HomeMy WebLinkAboutParcel Map 30169 Drainage Report June 20060
DRAINAGE REPORT
Parcel Map 30169 (Ynez Road)
Temecula, California
June, 2006
Prepared For:
Vineyard Custom Homes LLC
0
Prepared By:
SV Engineering Consultants
32605 Hwy. 79 South, Suite 200
Temecula, CA 92592
(951)694-4824
•
• TABLE OF CONTENTS
Section
Page
1.0
INTRODUCTION..............................................................................................
1
2.0
HYDROLOGY CRITERIA..............................................................................
2
2.1 Hydrology Criteria......................................................................................
2
2.2 Hydrology Methodology.............................................................................
2
2.3 Explanation of Civil Design Rational Method Software ............................
3
3.0
PROJECT HYDROLOGIC ANALYSIS...........................................................
4
4.0
HYDRAULIC CRITERIA AND METHODOLOGY ........................................
5
5.0
CONCLUSION...................................................................................................
5
APPENDICES
• 1 RCFC&WCD Hydrologic Soils Group Map, Slope Intensity Curves, 100 -yr,
1 -hr Precipitation Maps
3 Rational Method Computer Output: Developed Conditions 100 -Year
EXHIBITS
A Developed Conditions Hydrology Map
ii
• 1.0 INTRODUCTION
This drainage report has been prepared to quantify the proposed storm drainage run-off
for Parcel Map 30169 and to provide sizing of drainage facilities required to convey the
offsite/onsite run-on through the project site. The Project site is approximately 4.5 acres
and is located in Temecula, California on the east side of Ynez Road, opposite Quite
Meadow Road. This project proposes to construct 4 single family lots and a private
roadway (cul-de-sac) to provide access to the lots.
The offsite and onsite area that contributes to the analysis of this site is approximately 6.0
acres. The drainage basin is comprised of hillside undeveloped land with fair to poor
ground cover.
The proposed storm drain improvements consist of brow ditches, earthen swales,
roadway, under sidewalk drain, and curb and gutter. The project site ultimately
discharges onto Ynez Road.
r1
U
• 2.0 HYDROLOGY CRITERIA
•
This section of the report summarizes the hydrology criteria and key elements of the
hydrologic methodology.
2.1 Hydrology Criteria
Table 1 below presents a summary of the hydrology criteria used in the report.
Table 1: Hydrology Criteria
Storm drain improvements:
100 -year, 1 -hour storm.
Land Use:
Vacant Land (hillside)
Runoff Coefficients:
Per Riverside County Flood Control and Water
Conservation District Hydrology Manual.
Hydrologic Soil Group:
Per Riverside County Flood Control and Water
Conservation District Hydrology Manual.
Intensity:
Per Riverside County Flood Control and Water
Conservation District Hydrology Manual.
2.2 Hydrology Methodology
The Rational Method was used to determine the existing and proposed condition
for the 100 -year 1 -hour storm flows for the design of the Project storm drain
improvements. The 100 -year storm flow was used to size the storm drainpipes.
The 1 -hour storm duration was used in the storm drainpipe design as it generally
produces the higher more conservative peak flows. The Civil Design software
package (Riverside Method) was used in the hydrologic analysis of the
improvements. This includes: 1) Rational Method hydrology analysis.
-2-
. 2.3 Explanation of Civil Design Rational Method Software
The Civil Design Rational Method was used to determine the 100 -year storm flow
for the Project. The Rational Method Hydrology Program is a computer-aided
design program where the user develops a node link model of the watershed. The
program has the capability of estimating conduit sizes to convey design storm
discharges, or the user may input specific conduit sizes and open channels. Soil
types used in the model are based on hydrologic soil groups as outlined in the
RCFC & WCD Hydrology Manual. The rainfall intensity distribution and runoff
coefficients utilized by the program can be user-specified to be based on the
RCFC & WCD Hydrology Manual.
