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C O R N IE R S T O N IE
IE N ((^1~N IE IE R II N G
CONSULTING CIVIL ENGINEERS & LAND SURVEYORS
HYDROLOGY STUDY
FOR
NORTH COUNTY GMC
CityofCarlsbad
APN #211-060-03
October 11,2005
PREPARED BY: Aaron McWilliams, EIT 113493
CHECKED BY: Derrill G. Whitten, PE 51930
CORNERSTONE ENGINEERING, INC
Derrill G. Whitten, PES 1930 -7 / _
CEI Job #817-01-00
2505 'M' Street
Bakersfield, CA '=3:?01
Ter RH',325,947.1. c^v ,,,fii -5;)2.0-':>c
www.comerstoneeng.com
620 Mission Avenue
Oce.3nside, CA 92054
j.7?.2,:3495 - Fax 760.722,;349G
North County GMC
Hydrology Study
Page i
SHEET INDEX
DISCUSSION 1.2
RATIONAL METHOD STUDY 3.9
Maximum Overland Flow Length and Initial Time of Concentration (Table 3-2) 3
Rational Fomiula - Overland Time of Flow Nomagraph (Figure 3-3) 4
Intensity-Duration Design Chart (Figure 3-1) 5
Runoff CoefTicients for Urban Areas (Table 3-1) 6
FEMA Flood Insurance Rate Map 06073 C0764 F (FIRM) 7
Sample Calculations 8.9
Drainage Calculation Summary Table 10
STORM DRAIN SYSTEM ANALYSIS 11-19
STORM DRAIN LAYOUT AND DRAINAGE SUB AREAS 20
8170100 - Hydrology Study 070505.doc
North County GMC
Hydrology Study
Page 1 of2
PURPOSE
The North County GMC Dealership is an existing automobile dealership located along
Paseo Del Norte, approximately 0.2 miles south of the intersection of Paseo Del Norte
and Cannon Road. A remodeling project will be carried out to increase on-site services.
The site occupies nearly 3.40 acres in Carlsbad, Califomia. The purpose of this study is
to determine the peak flow rate for a 10-year rain event under remodeled conditions. The
results of this study will be used to design a storm drain system which will mitigate the
impact of increased flows on the site, proposed buildings, and adjacent properties.
DESCRIPTION OF EXISTING WATERSHED
The North County GMC Dealership occupies nearly 3.40 acres. The general site vicinity
can be found on FEMA Flood Insurance Rate Map Community-Panel Number:
06073C0764F. This map shows that the site is located in non-flood zone X. This
signifies that the project site is outside the SOO-year floodplain. The 10-year, 6-hour
rainfall depth in this area is 1.6S inches, while the 10-year, 24-hour rainfall depth is 3.00
inches. The 3.40 acre site is currently host to an automobile dealership with a showroom,
offices, and parking lot. Runoff generally drains from east to west across the site. There
is an existing on-site collection system of swales, concrete channels and storm sewer
which discharges into an existing CalTrans drainage canal. The CalTrans canal is located
along the westem boundary of the site.
METHODOLOGY
The North County GMC Dealership will be graded to have three drainage sub-areas. The
sub-areas are delineated as shown on the Drainage Sub-Areas Map provided. Sub-areas
A, B, and C will direct the surface water mnoff by use of gutters and swales to each of
three drop-grate type catch basins. Each of these sub-areas will also have an initial sub-
area (e.g. Ai). The mnoff fi-om the three on-site drop-grate catch basins will be piped to
the existing CalTrans drainage channel located between Interstate S and the west
boundary of the site.
A mnoff coefficient was developed based on the fi-action of pervious and impervious
areas to the total area. The mnoff coefficient equation in the SDCHM, Sec. 3, Pg. 5, and
the various mnoff coefficient values in Table 3-1 were used to calculate the developed
mnoff coefficient for each sub-area. The percentage of impervious area was multiplied
by 0.90, while the percentage of pervious area was multiplied by 0.80 as specified for a
General Commercial development.
