20140209 Ver 1_7 Bio-Retention 1_20211130

F\-Nct
tt-c
l
D
RETAINING
WALL (2'±)
CLEAN -OUT
(TYPICAL)
4" PVC
F I CAL)
SOTTO IV S U FAC E
AREA = 2,33G SE '}
(ELEV.=322.65)
20'
5E
OA 5AN'
EASE.
►� at Corners
Appantr ato
Lireao
En evallon
OttIailead HAD
For cot applications: or as
directed by geotechteral meiotic
when site ctieditions radalre,--
piece drainage c rrintattia
Mkali GIOON for equivrleui)
installari it 20- wa33 he phi
and 30% coverage.
°" Mkt. Low Petreaa We Sziii
a' Perforated PVC Drainage Tile,_
Outlet query 5fi' 0.C,
(when Site Conditions Require)
Sae rote betow.
4' Perforated PVC or
HOPE Dralnega
outlet every ,O' O.C.
Nr�t�t:
As directed by isediester v fs rt a32a candltiona tedukrn, wrap
deer/svelte In Pa or Y%i W I stone and Sox nonw'vrati Met
Nano and pla'm with deefnc>LWW oaroptasfia iwytqwedadt bank &sift
eyxrmn,
Typical Reinforced Wall Section
:r=i? Ciatea.da FiTi
3;4• Crashed
Pnsk r Stone)
Levelled Ped
Nate:.
ebiL SEARING CAPACITY OF
3,fitT,7 PSF IS ASSUMED
NOTES:
I . RETAINING WALLS MUST BE A MEDIUM OR. DARK BROWN OR RUST COLOR.
2. RETAINING WALL DETAIL REPRESENTS THE WALL TYPE TO BE USED AT THIS SCM.
•
•
•
•
G" PVE
INV.
318.p1
WETLANDS
(TYPICAL)
0`2
EIV OVEX. I 5" �\
EES $ INSTALL
HEADWALL
INV. =323.66 (-I-)
FOREBAY
DETAINING
WALL (<3')
\
\
\
\
STORMWATEBfVP
ACCESS fVAINTENANCE
EASEMENT
\
\
\
\
TOP Of BEAM
-325. 15
E/ E KG ► N CY SPILLWAY
CEIVIE_Kt ENCY
-- 5-I-LLWA DITCH
5'x 5' I P- RAP
PAD (D5o=")
STRUCTURAL BMP CONSTRUCTION SEQUENCE:
THE FOLLOWING MUST OCCUR. PRIOR TO FINAL PLAT AND/OR CERTIFICATE OF OCCUPANCY (CO):
1. ALL STRUCTURAL BMP5 MUST BE INSTALLED IN ACCORDANCE WITH THE APPROVED CONSTRUCTION DRAWINGS.
2. THE DESIGN ENGINEER MUST SUBMIT AN AS -BUILT PACKAGE WHICH MEETS ALL REQUIREMENTS PRESENTED IN THE
TOWN SPEC BOOK INCLUDING A SIGNED AND SEALED CERTIFICATION STATEMENT.
3. SUBMIT THE APPROPRIATE SIGNED STRUCTURAL BMP OEM AGREEMENT AND MAINTENANCE GUARANTEE TO THE
DEVELOPMENT PROJECTS COORDINATOR IN CONSTRUCTION MANAGEMENT AT 249-3394,
4. A FINAL INSPECTION BY THE ENVIRONMENTAL PROGRAMS MANAGER SHALL BE CONDUCTED ONCE THE AS -BUILT
SUBMITTAL HAS BEEN RECEIVED. ONCE APPROVED, THE ENVIRONMENTAL PROGRAMS MANAGER WILL SEND A BMP
APPROVAL LETTER TO THE OWNER.
5. IN LIEU OF STRUCTURAL BMP COMPLETION AND FINAL APPROVAL BY THE ENVIRONMENTAL PROGRAMS MANAGER, THE
TOWN MAY ACCEPT A PERFORMANCE GUARANTEE IN ACCORDANCE WITH UDO SECTION 6. I . 12(G). IF THE CONTRIBUTING
DRAINAGE AREA FOR THE BMP5 I5 UNSTABLE AT THE TIME OF FINAL PLAT APPROVAL FOR. A SUBDIVISION, THE TOWN
WILL ALLOW A SKIMMER SYSTEM TO BE CONNECTED TO THE EMERGENCY DRAIN SIZED TO DE -WATER THE VOLUME OF
THE BASIN OVER A 2-3 DAY PERIOD. POROUS BAFFLES SHALL EITHER CONTINUE TO BE MAINTAINED (IF CONVERTING
FROM A SEDIMENT BASIN) OR BE INSTALLED. ANY ORIFICES MUST BE CAPPED OR PLUGGED.
