.25
PROJECT ID. 829 SOUTH PACIFIC
APN NO. : 150-356-18
ADDRESS: 829 SOUTH PACIFIC STREET
OCEANSIDE CA 92054
AREA
0.174 AC
BASIN LABEL
EXISTING CONDITION iIYDROLOGY A
F -- ------ - -------- -- ----- ------- ----, ---- ---- - - - --Ti - -- ---------- --- --- ------- --------- --
11263 TW/10797 TF 11397 TW/11063 IF,
11330 TW/10797 IF 11333 T\'(N)
11263 lW(S) 11397 TW(S)
11263 TW(N)\ 10797 T,F DRAIN GUlLET r10900 IL
11263 lW(S) 10863 1F(N)
11063 IF(S)
/
'
ry
MAX
WALL, EXISTING
Ln
E
WALL DGE'OT MIA FOOTING
In 7 19'
--- . ----------------6O RIGHT OF 'V
TIO
PVC PIPE
777
7 /
CENTERLINE
EXISTING
TERMER (APP,) I 41O%4"
/
- 2329 --
EX. 8' SE
LEGEND
NOTE: TYPE "8" SOI LS TYP. ro 0' 10' DRAINAGE BASIN BOUNDARY PROJECT DATA:
20
SCALE: 1" 20' PROPERTY LINE
PROJECT ID. 829 SOUTH PACIFIC
ARN NO. :150-356-18
ADDRESS: 829 SOUTH PACIFIC STREET
OCEANSIDE CA 92054
DRAINAGE BASIN DATA:
BASIN I.D. % IMP "C" AREA
40.6% 0.45 0.174 AC
220 L.F. PLOW PATH & DIRECTION
BASIN LABEL DEVELOPED CON D I TI ON HYD R OLOGY MA P
APPENDIX B
CALCULATIONS AND FIGURES
RATIONAL METHOD PEAK FLOW CALCULATIONS
Given the geographic coordinates of 33.162043° and -117.339504°, we determine:
From the San Diego County Hydrology Manual "SOILS HYDROLOGIC GROUP
MAP", the soils are identified as type "B" soils.
From the San Diego County Hydrology Manual 'Table 3-1---RUNOFF
COEFFICIENTS FOR URBAN AREAS", the runoff coefficients were determined to
be C=0.25 for areas with 0% impervious cover and C=0.45 for areas under
developed conditions---the two basin types analyzed in this study.
From the San Diego County Hydrology Manual "FIGURE 3.1 --- INTENSITY
DURATION DESIGN CHART TEMPLATE", the Intensity values are established
for the 100 year storm.
From the San Diego County Hydrology Manual Rainfall Isopluvial charts "100
YEAR RAINFALL EVENT 6-HOURS AND 24 HOURS", the rainfall events were
established as: 100 year--6 hour precipitation is (P100-6) = 2.6 inches and the 100
year-24 hour precipitation is (P100-24) = 4.1 inches. Per SD County, P100-6
was adjusted to 2.3 Inches and used as the basis for this study.
Utilizing the Rational Equation Q = CIA, the following flow rates on the next page can be
calculated.
Hydraulic Calculations/Documentation
1) Yard Drains (along drainage pipe)
Calculation following indicate that a 4" drain pipe flowing full at 2% will carry 0.29 cfs.
That is more that the developed condition for the entire project, so it will be assumed
that the 4" pipe is adequate.
A
A
ADcA&L I¼floD t4oLOi/•
hr too ~jm =
!,!he- c[co 4,
!c1uAPtr t;. L.- i. —1 3 M110.
iiILfiom_i AT z"/t
L Z'Zo
A9' 1AØ2
1:
San Diego County Hydrology Manual Section: 3
Date: June 2003 Page: 6 of 26
Table 3-1
RUNOFF COEFFICIENTS FOR URBAN AREAS
- Land Use I Runoff Coefficient "C"
Soil Type
Elements I %
Permanent Open Space 0 0.20 0.25%/ 0.30 0.35
Residential, 1.0 DU/A or less 10 0.27 0.32 0.36 0.41
Residential, 2.0 DU/A or less 20 0.34 0.38 0.42 0.46
Residential, 2.9 DU/A or less 25 0.38 0.41 0.45 0.49
Residential, 4.3 DU/A or less 30 0.41 0.45 0.48 0.52
Residential, 7.3 DU/A or less 40 0.48 0.51 0.54 0.57
Residential, 10.9 DU/A or less 45 0.52 0.54 0.57 0.60
Residential, 14.5 DU/A or less 50 0.55 0.58 0.60 0.63
Residential, 24.0 DU/A or less 65 0.66 0.67 0.69 0.71
Residential, 43.0 DU/A or less 80 0.76 0.77 0.78 0.79
Neighborhood Commercial 80 0.76 0.77 0.78 0.79
General Commercial 85 0.80 0.80 0.81 0.82
Office Professional/Commercial 90 0.83 0.84 0.84 0.85
Limited Industrial 90 0.83 0.84 0.84 0.85
General Industrial 95 0.87 0.87 0.87 0.87
NRCS Elements
Undisturbed Natural Terrain (Natural)
Low Density Residential (LDR)
Low Density Residential (LDR)
Low Density Residential (LDR)
Medium Density Residential (MDR)
Medium Density Residential (MDR)
Medium Density Residential (MDR)
Medium Density Residential (MDR)
High Density Residential (HDR)
High Density Residential (HDR)
Commercial/Industrial (N. Corn)
Commercial/Industrial (G. Corn)
Commercial/Industrial (O.P. Corn)
Commercial/Industrial (Limited I.)