For analysis ofthe developed site, the initial time of concentration, Tj, was obtained fi-om
the San Diego County Hydrology Manual, Table 3-2. The maximum overland length for
the initial sub-area is dictated by Table 3-2. The remaining overland travel distance,
mnoff coefficient, and slope were used with the equation found in Figure 3-3 to
determine the travel time of concentration, Tt. The total time of concentration for each
sub-area is the sum of the initial time of concentration and the travel time of
concentration. The SDCHM was used in accordance with the City of Carlsbad
Engineering Standards, Vol. 1, Ch. 5.2.C. The Tc fi-om each sub-area was used with the
equation in Figure 3-2 of the SDCHM to obtain an intensity, I (I = 7.44*P6*D'° ^''^ in
inches/hour). The ?6 signifies the 10-year, 6-hour rainfall depth. The requires
adjustment if it is not between 45% and 65% of the 10-year, 24-hour rainfall depth.
8170100 - Hydrology Study 070805.doc
North County GMC
Hydrology Study
Page 2 of2
The flow to the catch basin in each sub-area was calculated using the equation: Q =
C*I*A. The Drainage Calculation summary in the Calculations section of this report lists
all data and equations used in the analysis, as well as sample calculations displaying the
process.
STORM DRAIN DESIGN AND ANALYSIS
The storm drain system for the North County GMC Dealership was designed using
Hydraflow Storm Sewers 2003. The storm drain model layout is shown on the
Hydraflow Plan View sheet in the Rational Method Study section of this report. Two
separate models were used to represent the storm drain system. The system was designed
for a 10-year storm.
The rational method was used to calculate the flow generated fi-om each sub-area to its
respective storm drain inlet. The storm drain for Sub-areas A and B will be made of 18-
inch HDPE pipe and will cormect to a dissipater before emptying into the existing
CalTrans drainage channel. The catch basin in Sub-area C will tie directly into a
dissipater to empty into the chaimel. The cormection was modeled as 5 linear feet of 18"
concrete pipe. The values used to calculate the flow generated by each sub-area are
shown in the Drainage Calculation Summary Table. All storm drain inlets on site are in a
sag condition, so all flow going to a particular inlet will be captured with no carryover
flow going to another inlet.
The 10-year rainfall event flow values obtained fi-om the sub-area mnoff analysis were
entered into Hydraflow to analyze the storm drain system. The program computed the
minor losses due to bends, changes in slope and velocity, and material characteristics.
The pipe materials used in this application were HDPE and concrete, which have
Maiming's numbers of 0.011 and 0.013, respectively. Inlet analyses, including captured
and bypassed flows, storm drain calculations, and Hydraulic Grade Line computations are
shown in the calculations section. The Hydraflow Summary is also shown.
SUMMARY
The Rational Method was used to determine the 10-year post-development peak mnoff
flows for the 3.40 acre North County GMC Dealership in Carlsbad. It was determined
that mnoff developed on site will drain to the existing canal miming along the west
boundary ofthe site. A peak flow of 2.50 cfs will be piped into the canal fi-om the system
containing Sub-area C and 5.29 cfs will be piped into the canal fi-om the system
containing Sub-areas A and B.
REFERENCES
City of Carlsbad Engineering Standards, 2004
FEMA, Flood Insurance Rate Map; Map Number 06073 C0764 F, 1997
Grading Plans by Comerstone Engineering hic, 2005
San Diego County Hydrology Manual, 2003
8170100 - Hydrology Study 070805.doc
San Diego County Hydrology Manual
Date: June 2003
Section:
Page:
3
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 Tj 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)
Element"" DU/
Acre
.5% 1% 2% 3% 5% 10% Element"" DU/
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 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 5.4 100 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
O.P./Com 50 4.2 60 3.7 70 3.1 80 2.9 90 2.6 100 2.2
Limited 1. 50 4.2 60 3.7 70 3.1 80 2.9 90 2.6 100 2.2
General 1. 50 3.7 60 3.2 70 2.7 80 2.6 90 2.3 100 1.9
'•'See Table 3-1 for more detailed description
3-12
100
LiJ
o z < h-CO
Q
UJ
CO
CC Z) o o ce
LiJ
I-
i
EXAMPLE:
Given: Watercourse Distance (D) = 70 Feet
Slope (s)=1.3%
Runoff Coefficient (C) = 0.41
Overland Flow Time (T) = 9.5 Minutes
SOURCE; Airport Drainage, Federal Aviation Administration, 1965
1.8 (1.1-C) VD
FIGURE
Rational Formula - Overland Time of Flow Nomograph
Application Fonn:
(a) Selected frequency
(b) Pe = in., P24 =
(c) Adjusted Pg'2> =
Dlractions for Application:
(1) From precipitation maps determine 6 hr and 24 hr amounts
for the selected frequency. These maps are included In the
County Hydrokigy Manual (10,50, and 100 yr maps included
in the Design and Procedure Manual).