6. ALL STRUCTURAL BMPS ARE REQUIRED TO BE COMPLETED PRIOR TO A FINAL CO FOR. A SITE PLAN AND ISSUANCE .OF
90% OF COS WITHIN A SUBDIVISION. IF THE SUBDIVISION'S TO BE PHASED, ALL STRUCTURAL BMPS SHALL BE
COMPLETED PRIOR TO ISSUANCE OF 90% OF COS WITHIN THAT PHASE.
7. IF A STRUCTURAL BMP COUNTS TOWARDS RCA, THE REQUIRED LANDSCAPING SHALL BE INSTALLED DURING THE
APPROPRIATE GROWING SEASON AND COORDINATED WITH THE TOWN ZONING COMPLIANCE OFFICER AT 249-3426.
BIOETENTION LAYOUT:
STANDARD COSS-SECTION
I I
I I I
III
-IN SITU SOIL
PERMENANT
CLEANOUT POST WI
CLEANOUT MARK
BOTTOM AND
SLOPES STABILIZED CAPPED CLEAN
WITH BERMUDA OUT PIPE
SOD L
1 2" PONDING
FILL SOIL MEDIA
MIX: 85-88% SAND,
8-I 2% FINES
3 5% ORGANIC
DEPTH: TREES/SHRUBS-aft.
GRASS=2ft.
4" W'
21+ DISTANCE
TO WATER
TABLE
HED SANE
-UNDERDRAIN
�FILTER FABRIC_
(OR CHOKING -
STONE) -
-WATER TABLE-
BIORETENTION AREA
AS-DUILT
REVISION
MINIMUM WEIR
LENGTH (FT)
10
10
UNDERDRAIN PIPE
DIAMETER. (IN)
4
4
MINIMUM NUMBER OF
UNDERDRAIN PIPES
2
2
CLEANOUT
ELEVATION (FT)
323. 17
323.17
TOP OF BIORETENTION
SOIL MIXTURE ELEV. (FT)
322.65
322.65
BOTTOM OF BIORETENTION
SOIL MIXTURE ELEV. (FT)
320.65
320.65
SPILLWAY (WEIR)
ELEVATION (FT)
324.04
324.15
TOP OF BERM
ELEVATION (FT)
324.82
325.15
MINIMUM
DEPTH= 12"
('•?.,
\///\/\
RIP -RAP
D5o=6"
BOTTOM WIDTH = 2'
WITH GEOTEXTILE LINER
NOTE:
RIP -RAP SHALL EXTEND TO THE EDGE OF THE GEOTEXTILE LINER.
EXISTING
GROUND
EMVEKGENCY SPILLWAY DITCH DETAIL
N.T.S.
UNDERDRAIN PIPE SHALL BE SCHEDULE 40 PVC,
SDR35, OR SMOOTH WALL CORRUGATED PLASTIC
PIPE WITH 3/8' PERFORATIONS AT 6" ON CENTER (4
HOLES PER ROW) REFER TO TABLE FOR PIPE SIZE.
\��/\\\/\\ /�\ \/\\//\//\ /f\\//\�' \//\\/�\\// \/` \<\•
CLASS "C"
GEOTEXTILE
FABRIC AROUND
WASHED STONE
UNDERDRAIN PIPE
TO BE INSTALLED AT
0.5% MIN. SLOPE
4i
TOP OF
BIORETENTION
POND
BOTTOM OF
ENGINEERED FILL
MATERIAL
PERMEABLE FILTER
FABRIC LINING ENTIRE
BIORETENTION CELL
WASHED 57 STONE
ENVELOPE
RETAINING
WALL
ENGINEERED FILL
MATERIAL
HOPE
CLEANOUT
1 O0-YEAR STORM EL - 324.65
10-YEAR STORM EL - 324.45
I -YEAR STORM EL - 324.25
UNUNED SLATTED
HDPE UNDERDRAIN
PERMEABLE FILTER
FABRIC OVER ENVELOPE
TOP OF EARTH DAM
EL m 325.15
TOP OF EMERGENCY SPILLWAY
EL - 324.15
OUTLET PIPE
INVERT OUT
BIO-RETENTION BMP CROSS-SECTION (N.T.S.)