Developing independent node link models for each interior watershed and linking
these sub -models together at confluence points creates the node link model. The
program allows up to five streams to confluence at a node. Stream entries must be
made sequentially until all are entered. The program allows consideration of only
• one confluence at a time. The program has the capability of performing
calculations for 11 hydrologic processes. These processes are assigned code
numbers, which appear in the printed output. The code numbers and their
meanings are as follows:
CODE l:
Initial subarea
CODE 2:
Street flow
CODE 3:
Addition of subarea
CODE 4:
Street inlet
CODE 5:
Natural Mountain/Valley
CODE 6:
Pipeflow (program estimated pipe size)
CODE 7:
Pipeflow (user specified pipe size)
CODE 8:
Improved channel
CODE 9:
Irregular channel
CODE 10: User specified input data
CODE 1 l : Confluence of current stream
• CODE 12: Confluence of main stream
-3-
• 3.0 PROJECT HYDROLOGIC ANALYSIS
The existing drainage area is undeveloped with ground cover of native grass, and brush,
with some areas that have been disked. The purpose of this analysis is to determine the
amount of storm water runoff from the site onto Yenz road in its developed condition.
The hydrologic soils group is D for the project site (Appendix 1).
This project proposes to construct 4 single family lots and a private roadway (cul-de-sac)
to provide access to the lots. The proposed storm drain improvements will include curb
and gutter, brow ditches, and an under sidewalk drain.
Runoffs from the Basins are as follows (Exhibit A):
Basin `A': Basin `A' (nodes 100 — 140) flows overland to the south to a proposed brow
ditch which flows west to Ynez Road. Basin `A's' elevations are from 1100 to 1051,
• which is approximately 2.07 acre in area. This basin generates approximately 6.36 cfs in
the 100 -year storm event. This basin discharges to Ynez Road through a proposed under
n
LJ
sidewalk drain.
Basin `B': Basin `B' (nodes 200 — 230) flows overland to the south to the proposed
private access road which flows west to Ynez Road. Basin `B's' elevations are from
1104 to 1056.5, which is approximately 1.30 acre in area. This basin generates
approximately 4.74 cfs in the 100 -year storm event. This basin discharges to Ynez Road
via curb and gutter.
Basin `C': Basin `C' (nodes 300 — 320) flows overland to the west from elevation 1080.5
to elevation 1055.5, which is approximately 2.66 acre in area. This basin generates
approximately 9.27 cfs in the 100 -year storm event. This basin discharges to Ynez Road
via curb and gutter.
M
• Below is a summary of the proposed 100 -year design discharges
Basin
Q cfs
Structure
`A' (node 100 - 140)
6.36
Brow Ditch / Under sidewalk drain
`B' (node 200 - 230)
4.74
Curb and Gutter
`C' (node 300 — 320)
9.27
Curb and Gutter
4.0 Onsite Brow Ditches
The proposed onsite brow ditches are designed to convey 100 -year storm event which
ultimately discharges to Ynez Road via an under sidewalk drain.
Node
Q (cfs)
V (fps)
Depth of Flow
Structure
120-130
4.85
6.65
0.85
Brow Ditch, Std 304 (A)
130-140
6.36
7.35
0.93
Brow Ditch, Std 304 (A)
(See Appendix under nodes 120-140 for calculations)
7.0 CONCLUSION
This drainage report has been prepared to quantify the proposed storm drainage run-off
for the development of Parcel Map 30169; which includes the construction of 4 single
family residential lots. In the 100 -year storm event the project will discharge
approximately 20 cfs onto Ynez Road which will convey the storm water south to an
existing catch basin in Ynez Road. With the proper installation of the drainage devices
and erosion control measures the storm water runoff from the site should not dramatically
affect the downstream conditions.