(2) Adjust 6 hr precipitation (if necessary) so lhat It is within
the range of 45% to 65% of the 24 hr precipitation (nol
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.
. year
P 24
%<2)
mm.
in./hr.
Note; This chart replaces the Intensily-Duration-Frequency
cun/es used since 1965.
1.5
I
2.5
I
3.S
3.95 5 27
3.18 4.24
2.53 3.37
1 95 2.59
1.62 2.15
1.40 1 87
1.24 1 66
103 1 38
0 90 1.19
0 80 106
061 0.82
051 0.68
0 44 0.59
0 39 0 52
0 33 0.43
0 28 0 38
0-2S 0.33
4.5
I
5.5
6 59 7.90 922
5.30 6.36 7 42
4.21 5,05 5 90
3.24 3 89 4 54
2.69 3.23 3 77
2.33 2,80 3 27
2.07 2 49 2 90
1.72 2 07 2 41
1,79 2 09
1 59 1 86
1.23 143
1 02 1 19
0.73 0 88 1 03
0 65 0.78 0 91
0.54 0 65 0 76
0 47 0 56 0 66
0.42 0 50 0 58
1 49
1 33
1.02
0.85
10.54
8.48
6.74
5 19
431
3 73
332
2 76
2 39
2 12
1 63
1.36
1.18
1 04
0.87
0 75
0 67
11.86
9.54
7.58
584
4.85
4.20
3.73
3.10
2.69
239
1.84
1 53
1 32
1.18
098
0.85
0.75
13.17
10.60
8.42
6.49
5.39
4.67
4.15
3.45
2.98
2.65
204
1.70
1 47
1.31
1 08
0.94
0.84
1449 1581
11.66 12.72
9.27 10.11
7 13
5.93
5.13
4.56
3 79
3.28
2 92
2.25
1.87
1.62
t 44
1.19
1 03
0.92
778
6.46
5.60
4.98
4 13
3.58
3 IB
2.45
2.04
1.76
1.57
1 30
1.13
1.00
Intensity-Duration Design Chart - Template
FIGURE
3-1
San Diego County Hydrology Manual
Date: June 2003 Section:
Page: 3
6 of 26
Table 3-1
RUNOFF COEFFICIENTS FOR URBAN AREAS
Land Use Runoff Coefficient "C"
Soil Type
NRCS Elements County Elements % IMPER. A B C D
Undisturbed Natural Terrain (Natural) Permanent Open Space 0* 0.20 0.25 0.30 0.35
Low Density Residential (LDR) Residential, 1.0 DU/A or less 10 0.27 0.32 0.36 .0.41
Low Density Residential (LDR) Residential, 2.0 DU/A or less 20 0.34 0.38 0.42 0.46
Low Density Residential (LDR) Residential, 2.9 DU/A or less 25 0.38 0.41 0.45 0.49
Medium Density Residential (MDR) Residential, 4.3 DU/A or less 30 0.41 0.45 0.48 0.52
Medium Density Residential (MDR) Residential, 7.3 DU/A or less 40 0.48 0.51 0.54 0.57
Medium Density Residential (MDR) Residential, 10.9 DU/A or less 45 0.52 0.54 0.57 0.60
Medium Density Residential (MDR) Residential, 14.5 DU/A or less 50 0.55 0.58 0.60 0.63
High Density Residential (HDR) Residential, 24.0 DU/A or less 65 0.66 0.67 0.69 0.71
High Density Residential (HDR) Residential, 43.0 DU/A or less 80 0.76 0.77 0.78 0.79
Commercial/Industrial (N. Com) Neighborhood Commercial 80 0.76 0.77 0.78 0.79
Commercial/Industrial (G. Com) General Commercial 85 0.80 0.80 0.81 0.82
Commercial/Industrial (O.P. Com) Office Professional/Commercial 90 0.83 0.84 0.84 0.85
Commercial/Industrial (Limited I.) Limited Industrial 90 0.83 0.84 0.84 0.85