BIORETENTION SOIL NOTES:
BIORETENTION SOIL MIXTURE (BSM): SHALL BE PLACED AND GRADED USING LOW GROUND -CONTACT PRESSURE
EQUIPMENT OR BY EXCAVATORS AND/OR BACKHOES OPERATING ON THE GROUND ADJACENT TO THE BIORETENTION
FACILITY. NO HEAVY EQUIPMENT SHALL BE USED WITHIN THE PERIMETER OF THE BIORETENTION FACILITY BEFORE,
DURING, OR AFTER THE PLACEMENT OF THE BSM. THE BSM SHALL BE PLACED IN HORIZONTAL LAYERS NOT TO
EXCEED 12 INCHES FOR THE ENTIRE AREA OF THE BIORETENTION FACILITY. THE BSM SHALL BE COMPACTED BY
SATURATING THE ENTIRE AREA OF THE BIORETENTION FACILITY AFTER EACH LIFT OF BSM 15 PLACED UNTIL WATER
FLOWS FROM THE UNDERDRAIN. WATER FOR SATURATION SHALL BE APPLIED BY SPRAYING OR SPRINKLING. AN
APPROPRIATE SEDIMENT CONTROL DEVICE SHALL BE USED TO TREAT ANY SEDIMENT -LADEN WATER DISCHARGED
FROM THE UNDERDRAIN. IF THE BSM BECOMES CONTAMINATED DURING THE CONSTRUCTION OF THE FACILITY, THE
CONTAMINATED MATERIAL SHALL BE REMOVED AND REPLACED WITH UNCONTAMINATED MATERIAL AT NO ADDITIONAL
COST TO THE ADMINISTRATION. FINAL GRADING OF THE BSM SHALL BE PERFORMED AFTER A 24-HOUR SETTLING
PERIOD. FINAL ELEVATIONS SHALL BE WITHIN 2 INCHES OF ELEVATIONS SHOWN ON THE CONTACT PLANS.
THE BIORETENTION SOIL MIXTURE (BSM) SHALL BE A UNIFORM MIX, FREE OF STONES, STUMPS, ROOTS, OR OTHER
SIMILAR OBJECTS LARGER THAN 2 INCHES EXCLUDING MULCH. NO OTHER MATERIALS OR SUBSTANCES SHALL BE
MIXED OR DUMPED WITHIN THE BIORETENTION AREA THAT MAY BE HARMFUL TO PLANT GROWTH, OR PROVE A
HINDRANCE TO THE PLANTING OR MAINTENANCE OPERATIONS.
PRIOR TO PLACING THE UNDERDRAIN AND THE BSM, THE BOTTOM OF THE EXCAVATION SHALL BE ROTO-TILLED TO A
MINIMUM DEPTH OF 6 INCHES TO ALLEVIATE ANY COMPACTION OF THE FACILITY BOTTOM. ANY SUBSTITUTE
METHOD FOR ROTO-TILLING MUST BE APPROVED BY THE ENGINEER PRIOR TO USE. ANY PONDED WATER. SHALL BE
REMOVED FROM THE BOTTOM OF THE FACILITY AND THE SOIL SHALL BE FRIABLE BEFORE ROTO-TILLING.
NOTES:
1. ALL MATERIALS AND METHODS OF CONSTRUCTION SHALL BE IN ACCORDANCE
WITH TOWN OF APEX STANDARDS AND SPECIFICATIONS.
2. BOUNDARY TAKEN FROM A DIGITAL FILE PROVIDED BY BARRY SCOTT SURVEY
COMPANY.
3. TOPOGRAPHIC INFORMATION TAKEN FROM WAKE COUNTY GIS FILES.
4. THIS SITE HAS BEEN REVIEWED FOR WETLANDS AND STREAM BUFFERS BY
ENVIRONMENTAL SERVICES INC. AND THE DELINEATED ENVIRONMENTAL FEATURES
HAVE BEEN SHOWN.
5. PER FEMA MAP #37200721 OOJ DATED 02 MAY 2006, NO 1 00-YEAR
FLOODPLAIN TRAVERSES THE PROPERTY.
6. CONTRACTOR SHALL HAVE NORTH CAROLINA ONE CALL (1-800-632-4949)
LOCATE ALL EXISTING UTILITIES PRIOR TO BEGINNING CONSTRUCTION.
7. THIS SITE IS LOCATED WITHIN THE PRIMARY WATERSHED PROTECTION
OVERLAY DISTRICT.