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- 5 -
0
APPENDIX
0
0
RCFC&WCD HYDROLOGIC SOILS GROUP MAP, SLOPE
INTENSITY CURVES, 100 -YR, 1 -HR PRECIPITATION MAPS
0
U u _u
4
Z
LEGEND HYDROLOGIC SOILS GROUP MAP
SOILS GROUP BOUNDARY
FOR
A SOILS GROUP DESIGNATION
R C F C a W C D TEMECULA
HYDROLOGY ]MANUAL n!66151�
0 FEET 5000
PLATE C-1.60
0
RATIONAL METHOD COMPUTER OUTPUT
DEVELOPED CONDITIONS 100 -YEAR
0
• Riverside County Rational Hydrology Program
CIVILCADD/CIVILDESIGN Engineering So£tware,(c) 1989 - 2004 Version 7.0
Rational Hydrology Study Date: 06/16/06 File:YnezlA.out
------------------------------------------------------------------------
PM 30169 (Ynez Road)
Basin 'A' 100 -year Storm Event
------------------------------------------------------------------------
********* Hydrology Study Control Information **********
English (in -lb) Units used in input data file
------------------------------------------------------------------------
Rational Method Hydrology Program based on
Riverside County Flood Control & Water Conservation District
1978 hydrology manual
Storm event (year) = 100.00 Antecedent Moisture Condition = 3
Standard intensity -duration curves data (Plate D-4.1)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 100.000 to Point/Station 110.000
**** INITIAL AREA EVALUATION ****
For the [ Murrieta,Tmc,Rnch Callorco
] area used.
Top (of initial area) elevation = 1100.000(Ft.)
10 year storm 10 minute intensity =
2.360(In/Hr)
10 year storm 60 minute intensity =
0.880(In/Hr)
Slope = 0.07000 s(percent)= 7.00
100 year storm 10 minute intensity
= 3.480(In/Hr)
100 year storm 60 minute intensity
= 1.300(In/Hr)
•
UNDEVELOPED (fair cover) subarea
Storm event year = 100.0
Decimal fraction soil group A = 0.000
Calculated rainfall intensity data:
Decimal fraction soil group B = 0.000
1 hour intensity = 1.300(In/Hr)
•
Decimal fraction soil group D = 1.000
Slope of intensity duration curve =
0.5500
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 100.000 to Point/Station 110.000
**** INITIAL AREA EVALUATION ****
Initial area flow distance = 100.000(Ft.)
Top (of initial area) elevation = 1100.000(Ft.)
Bottom (of initial area) elevation = 1093.000(Ft.)
Difference in elevation = 7.000(Ft.)
Slope = 0.07000 s(percent)= 7.00
TO = k(0.710)*[(length^3)/(elevation change)]^0.2
Initial area time of concentration = 7.625 min.
Rainfall intensity = 4.043(In/Hr) for a 100.0 year storm
UNDEVELOPED (fair cover) subarea
Runoff Coefficient = 0.880
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
•
Decimal fraction soil group D = 1.000
RI index for soil(AMC 3) = 93.40
• Pervious area fraction = 1.000; Impervious fraction = 0.000
Initial subarea runoff = 0.676(CFS)
Total initial stream area = 0.190(Ac.)
Pervious area fraction = 1.000 -
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 110.000 to Point/Station 120.000
**** NATURAL CHANNEL TIME + SUBAREA FLOW ADDITION ****
Top of natural channel elevation = 1093.000(Ft.)
End of natural channel elevation = 1072.000(Ft.)
Length of natural channel = 260.000(Ft.)
Estimated mean flow rate at midpoint of channel
Natural mountain channel type used
L.A. County flood control district formula for channel velocity:
Velocity = 5.48(q^.33)(slope^.492)
Velocity using mean channel flow = 2.23(Ft/s)
Correction to map slope used on extremely rugged channels with
drops and waterfalls (Plate D-6.2)
Normal channel slope = 0.0808
Corrected/adjusted channel slope = 0.0808
Travel time = 1.95 min. TC = 9.57 min.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 120.000 to Point/Station 130.000
**** IMPROVED CHANNEL TRAVEL TIME ****
Upstream point elevation = 1072.000(Ft.)
Downstream point elevation = 1067.000(Ft.)
Channel length thru subarea = 225.000(Ft.)
Channel base width = 0.000(Ft.)
Slope or 'Z' of left channel bank = 1.000
Slope or 'Z' of right channel bank = 1.000
Estimated mean flow rate at midpoint of channel = 4.622(CFS)
Manning's 'N' = 0.015
Maximum depth of channel = 1.000(Ft.)