0.87 Commercial/Industrial (General 1.) General Industrial 95 0.87 0.87 0.87
0.85
0.87
. - - -r •—J V4.,»,vt ^c^xvuiciiuii UIC luiiuii i.uciin.iciu US ucscrioeu m secuon (representmg the pervious runoff
coetticient, 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 m Cleveland National Forest). ^""^
DU/A = dwelling units per acre
NRCS = National Resources Conservation Service
3-6
APPROXIMATE SCALE IN FEET
500 0 500
mum rm mmm PROSIIW)
ZONE X
FIRM
FLOOO INSURANCE RATE MAP
SAN DIEGO COUNTY
CALIFORNIA AND
I INCORPORATED AREAS
*:.\r£-
CITY OF CARLSBAD
060285
NOTE: MAP AREA SHC
TOWNSHIP 12 SOUTH]
ma. 764 OF 2375
BEE MAP INDEX FOH PANELS NOT PRINTED)
COWMNS:
COMMUNmr
CMuaMLOTv or <«• am cam. i—rn»uui» M
MHP NUMBER
06073C0764 F
EFFECnVE DATE-
JUNE 19,1997
[ Federal Emergency Managonmi Agency j
JOB.
CE>
Corimerstoinie Einig'iinieeiriiimg' Iinic.
2505 M Street Bakersfield, CA 93301 SHEET NO
(661) 325-9474
www.cornerstoneeng.com
0F_
CALCULATED BY.
CHECKED BY
SCALE
DATE.
DATE.
I
"72 = l6.lo2,A/' ,w
JOB. Come'irstone Eng-ineerilinigr Knc
2505 M Slreet Bakersfield, CA 93301 SHEET NO
(661) 325-9474
www.cornerstoneeng.com CALCUUTED BY.
CHECKED BY
SCALE
OF '•'^
DATF V' i ' iy'-
DATE
!S I,
Soli. S'^o^- t-^r'K (\, ;
Ft
A Acc A, (he)
Drainage Calculation Summary Table
Total
(ac)
Impervious
(ac)
Pervious
(ac)
C
Impervious
C
Pervious
C
Tolal
LM
Max Inllial Lenglh
(ft)
L
Overland Dislance
(ft)
H
Heighl
(ft)
s
Slope
%
Tl (Table 3-2)
Initial Time of
Concentration (min)
Tt (Figure 3-3)
Travel Time of
Concentration (min)
Tc (Ti + Tc)
Overall Time of
1 (10-yr)
Intensity
(in/hr)
Q-10
Flew
A
B
C
1.19
0.96
1.23
1.00
0.87
1.13
0.1872
0.0947
0.1003
0.9
0.9
0.9
0.8
0.8
0.8
o!884
0.890
0.892
60
60
50
269
262
313
3.18
2.95
1.29
1.1822
1.1260
0.4121
4.1000
4.1000
4.7000
6.0232
5.8764
8.9078
10.1232
9.9764
13.6078
2.7582
2.7843
2.2791
2.90
2.39
2.50
Hydraflow Plan View
Outfall
Project file: 8170100 Subarea A-B lOyr.stm
\Sub-area A
, Sub-area B
No. Lines: 2 10-11-2005
Hydraflow Storm Sewers 2003
3!orrffiewer Inventory l??po" Page 1
Line
No.
Alignment
Dnstr
line
No.
End
1
Line
length
(ft)
66.5
173.5
Defl
angle
(deg)
-22.5
78.5
June
type
DrGrl
DrGrt
Flow Data
Known
Q
(cfs)
2.90
2.39
Dmg
area
(ac)
0.00
0.00
Runoff
coeff
(C)
0.00
0.00
Inlet
time
(m!n)
0.0
0.0
Physical Data
Invert
El Dn
(ft)
61.14
61.37
Line
slope
(%)
0.35
0.65
Invert
El Up
(ft)
61.37
62.50
Line
size
(In)
18
18
Line
type
Cir
Cir
Project File: 8170100 Subarea A-B lOyr.stm
N
value
(n)
0.011
0.011
J-loss
coeff
(K)
1.50
1.00
inlet/
Rim El
(ft)
63.87
64.50
Line ID
Sub-area A
Sub-area B
Number of lines: 2 Date: 10-11-2005
Hydraflow Storm Sewers 2003
storm Sewer Summary Report Page 1
Line
No.
