HomeMy WebLinkAboutWPO201400084 Correspondence 2020-08-04Pursuant to 9VAC25-870-55, I hereby certify that to the best of my knowledge and belief
the stormwater management facilities shown on these record drawings have been
constructed in accordance with the approved plans and specifications.
Jeremy M. Lynn
Name
Lic. No. 043041
Virginia License
gnature
August 4, 2020
Date
"Certify means to state or declare a professional opinion based on sufficient and
appropriate onsite inspections, material tests, as -built survey data, and information
provided by other professionals and the contractor, conducted during or after
construction.
ELEV OF 364.0
BIORETENTION SOIL LAYER 3'
PEA GRAVEL LAYER " 1' `
STONE LAYER 1•
CONNECnON TO
6" PVC PIPE
6" SOLID PVC PIPE. CAPPED
(PLACE 1' ABOVE SOIL )
- Tr CONNECTION
DIAMETER PERFORATED UNDERDRAIN
1X SLOPE
LONGITUDINAL
CROSS SECTION
NOT TO SCALE
IN
.51 k/
SITE NCE -1,
E
T
r
GR
400
390
370
360
7
9+75
350
0 20 40 60
GRAPHIC SCALE: 1 "= 20' HORIZ.
Albemarle County DESIGNED:
Service Authority DRAWN:
Serving ♦ Cwsemnq
CHECKED:
r'
ELEV OF 364.0
THE THE E XIS SHOULD D TIED
INTO THE EXISTING GROUND
wrrH AT LEASr 2' OF GROUND
ABOVE THE GEOTM E
GEOTEXTILE (ALONG
CROSS SECTION
NOT TO SCALE
D GROUND
365.0 Fr
GEOTEXnLE (HANG SIDES)
DIAMETER PERFORATED UNDERDRAIN
DEPTH
VOID RATIO
VOLUME (FT3)
SURFACE STORAGE
1
1
338
BIOSOIL
3
0.25
253.5
GRAVEL
1
0.4
135.2
TOTALSTORAGE=
726.7
0.5'
GRASS SWALE TYPICAL
CROSS SECTION
NOT TO SCALE
0 O TAX MAP 093A1-00-00-00400'
RIVANNA VILLAGE LLC
36` �D;B. 4375, PG. 410)
Z9�'
\ 3 S
V �0 RO -S 10 �-
\ `DET L, THIS EET�
\ �\
\ � ) CEPHALANTHUS
\\ C�IDENTALIS/BUTTON
�1 \ USi -
�� 8 S.Y.
CLASS I D RIP AP 368 \ 20) BLCKIA
W/ F'FLTER F RIC "`������ A LACI(-EYED
UNDERLI�ING BE AD TO DRAIN1, S
TOWARD StRASS SWAL ♦ 37o
\ PUMP TATIO
\ B RETE ION
\ FACILI Y OU NE
\ I V. IN= 4
;1• A SE CRO S SECTI N
DET lLS, IS SHE
�
A { �� 12" DI,P WATER
"1 �' DISCHARGE LINE
8„ CO C.
41.
.: CORM PIPE
STA. 0+ Q ±" 4 LF 2.2% SLOPE
DROP .I i w 'e �.. 6 PVC
_ Y BIORETENTION DRAIN PIPE
O11T �4 ' EXTEND TO DAYLIGHT
s j \
TAX MAP 093A1-00-00-00200 STA. 1 +24 STA. 1 +68
EAST RIVANNA VOLUNTEER STORM \ INV. OUT=366.5
18" CONC. STORM FIRE CO. INCORPORATED WATER MANHOLE v
PIPE #3501 STEAMER DRIVE RIM-370.5 \\ 13 S.Y.
/ 124LF @ 2.2% SLOPE (D.B. 1204, PG. 201) INV IN=367.0 \ CLASS DRY RIP RAP
SCALE: INV. OUT=366.9 \� �\ 12'9UN THICK W/, FILTER FABRIC
/ 1"=20' HORZ:, �\ UNDERLINING
STORMWATER MANAGEMENT AND PLANTING PLAN
400
011
AGE', TANK
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-
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Z z_
GRADE
EIVD WALL VDUI LW-138
13 S.Y.
CLASS I DRY RIP RAP
12" THICK 'W/ FILTER FABRIC
NDERLININ '
39
37
36
-PROP
--
-------
x. Grade
-
-
-_- _
_
-------
18'
STORM
-------
CONC.
PIPE 18" CONC.
STORM PPE
20LF @ 2.2% SL PE
M
+
O
O
+
0 20 40 60
ZMC
JLB
GDG 1 12-5-19 RECORD DRAWINGS
NO. DATE REVISION
80 100 20 40 60
STORMWATER PROFILE
N0. DATE
80 200
REVISION
1
J
1
1
350
STORMWATER COMPUTATION AND BMP CALCULATIONS
OUTFALL
THE NATURAL TOPOGRAPHY OF THE SITE DROPS OFF IN THE SOUTH DIRECTION. THE RELATIVELY SMALL FLOW
RATES EXPECTED FROM THE UNDERDRAIN AND THE EMERGENCY SPILLWAY (DURING INFREQUENT STORM
EVENTS) SHOULD NOT RESULT IN EROSION OR ANY OTHER DOWNSTREAM ISSUES. A SOLID POLYVINYL PIPE
WILL CONNECT THE PERFORATED UNDERDRAIN PIPE TO THE OUTFALL LOCATION.