Flow(q) thru subarea = 4.622(CFS)
• Depth of flow = 0.839(Ft.), Average velocity = 6.568(Ft/s)
Channel flow top width = 1.678(Ft.)
Adding area flow to channel
•
UNDEVELOPED (fair cover) subarea
Runoff Coefficient = 0.877
Decimal fraction soil group A =
0.000
Decimal fraction soil group B =
0.000
Decimal fraction soil group C =
0.000
Decimal fraction soil group D =
1.000
RI index for soil(AMC 3) = 93.40
Pervious area fraction = 1.000;
Impervious fraction
= 0.000
Rainfall intensity = 3.567(In/Hr)
for a 100.0
year storm
Subarea runoff = 3.691(CFS)
for 1.180(Ac.)
Total runoff = 4.367(CFS)
Total area =
1.370(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 120.000 to Point/Station 130.000
**** IMPROVED CHANNEL TRAVEL TIME ****
Upstream point elevation = 1072.000(Ft.)
Downstream point elevation = 1067.000(Ft.)
Channel length thru subarea = 225.000(Ft.)
Channel base width = 0.000(Ft.)
Slope or 'Z' of left channel bank = 1.000
Slope or 'Z' of right channel bank = 1.000
Estimated mean flow rate at midpoint of channel = 4.622(CFS)
Manning's 'N' = 0.015
Maximum depth of channel = 1.000(Ft.)
Flow(q) thru subarea = 4.622(CFS)
• Depth of flow = 0.839(Ft.), Average velocity = 6.568(Ft/s)
Channel flow top width = 1.678(Ft.)
•
Flow Velocity= 6.57(Ft/s)
Travel time 0.57 min.
Time of concentration = 10.14 min.
Sub -Channel No. 1 Critical depth = 1.047(Ft.)
' Critical flow top width = 2.000(Ft.)
' Critical flow velocity= 4.226(Ft/s)
' Critical flow area = 1.094(Sq.Ft)
Adding area flow to channel
UNDEVELOPED (fair cover) subarea
Runoff Coefficient = 0.876
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
RI index for soil(AMC 3) = 93.40
Pervious area fraction = 1.000; Impervious fraction = 0.000
Rainfall intensity = 3.456(In/Hr) for a 100.0 year storm
Subarea runoff = 0.484(CFS) for 0.160(Ac.)
Total runoff = 4.851(CFS) Total area = 1.530(Ac
Depth of flow = 0.854(Ft.), Average velocity = 6.648(Ft/s)
Sub -Channel No. 1 Critical depth = 1.070(Ft.)
Critical flow top width = 2.000(Ft.)
' Critical flow velocity= 4.253(Ft/s)
' Critical flow area = 1.141(Sq.Ft)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 130.000 to Point/Station 140.000
**** IMPROVED CHANNEL TRAVEL TIME ****
Upstream point elevation = 1067.000(Ft.)
Downstream point elevation = 1051.000(Ft.)
Channel length thru subarea = 660.000(Ft.)
Channel base width = 0.000(Ft.)
Slope or 'Z' of left channel bank = 1.000
Slope or 'Z' of right channel bank = 1.000
Estimated mean flow rate at midpoint of channel =
Manning's 'N' = 0.015
Maximum depth of channel = 1.000(Ft.)
Flow(q) thru subarea = 5.631(CFS)
Depth of flow = 0.889(Ft.), Average velocity =
Channel flow top width = 1.778(Ft.)
Flow Velocity = 7.13(Ft/s)
Travel time = 1.54 min.
Time of concentration = 11.69 min.
5. 631 (CFS)
7.129(Ft/s)
Sub -Channel No. 1 Critical depth = 1.125(Ft.)
' Critical flow top width = 2.000(Ft.)
' Critical flow velocity= 4.505(Ft/s)
' Critical flow area = 1.250(Sq.Ft)
• Adding area flow to channel
UNDEVELOPED (fair cover) subarea
Runoff Coefficient = 0.874
• Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
RI index for soil(AMC 3) = 93.40
Pervious area fraction = 1.000; Impervious fraction = 0.000
Rainfall intensity = 3.197(In/Hr) for a 100.0 year storm
Subarea runoff = 1.509(CFS) for 0.540(Ac.)