The values associated with 0% impervious may be used for direct calculation of the runoff coefficient as described in Section 3.1.2 (representing the pervious runoff
coefficient, Cp, for the soil type), or for areas that will remain undisturbed in perpetuity. Justification must be given that the area will remain natural forever (e.g., the area
is located in Cleveland National Forest).
DU/A = dwelling units per acre
NRCS = National Resources Conservation Service
3-6
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MANNING'S EQUATION FOR PIPE F
Project: 11284 PINE AVENUE
By: WCH
Chk. By:
jLocation: 11284 PINE AVENUE, CARLSBAD
Date: 11/5/2019
Date: mdo version 12.8.00
Clear Data
0 Entry Cells
INPUT
Mannings Formula
dl
Q=(1 .486/n)ARh S1
R=A/P
A=cross sectional area
P=wetted perimeter
S=slope of channel
n=Manning's roughness coefficient
lSolution to M
Wetted Hydraulic
Area,ft2 Perimeter, ft Radius, ft velocity
I 0.09 1.05 0.08 I 3.34
D= winches
d= 41inches
n= 0.01 n= coeft
0= 0.0 degrees
S=[ 0.02] slope in/in
V=(1 .49/n) RhS1
Q=V x A
n-values
)w, cfs PVC
PE (<9"dia)
0.01
0.015 0.29 1
PE (>12"dia)
PE(9-1 2"dia)
0.02
0.017
CMP 0.025
ADS N12 0.012
HCMP 0.023
Conc 0.013
APPENDIX C
WATERSHED INFORMATION
County of San Diego
Orange- Hydrology Manual 33*3(Y— ___ County
Riverside County
61
\, Rainfall Isopluvials
33'15'
100 Year Rainfall Event 24 Hours
OCEANSIDE
—
-,
I ID ---.-.---------
IsopIuvial (inches)
. -
°
61 -o s
-- C) ENONI AS -.
3300 -- / _________ 3OO C) SOLANABEACF
-
/. ?( y SE) OE)NTY 50 - ----- -
Q DEL MA
C)
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CD
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di ANTE
ASU 1.3
-'
______ — ____________ _____________________ - 32o45'
------ -.i---------
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.
.----
-.--- __________- - --------- 2 45
A DPW SID
IMPERIAL ACH - -
MeXfl
323O' S 32'30'
Ell -
3 0 3Mjles
County of San Diego
Orange __________j__________ ________ __________ ____
Hydrology Manual
County I
Riverside County
Rainfall Isopluvials
33 15
100 Year Rainfall Event 6 Hours
3315
_
...
25
OCEANS!DE
....... ....
Isopluvial (inches)
Der ..:
CARLSEAD ...
;••,•
Cl ENCIN ._. / - , . ••..--. .. ,.•,
3300 -. _ ____________ ______ S3 *00' 0 SOLENA BEACI ________ / P(W j so coums
____________
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CD .....-
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32 45 245' ,•-.•._.•. -
- .. . . - ORON •" .' - ... ------- co
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DP Sa1GIS GIS
its
IMPERCLACF . . , .,i ... ..-------
-
cos
M e X
3230 3230 S ________________________
Ell
__________________________
b 3 0 3MiIes
County of San Diego
Orange
____ _______ __________ ____________ ____ ______
Hydrology Manual --t. County l~
- -
Riverside County -
-- fl
- . Soil Hydrologic Groups
3315-- . ___________
-33 d
V, ffial . ,.
-
I gpnd
F- I _..
-
tt - r ISoil Groups
rn- Elilili Group
Al Group -0 - . -- ) ,.• - -_ II'j• . . 'i Group C - LJ
C) - ENCIN -' I •
- - :-<- r , ..'i & Group D
-
V
Undetermined ___________ _______________
. - _____ Data Unavailable -
33 01 SONABF ..
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IMPERIAL
M e x C 0
3230 3230
3O3Mes
SOLANA BEAC
-
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CARLS BAD
ENCINITA
330 00'
OCEANSID