VEGETATED EMERGENCY SPILLWAY
THE PEAK FLOW RATE TO THE BIORETENTION AREA IS APPROXIMATELY 1.1 CFS DURING THE 100-YR OR
1-PERCENT-ANNUAL-CHANCE STORM EVENT. WHEN THE DEPTH OF WATER ABOVE THE BIORETENTION AREA
REACHES 0.5-FT, THE EMBANKMENT ON THE WEST SIDE OF THE BIORETENTION BASIN WILL ACT AS A
SPILLWAY ALLOWING WATER TO SPILL OVER THE SIDE AND DOWN THE EXISTING HILL. NO STRUCTURES ARE
FOUND IN THE IMMEDIATE AREA DOWNSTREAM OF THE EMBANKMENT.
GRASS SWALE
TWO GRASS SWALES SHALL BE CONSTRUCTED TO CONVEY WATER FROM THE IMPERVIOUS AREAS TO THE
BIORETENTION AREA. THE SWALES ARE SIZED FOR THE 10-YR OR 10-PRECENT-ANNUAL-CHANCE STORM
EVENT AND WERE ANALYZED USING THE FLOWMASTER PROGRAM. THE MINIMUM DIMENSIONS ARE AS FOLLOWS:
BOTTOM WIDTH = 0.5 FT
TOP WIDTH = 3.5 FT
DEPTH = 0.5 FT
SIDE SLOPES = 3 TO 1
PLANT AND COMPOSITION SCHEDULE
BIORETENTION
SIZE ( acres) : .008 AC (338 SF/13'x26')
OVERALL SPACING
(FEET OFF CENTER)
QUANTITY
PER ACRE
FREQUENCY
I %)
SPECIES
QUANTITY
BOTANICAL NAME
COMMON NAME
UNIT
10
520
17%
4
CEPHALANTHUS OCCIDENTALIS
BUTTONBUSH
30"HT.
2
2600
83%
20
RUDBECKIA HIRTA
BLACK-EYED SUSAN
QT.
NOTES:
1. CLUSTERING AND ARRANGEMENT OF THESE SPECIES TO BE COORDINATED WITH ACSA STAFF.
2. PLANT SPECIES ARE PER THE ALBEMARLE COUNTY RECOMMENDED PLANTS LIST.
Virginia Runoff Reduction Method ReDevelopment Worksheet - v2.8 - June 2014
Site Data Summary
Total Rainfall = 43 inches
Site Land Cover Summar
y
Forest (acres)
Turf (acres)
Impervious (acres)
A Soils
B Soils
C Soils
D Soils
0.00
0.00
0.00
0.00
0.00
0.35
0.00
0.00
0.00
0.09
0.00
0.00
Site Rv
0.35
Post Development Treatment Volume (ft3)
547
Post Development TP Load (lb/yr)
0.34
Post Development TN Load (lb/yr)
2.46
Total TP Load Reduction Required (lb/yr)
0.28
Total Runoff Volume Reduction (R3)
452
Total TP Load Reduction Achieved (lb/yr)
0
Total TN Load Reduction Achieved (lb/yr)
2.33
Adjusted Post Development TP Load (lb/yr)
0.02
Remaining Phosphorous Load Reduction (Lb/yr) Required
0.00
Drainage Area Summary
Update Summary Sheet
Pri nt
Total
% of Total
0.00
0.00
0.35
80.33
0.09
19.67
0.43
100.00
RECORD DRAWING
THIS DRAWING HAS BEEN REVISED
TO SHOW ALL KNOWN CHANGES MADE
DURING CONSTRUCTION AND REFLECTS
TO THE BEST OF OUR KNOWLEDGE
THE FACILITIES AS CONSTRUCTED
Michael Baker
DATE 1Z/o61ZO19 BY 2'ZI
D.A. A
D.A. B
D.A. C
D.A. D
D.A. E
Total
Forest (acres)
0.00
0.00
0.00
0.00
0.00
0.00
Turf (acres)
0.35
0.00
0.00
0.00
0.00
0.35
Impervious (acres)
0.09
0.00
0.00
0.00
0.00
0.09
0.43
Drainage Area Compliance Summary
D.A. A
D.A. B
D.A. C
D.A. D
D.A. E
Total
TP Load Red. (lb/yr)
0.32
0.00
0.00
0.00
0.00
0.32
TN Load Red. (lb/yr)
2.33
0.00
0.00
0.00
0.00
2.33
DRAINAGE SUMMARY TABLE
STRUCTURE
NUMBER
DESCRIPTION
LENGTH
INVERTIN
INVERT OUT
SLOPE
REMARKS
1
DI-7
N/A
N/A
369.5
N/A
4' MANHOLE
2
18" RCP, CLASS III
124'
N/A
N/A
2
N/A
3
MANHOLE
N/A
366.5
366.4
N/A
4' MANHOLE
4
18" RCP, CLASS III
56'
N/A
365.5
4
N/A
0 10 20 30
GRAPHIC SCALE: 1 "= 10' VERT.
J U LY 2017
272 BENDDC ROAD, SUTI'E 400
GLENMORE GROUND STORAGE
TANK, PUMP STATION, AND WATER
MAIN PROJECT (PROJECT N0. 2013-04)
VHZGINIA BEACH, VA 23452
TAX MAP
SHEET
PHONE: 7)463-0503 0
INTERNATIONAL FAX: (757) 463-0503
STORMWATER
MANAGEMENT PLAN
AND CALCULATIONS
°079'
SW 1