Total runoff = 6.360(CFS) Total area = 2.070(Ac
Depth of flow = 0.930(Ft.), Average velocity = 7.350(Ft/s)
Sub -Channel No. 1 Critical depth = 1.180(Ft.)
' Critical flow top width = 2.000(Ft.)
' Critical flow velocity= 4.679(Ft/s)
' Critical flow area = 1.359(Sq.Ft)
End of computations, total study area = 2.07 (Ac.)
The following figures may
be used for a unit hydrograph study of the same area.
Area averaged pervious area fraction(Ap) = 1.000
Area averaged RI index number = 84.0
•
•
Riverside County Rational Hydrology Program
CIVILCADD/CIVILDESIGN Engineering So£tware,(c) 1989 - 2004 Version 7.0
Rational Hydrology Study Date: 06/16/06 File:YnezlB.out
------------------------------------------------------------------------
PM 30169 (Ynez Road)
Basin 'B' 100 -year Storm Event
----------------------------------------------------------
********* Hydrology Study Control Information **********
English (in -16) Units used in input data file
Rational Method Hydrology Program based on
Riverside County Flood Control & Water Conservation District
1978 hydrology manual
Storm event (year) = 100.00 Antecedent Moisture Condition = 3
Standard intensity -duration curves data (Plate D-4.1)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 200.000 to Point/Station 210.000
**** INITIAL AREA EVALUATION ****
For the [ Murrieta,Tmc,Rnch Callorco
] area used.
Top (of initial area) elevation = 1104.000(Ft.)
10 year storm 10 minute intensity =
2.360(In/Hr)
10 year storm 60 minute intensity =
0.880(In/Hr)
Slope = 0.14000 s(percent)= 14.00
100 year storm 10 minute intensity
= 3.480(In/Hr)
100 year storm 60 minute intensity
= 1.300(In/Hr)
•
UNDEVELOPED (fair cover) subarea
Storm event year = 100.0
Decimal fraction soil group A = 0.000
Calculated rainfall intensity data:
Decimal fraction soil group B = 0.000
1 hour intensity = 1.300(In/Hr)
•
Decimal fraction soil group D = 1.000
Slope of intensity duration curve =
0.5500
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 200.000 to Point/Station 210.000
**** INITIAL AREA EVALUATION ****
Initial area flow distance = 100.000(Ft.)
Top (of initial area) elevation = 1104.000(Ft.)
Bottom (of initial area) elevation = 1090.000(Ft.)
Difference in elevation = 14.000(Ft.)
Slope = 0.14000 s(percent)= 14.00
TC = k(0.710)*[(length^3)/(elevation change)]^0.2
Initial area time of concentration = 6.638 min.
Rainfall intensity = 4.363(In/Hr) for a 100.0 year storm
UNDEVELOPED (fair cover) subarea
Runoff Coefficient = 0.881
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
•
Decimal fraction soil group D = 1.000
RI index for soil(AMC 3) = 93.40
• Pervious area fraction = 1.000; Impervious fraction = 0.000
Initial subarea runoff = 0.884(CFS)
Total initial stream area = 0.230(Ac.)
Pervious area fraction = 1.000
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 210.000 to Point/Station 220.000
**** NATURAL CHANNEL TIME + SUBAREA FLOW ADDITION ****
Top of natural channel elevation = 1090.000(Ft.)
End of natural channel elevation = 1075.400(Ft.)
Length of natural channel = 70.000(Ft.)
Estimated mean flow rate at midpoint of channel = 2.326(CFS)
Natural mountain channel type used
L.A. County flood control district formula for channel velocity:
Velocity = 5.48(q^.33)(slope^.492)
Velocity using mean channel flow = 3.35(Ft/s)
Correction to map slope used on extremely rugged channels with
drops and waterfalls (Plate D-6.2)
Normal channel slope = 0.2086
Corrected/adjusted channel slope = 0.2086
Travel time = 0.35 min. TC = 6.99 min.