Line ID
Sub-area A
Sub-area B
Flow
rate
(cfs)
5.29
2.39
Line
size
(in)
18 c
18 c
Line
length
(ft)
66.5
173.5
Invert
EL Dn
(ft)
61.14
61.37
Invert
EL Up
(ft)
61.37
62.50
Line
slope
(•/.)
0.346
0.651
HGL
down
(ft)
62.24
62.61
HGL
up
(ft)
62.61
63.35
Minor
loss
(ft)
0.43
0.21
Dns
line
No.
End
1
Project File: 8170100 Subarea A-B lOyr.stm Number of lines: 2 Run Date: 10-11-2005
NOTES: c = circular; e = elliptical; b = box; Return period = 10 Yrs.; * Indicates surcharge condition.
Hydraflow Storm Sewers 2003
- iinit moW Page 1
Line
No
Inlet ID
Sub-area A
Sub-area B
Q =
CIA
(cfs)
2.90*
2.39*
Q
carry
(cfs)
0.00
0.00
Q
capt
(cfs)
Q
byp
(cfs)
2.90
2.39
0.00
0.00
June
type
DrGrt
DrGrt
Curb Inlet
Ht
(in)
0.0
0.0
L
(ft)
0.00
0.00
Grate Inlet
area
(sqft)
4.00
4.00
L
(ft)
2.00
2.00
W
(ft)
2.00
2.00
Gutter
So
(ftm)
Sag
Sag
W
(ft)
4.00
4.00
Sw
(ft/ft)
0.030
0.030
Sx
(ft/ft)
0.030
0.030
Project File: 8170100 Subarea A-B lOyr.stm l-D-F File: Tehachpi lOyear kchm method.lDF
0.000
0.000
depth
(ft)
0.30
0.26
spread
(ft)
23.73
21.34
Inlet
depth
(ft)
0.30
0.26
spread
(ft)
23.73
21.34
Number of lines: 2
Dep
(in)
0.00
0.00
Byp
line
No
Off
Off
Run Dale: 10-11-2005
NOTES: Inlet N-Values= 0.016 ; Intensity = 9.13/(Inlet time+ 0.10)0.63; Retum period = 10 Yrs.; * Indicates Known Q added
Hydraflow Storm Sewers 2003
HySraiHic drad^neT omputations Page 1
Line Size
(in)
18
18
(cfs)
5.29
2.39
Downstream
Invert
elev
(ft)
61.14
61.37
HGL
elev
(ft)
62.24
62.61
Depth
(ft)
1.10
1.24
Area
(sqft)
1.39
1.56
Vel
(ft/s)
3.81
1.53
Vel
head
(ft)
0.23
0.04
EGL
elev
(ft)
62.47
62.64
Sf
(%)
n/a
n/a
Len
(ft)
66.5
174
Upstream
Invert
elev
(ft)
61.37
62.50
HGL
elev
(ft)
62.61 i
63.35i
Depth
(ft)
0.99
0.59
Area
(sqft)
1.23
0.65
Vel
(ft/s)
4.29
3.70
Vel
head
(ft)
0.29
0.21
Project File: 8170100 Subarea A-B lOyr.stm
EGL
elev
(ft)
62.891 n/a
Sf
(%)
Check
Ave
Sf
(%)
63.561 n/a
n/a 0.142
Enrgy
loss
(ft)
JL
coeff
(K)
n/a
Number of lines: 2
0.705
1.50
1.00
Minor
loss
(ft)
n/a
n/a
Run Date: 10-11-2005
NOTES: * Nomial depth assumed., ** Critical depth assumed., i Under inlet conlrol.
Hydraflow Storm Sewers 2003
Hydraflow Plan View
Outfall
Project file: 8170100 Subarea 0 lOyr.stm No. Lines: 1 10-11-2005
Hydraflow Storm Sewers 2003
" SfSrrffSewer Inventory RepoT Page 1
Line
No.
