|
=� 340
<br />335 GEl
<br />Es
<br />GRPSS o
<br />—TRPS_
<br />S
<br />�—E
<br />SENSE
<br />0 ASPH. _
<br />■ I ` — —
<br />�50 6 �\ j 6 \
<br />5
<br />RW N 2B (R.
<br />EES
<br />JOHN COURT
<br />H ME OPINE RS
<br />ASSOCIATION
<br />I
<br />SO PUMP AND Ti
<br />DRAIN PIPE TO PI
<br />RUNOFF A T GARAGE
<br />ASPH.
<br />-
<br />CON .
<br />�T__
<br />OGS ON •� ( �S\G
<br />O�NSE ---
<br />T
<br />D
<br />M\A
<br />gr
<br />N
<br />3
<br />.I.
<br />STREET B
<br />DMA 1
<br />Jse F —
<br />DRAIN SYSTEM
<br />0 17 LOW FLOW INLET
<br />• STORMWA TER INLET
<br />WITH SOLID LID
<br />O
<br />DISTRIBUTION
<br />PIPE
<br />IMP 1 ----
<br />LOW FLOW INLET
<br />, r
<br />9 0 M\A
<br />�� 0 3�
<br />i
<br />- /
<br />III ��III SII I�
<br />CONNECT• • - - / PUMP /
<br />DRA IN S Ys TEM
<br />!., .. . _
<br />DMA 2 RUNOFF/•I'
<br />Ia,I=U�,
<br />AN 3B
<br />rum
<br />STORM WATER
<br />TREATMENT
<br />—
<br />—
<br />TREATMENT
<br />ASPH.
<br />PROPOSED
<br />DMA#
<br />IMPERVIOUS
<br />PERVIOUS
<br />IMPERVIOUS
<br />3.2
<br />AREA
<br />SIZING
<br />V 2C
<br />AREA (SF)
<br />AREA (SF)
<br />REQUIRED
<br />PROVIDED
<br />__
<br />AREA (SF)
<br />I
<br />--- L
<br />(SF)
<br />RATIO
<br />1
<br />7,785
<br />4,551
<br />8,240
<br />330
<br />355
<br />4%
<br />2
<br />36,629
<br />14,764
<br />38,105
<br />1,524
<br />1,617
<br />4%
<br />1
<br />8,646
<br />2,114
<br />8,857
<br />354
<br />356
<br />'-AN 3C
<br />EE -
<br />3,749
<br />36
<br />3,753
<br />L --
<br />JV MAIN STREET LLC
<br />4%
<br />IMP
<br />2
<br />21,465
<br />•
<br />I —
<br />2,493
<br />� 5 \�
<br />Ml 1
<br />LOW FLOW
<br />DIS TRI,3U TION•
<br />I Fm'/'A PUMP PIPE
<br />DMA 3
<br />I -IMP 4
<br />.II i
<br />lig ® • r / r CARDINAL
<br />.lim
<br />is ? I
<br />.11 � j►j �
<br />IIS -
<br />.II r
<br />1�2:z
<br />■II1= I 0
<br />.I�
<br />171,E
<br />-
<br />���i" 1� Ili,
<br />—
<br />� EN E
<br />DECK z 0 S\
<br />o =
<br />o U CL
<br />I Q I z
<br />I
<br />2�pJA r I�
<br />548 (1
<br />i JJ '5 , J
<br />)49 3 — r _r ---1--- 3�g `� ----- — -1—
<br />El 3
<br />CONC. 5
<br />35g 1 BERM
<br />o -
<br />c) I x g0
<br />BENS — ASPH. I _ ASPH.
<br />STORMWATER TREATMENT CALCULATIONS
<br />STORM WATER
<br />TREATMENT
<br />PLAN-
<br />EFFECTIVE
<br />TREATMENT
<br />TREATMENT
<br />PROPOSED
<br />DMA#
<br />IMPERVIOUS
<br />PERVIOUS
<br />IMPERVIOUS
<br />AREA
<br />AREA
<br />SIZING
<br />AREA (SF)
<br />AREA (SF)
<br />REQUIRED
<br />PROVIDED
<br />AREA (SF)
<br />(SF)
<br />(SF)
<br />RATIO
<br />1
<br />7,785
<br />4,551
<br />8,240
<br />330
<br />355
<br />4%
<br />2
<br />36,629
<br />14,764
<br />38,105
<br />1,524
<br />1,617
<br />4%
<br />1
<br />8,646
<br />2,114
<br />8,857
<br />354
<br />356
<br />4%
<br />4
<br />3,749
<br />36
<br />3,753
<br />150
<br />165
<br />4%
<br />TOTAL
<br />56,809
<br />21,465
<br />58,956
<br />2,358
<br />2,493
<br />NA
<br />PRELIMINARY
<br />STORM WATER
<br />TREATMENT
<br />PLAN-
<br />TRACT8631 -
<br />475 AND 493
<br />SAINT JOHN
<br />STREET
<br />CITY OF PLEASANTON, ALAMEDA COUNTY, CALIFORNIA
<br />FOR: ROBSON HOMES, LLC
<br />0 30 60 90
<br />1 inch = 30 ft.
<br />NO TES:
<br />1. THE ABOVE CALCULAT/ONS ARE BASED ON THE ALAMEDA COUNTYWIDE
<br />CLEAN WATER PROGRAM, C. 3 STORMWA TER TECHNICAL GU/DANCE,
<br />DATED FEBRUARY 8, 2021, AND THE FOLLOWING CRITERIA:
<br />a. EFFECTIVE IMPERVIOUS AREA = IMPERVIOUS AREA + 10q OF
<br />PERVIOUS AREA
<br />b. 0.2 INCHES/HOUR RAINFALL INTENS/TY ON 100q OF EFFECTIVE
<br />IMPERVIOUS AREA.
<br />c. SOIL FOR TREA TMEN T MED/UM WITH A 5 INCHES/HOUR
<br />INF/L TRA TION RA TE.
<br />d. SIZING FACTOR OF 0.04 /S CALCULATED ON THE FOLLOW/NG
<br />CR/TER/A:
<br />a. (0.2 /N/HR)/(5 /N/HR)= 0.04
<br />C3 STORMWA TER TREATMENT CALCULATIONS-
<br />1.
<br />ALCULATIONS.•1. PRE -DEVELOPMENT IMPERVIOUS SURFACE AREA = 58,180 SF
<br />2. HYDROMOD/F/CATION /S NOT REQUIRED SINCE POST DEVELOPMENT
<br />IMPERVIOUS AREA /S LESS THAN PRE -DEVELOPMENT COND/770N.
<br />LEGEND
<br />® PROPOSED S/LVA CELLS
<br />DRAINAGE MANAGEMENT AREA (DMA)
<br />AX 11.
<br />RUGGERI-JENSEN-AZAR
<br />ENGINEERS ■ PLANNERS ■ SURVEYORS
<br />4690 CHABOT DRIVE, SUITE 200 PLEASANTON, CA 94588
<br />PHONE: (925) 227-9100 FAX: (925) 227-9300
<br />NO. DATE DESCRIPTION BY
<br />DATE: MAY 22, 2024
<br />JOB NO.: 201054
<br />SHEET NO.
<br />TM6ml
<br />
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