Top of street segment elevation = 1075.400(Ft.)
End of street segment elevation = 1056.500(Ft.)
Length of street segment = 420.000(Ft.)
Height of curb above gutter flowline = 4.0(In.)
Width of half street (curb to crown) = 16.000(Ft.)
Distance from crown to crossfall grade break = 14.000(Ft
Slope from gutter to grade break (v/hz) = 0.020
Slope from grade break to crown (v/hz) = 0.020
Street flow is on [1] side(s) of the street
Distance from curb to property line = 9.000(Ft.)
• Slope from curb to property line (v/hz) = 0.020
Gutter width = 2.000(Ft.)
Adding area flow to channel
•
UNDEVELOPED (fair cover) subarea
Runoff Coefficient = 0.880
Decimal fraction soil group A =
0.000
Decimal fraction soil group B =
0.000
Decimal fraction soil group C =
0.000
Decimal fraction soil group D =
1.000
RI index for soil(AMC 3) = 93.40
Pervious area fraction = 1.000;
Impervious fraction = 0.000
Rainfall intensity = 4.242(In/Hr)
for a 100.0 year storm
Subarea runoff = 2.801(CFS)
for 0.750(Ac.)
Total runoff = 3.685(CFS)
Total area = 0.980(Ac.)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station
220.000 to Point/Station 230.000
**** STREET FLOW TRAVEL TIME + SUBAREA
FLOW ADDITION ****
Top of street segment elevation = 1075.400(Ft.)
End of street segment elevation = 1056.500(Ft.)
Length of street segment = 420.000(Ft.)
Height of curb above gutter flowline = 4.0(In.)
Width of half street (curb to crown) = 16.000(Ft.)
Distance from crown to crossfall grade break = 14.000(Ft
Slope from gutter to grade break (v/hz) = 0.020
Slope from grade break to crown (v/hz) = 0.020
Street flow is on [1] side(s) of the street
Distance from curb to property line = 9.000(Ft.)
• Slope from curb to property line (v/hz) = 0.020
Gutter width = 2.000(Ft.)
Area averaged pervious area fraction(Ap) = 0.951
Area averaged RI index number = 81.8
Gutter hike from flowline = 1.000(In.)
•
Manning's N in gutter = 0.0150
Manning's N from gutter to grade break = 0.0150
Manning's N from grade break to crown = 0.0150
Estimated mean flow rate at midpoint of street =
4.249(CFS)
Depth of flow = 0.234(Ft.), Average velocity = 4.453(Ft/s)
Streetflow hydraulics at midpoint of street travel:
Halfstreet flow width = 9.544(Ft.)
Flow velocity = 4.45(Ft/s)
Travel time = 1.57 min. TC = 8.56 min.
Adding area flow to street
SINGLE FAMILY (1 Acre Lot)
Runoff Coefficient = 0.867
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
RI index for soil(AMC 3) = 88.00
Pervious area fraction = 0.800; Impervious fraction
= 0.200
Rainfall intensity = 3.794(ln/Hr) for a 100.0
year storm
Subarea runoff = 1.053(CFS) for 0.320(Ac.)
Total runoff = 4.738(CFS) Total area =
1.300(Ac.
Street flow at end of street = 4.738(CFS)
Half street flow at end of street = 4.738(CFS)
Depth of flow = 0.243(Ft.), Average velocity = 4.572(Ft/s)
Flow width (from curb towards crown)= 9.964(Ft.)
End of computations, total study area = 1.30
(Ac.)
The following figures may
•
be used for a unit hydrograph study of the same area.
Area averaged pervious area fraction(Ap) = 0.951
Area averaged RI index number = 81.8
• Riverside County Rational Hydrology Program
CIVILCADD/CIVILDESIGN Engineering Software,(c) 1989 - 2004 Version 7.0
Rational Hydrology Study Date: 06/16/06 File:YnezlC.out
------------------------------------------------------------------------
PM 30169 (Ynez Road)
Basin 'C' 100 -year Storm Event
------------------------------------------------------------------------
********* Hydrology Study Control Information **********
English (in -1b) Units used in input data file
---------------------------------------------------------------------
Rational Method Hydrology Program based on
Riverside County Flood Control s Water Conservation District
1978 hydrology manual
Storm event (year) = 100.00 Antecedent Moisture Condition = 3
Standard intensity -duration curves data (Plate D-4.1)
For the [ Murrieta,Tmc,Rnch Callorco ] area used.