Alignment
Dnstr
line
No.
End
Line
tength
(ft)
5.0
Defl
angle
(deg)
-23.6
June
type
DrGrl
Flow Data
Known
Q
(cfs)
2.50
Drng
area
(ac)
0.00
Runoff
coeff
(C)
0.00
Inlet
time
(min)
0.0
Physical Data
Invert
El Dn
(ft)
60.14
Line
slope
(%)
17.20
invert
El Up
(ft)
61.00
Line
size
(in)
18
Project File: 8170100 Subarea C lOyr.stm
Line
type
Cir
N
value
(n)
0.013
J-loss
coeff
(K)
1.00
Inlet/
Rim El
(ft)
62.50
Line ID
Sub-area C
Number of lines: 1 Date: 10-11-2005
Hydraflow Storm Sewers 2003
storm Sewer Summary Report Page 1
Line
No.
Line ID
Sub-area C
Flow
rate
(cfs)
2.50
Line
size
(in)
18 c
Line
length
(ft)
5.0
Invert
EL Dn
(ft)
60.14
Invert
EL Up
(ft)
61.00
Line
slope
(%)
17.200
HGL
down
(ft)
60.92
HGL
up
(ft)
61.87
Minor
loss
(ft)
0.22
Dns
line
No.
End
Project File: 8170100 Subarea C lOyr.stm Number of lines: 1 Run Date: 10-11-2005
NOTES: c = circular; e = elliptical; b = box; Return period = 10 Yrs.; * Indicates surcharge condition.
Hydraflow Storm Sewers 2003
" Inlet RepoTT
Line
No
Inlet ID
Sub-area C
Q =
CIA
(cfs)
2.50*
Q
carry
(cfs)
0.00
Q
capt
(cfs)
2.50
Q
byp
(cfs)
0.00
June
type
DrGrl
Curb Inlet
Ht
(in)
0.0
L
(ft)
0.00
Grate Inlet
area
(sqft)
4.00
L
(ft)
2.00
W
(ft)
2.00
Gutter
So
(ftm)
Sag
W
(ft)
4.00
Sw
(ftfft)
0.030
Sx
(fttft)
0.030 0.000
depth
(ft)
0.27
spread
(ft)
21.87
Inlet
depth
(ft)
0.27
spread
(ft)
21.87
Dep
(in)
Page 1
Byp
line
No
0.00 Off
Project File: 8170100 Subarea C lOyr.stm l-D-F File: Tehachpi lOyear kchm method.lDF Number of lines: 1 Run Date: 10-11-2005
NOTES: Inlet N-Values = 0.016 ; Intensity = 9.13 / (Inlet time + 0.10) 0.63; Retum period = 10 Yrs.; * Indicates Known Q added
Hydraflow Storm Sewers 2003
HyffrauTc (Srad^ine^omputation? Page 1
Line
(1)
Size
(in)
(2)
18
(cfs)
(3)
2.50
Downstream
Invert
elev
(ft)
(4)
60.14
HGL
elev
(ft)
(5)
60.92
Depth
(ft)
(6)
0.78
Area
(sqft)
(7)
0.93
Vel
(ft/s)
(8)
2.69
Vel
head
(ft)
(9)
0.11
EGL
elev
(ft)
(10)
61.03
Sf
(•/.)
(11)
n/a
Len
(ft)
(12)
5.0
Upstream
Invert
elev
(ft)
(13)
61.00
HGL
elev
(ft)
(14)
61.871
Depth
(ft)
(15)
0.60
Area
(sqft)
(16)
0.67
Vel
(ft/s)
(17)
3.76
Project File: 8170100 Subarea C lOyr.stm
Vel
head
(ft)
(18)
0.22
EGL
elev
(ft)
(19)
62.091
Sf
(%)
(20)
n/a
Check
Ave
Sf
(%)
(21)
n/a
Enrgy
loss
(ft)
(22)
0.840
Number of lines: 1
JL
coeff
(K)
(23)
1.00
Minor
loss
(ft)
(24)
n/a
Run Date: 10-11-2005
NOTES: * Normal depth assumed.. ** Critical depth assumed., i Under inlet control.
Hydraflow Storm Sewers 2003