HomeMy WebLinkAboutMS 857; Bellavista Map 2152; Hydrology Report; 1991-12-01HYDROLOGY AND HYDRAULIC REPORT PRELIMINARY
VICTORIA FERNANDEZ
*REFERENCE DRAWING 328-5AX
PREPARED BY:
PASCO ENGINEERING,
531 NORTH HIGHWAY
INC.
101
SOLANA BEACH, CA 92015
(619) 259-8212
DECEMBER 1991
ENGINEERING DEPT. LIBRARY
City of Carlsbad 2075 Las Palmas Drive Carlsbad, CA 92009-4859 ud
WAYNE PASCd RCE 29511
TABLE OF CONTENTS
I INTRODUCTION .............. 1
I1 DISCUSSION .............. 1
I11 CONCLUSION .............. 1 . 2
IV CALCULATIONS .............. 3 -11
A) HYDROLOGY (100 YEAR) ......... 3 . 5
B) HYDRAULICS .............. 6 . 11
V APPENDIX .............. 12 . 15
VI EXHIBITS .............. 16
Page 1 of 16
I. INTRODUCTION
The subject property, known as APN 206-180-09, is located 225
feet east of Hoover Street on the north side of Adams Street.
The geographic location is N 33'08'45"; W 117'19'42".
The purpose of this report is to analyze the storm water
tributary to the existing and proposed structures as shown on
Exhibit B of this report.
Recommendations will be made based on the information contained
in this report to size storm drain structures that intercept and convey storm flows to their respective discharge points with
little or no change in quantities or velocities from the existing
condition.
11. DISCUSSION
The purpose of the proposed drainage system is to model the
hydraulic characteristics of the existing 12 inch CMP and to
create a safe enviornment for vehciular traffic until full Adams
Street improvements can be accomplished.
The existing 12" CMP that crosses Adams Street at Node 2
analyzed to determine its maximum capacity with the amount of
(Exhibits A and B and Section A-A of the Grading Plan), was
head available. This Qmax was then used to determine the
required size of a "G" Type Catch Basin sufficient to intercept
the same 100 year flow. The depth of available headwater as
proposed is similar to the existing condition.
Along the top of the proposed cut slopes the capacity of the
proposed D-75 Type "B" Brow Ditch for QlOO was checked based on a
on a maximum grade of 50% (2:l).
2% minimum grade. The velocity for QlOO was also checked based
I I I . CONCLUSION
Since the capacity of the 12 inch CMP (Node 2) in its existing condition is 3.8 cfs (inlet control with 1.77 feet of available head, see Page 10) and the amount of available head remains unchanged in the developed condition, the control at the proposed catch basin becomes the size of the opening.
Page 2 of 16
A permineter length of 11.84 feet is required to allow 4.0 cfs
flowing at 0.37 feet deep to be intercepted by a double Type "G"
inlet. (See Pages 6 and 9.)
Utilizing the Type I'G" inlet in this situation will effectively
model the hydraulic characteristics of the existing system, as
well as provide a safe environment for vehicular traffic until
Adams Street can be improved to its ultimate width.
Page 3 of 16
IV CALCULATIONS
A) HYDROLOGY
Page 6 of 16
IV CALCULATIONS
B ) HYDRAULICS
-* OU"" ELEVATION bo* way:
EIw shown on plm
SECTION A-A
CATCH BASIN - TYPE G P= /z '
. ..
Page 12 of 16
APPENDIX
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Page 16 of 16
EXHIBITS