10 year storm 10 minute intensity = 2.360(In/Hr)
10 year storm 60 minute intensity = 0.880(In/Hr)
100 year storm 10 minute intensity = 3.480(In/Hr)
• 100 year storm 60 minute intensity = 1.300(In/Hr)
Storm event year = 100.0
Calculated rainfall intensity data:
1 hour intensity = 1.300(In/Hr)
Slope of intensity duration curve = 0.5500
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 300.000 to Point/Station 310.000
**** INITIAL AREA EVALUATION ****
Initial area flow distance = 140.000(Ft.)
Top (of initial area) elevation = 1080.500(Ft.)
Bottom (of initial area) elevation = 1072.000(Ft.)
Difference in elevation = 8.500(Ft.)
Slope = 0.06071 s(percent)= 6.07
TC = k(0.480)*[(length^3)/(elevation change)]^0.2
Initial area time of concentration = 6.068 min.
Rainfall intensity = 4.584(In/Hr) for a 100.0 year storm
SINGLE FAMILY (1 Acre Lot)
Runoff Coefficient = 0.873
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
• Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
• RI index for soil(AMC 3) = 88.00
Pervious area fraction = 0.800; Impervious fraction = 0.200
Initial subarea runoff = 2.360(CFS)
Total initial stream area = 0.590(Ac.)
Pervious area fraction = 0.800
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 310.000 to Point/Station 320.000
**** STREET FLOW TRAVEL TIME + SUBAREA FLOW ADDITION ****
Top of street segment elevation = 1072.000(Ft.)
End of street segment elevation = 1055.500(Ft.)
Length of street segment = 560.000(Ft.)
Height of curb above gutter flowline = 4.0(In.)
Width of half street (curb to crown) = 16.000(Ft.)
Distance from crown to crossfall grade break = 14.000(Ft.)
Slope from gutter to grade break (v/hz) = 0.020
Slope from grade break to crown (v/hz) = 0.020
Street flow is on [1] side(s) of the street
Distance from curb to property line = 9.000(Ft.)
Slope from curb to property line (v/hz) = 0.020
Gutter width = 2.000(Ft.)
Gutter hike from flowline = 1.000(In.)
Manning's N in gutter = 0.0150
Manning's N from gutter to grade break = 0.0150
Manning's N from grade break to crown = 0.0150
Estimated mean flow rate at midpoint of street =
5.860(CFS)
• Depth of flow = 0.279(Ft.), Average velocity = 4.1.03(Ft/s)
Streetflow hydraulics at midpoint of street travel:
Halfstreet flow width = 11.768(Ft.)
Flow velocity = 4.10(Ft/s)
Travel time = 2.27 min. TC = 8.34 min.
Adding area flow to street
SINGLE FAMILY (1 Acre Lot)
Runoff Coefficient = 0.868
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
RI index for soil(AMC 3) = 88.00
Pervious area fraction = 0.800; Impervious fraction
= 0.200
Rainfall intensity = 3.848(In/Hr) for a 100.0
year storm
Subarea runoff = 6.910(CFS) for 2.070(Ac.)
Total runoff = 9.270(CFS) Total area =
2.660(Ac.)
Street flow at end of street = 9.270(CFS)
Half street flow at end of street = 9.270(CFS)
Depth of flow = 0.324(Ft.), Average velocity = 4.592(Ft/s)
Flow width (from curb towards crown)= 14.054(Ft.)
End of computations, total study area = 2.66
(Ac.)
The following figures may
be used for a unit hydrograph study of the same area.
Area averaged pervious area fraction(Ap) = 0.800
Area averaged RI index number = 75.0
•
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EXHIBITS
LJ