8. THE BIO-RETENTION AREA SHALL BE LOCATED WITHIN A DRAINAGE EASEMENT
WITH ACCESS TO A PUBLIC R/W.
9. THIS SCM WAS CERTIFIED ON I I/02/19 AND 05/07/20 BUT NOT ACCEPTED
BY THE TOWN OF AEX BECAUSE THE MADISON H0A OBJECTED TO PROVIDING
A LETTER ACCEPTING MAINTENANCE OF THE CONSTRUCTED EMBANKMENT
SLOPES.
W
BIOETENTI ON CELL: FO.EBAY DETAIL
GRASS
/f \ ,,,„//X/\/%
11
CLASS B RIP -RAP
D5o= 1311
3011
FABRI-C
(SEE NOTE 3 UNDER
I0/25/21 REVISION)
I O'x 10' (±) PLUNGE POOL
•
i
\
//\
OUTLET
PIPE
REFER TO GRADING
PLAN FOR TOP OF
DAM ELEVATION
5' WEIR LENGTH
REFER TO GRADING
PLAN FOR SPILLWAY
ELEVATION
3
•
SPILLWAY BOTTOM AND
SLOPES TO BE STABILIZED
WITH PERMANENT EROSION
CONTROL MAT
PERMANENT EROSION MAT TO BE
P-300 BY NORTH AMERICAN GREEN,
MIRAMAT BY MIFAFI CORP., OR
APPROVED EQUAL
SECTION ThROUGI-1 SPILLWAY (NT5)
0
5
GAPI-11C SCALE
20
03/09/21 REVISION:
THE PURF'OSE OF THIS REVISION 15 TO APPROVE THE GRADING AND RETAINING WALLS NECESSARY TO
PROVIDE 3:1 INTERIOR SLOPES FOR THE 5CM. THE SCM DESIGN PARAMETERS SHALL BE CONFIRMED BY
THE CONTRACTOR FOR CERTIFICATION. ANY LANDSCAPING PLANTINGS IMPACTED BY GRADING SHALL BE
REPLACED.
09/05/21 REVISION:
I. THE F'URPOSE OF THIS REVISION 15 TO APPROVE THE SCM A5 ORIGINALLY CONSTRUCTED INCLUDING
ALL EXISTING SLOPES. THE UNDERSTANDINGI5 THAT THEHOA WILL PROVIDE A LETTER OF
ACCEPTANCE FOR THIS REVISION.
2. THIS REVISION INCLUDES THE REMOVAL OF THE GEOTEXTILE FABRIC UNDER THE FOREBAY RIP -RAP.
NONE WA5 INSTALLED IN THE ORIGINAL CONSTRUCTION AND IS EXPECTED TO PROVIDE BETTER
INFILTRATION OF STORMWATER.
3. THE EXISTING TOPO AND BIO-RETENTION INFORMATION WAS TAKEN FROM AN AS -BUILT SURVEY.
I. GEOTECHNOLOGIES, INC. COMPLETED A FIELD INVESTIGATION OF THE BERM FILL AND DO NOT
RECOMMEND ANY MODIFICATIONS A5 OUTLINED IN THEIR I 0/21/2 I REPORT.
2. THE REHABILITATION WORJK OUTLINED UNDER THE 03/09/2 I REVISION AND SHOWN HEREON SHALL BE
IMPLEMENTED FOR 5CM CERTIFICATION UNLESS A LETTER FROM THE MADISON HOA IS PROVIDED
ACCEPTING THE 5CM AS CONSTRUCTED WITHOUT CONDITIONS.
3. FABRIC SHALL BE PLACED UNDER THE RIP -RAP FOR, THE FOREBAY IF INSTALLED DIRECTLY ON IN -SITU
50IL5 AND/OR FILL. IF THE RIP-RAPI5 PLACED ON SOIL MEDIA, NO FABRIC IS REQUIRED.
4. RETAINING WALLS SHALL BE SEGMENTED BLOCK TINTED MEDIUM OR DARK BROWN OR RUST IN
COLOR. ALL PERMITTING WILL BE HANDLED AS A SEPARATE SUBMTTAL.
5. FENCING SHALL BE INSTALLED AT THE TOF' OF RETAINING WALLS IF REQUIRED BY THE BUILDING CODE.
THE SIGNATURES AFFIXED BELOW CER,TIFY THAT THIS SHEET HA5 BEEN REVIEWED AND APPROVED SOLELY
PER THE CERTIFICATIONS SIGNED ON TI1E COVER SHEET OF THESE CONSTRUCTION PLANS.
PW - TRANSPORTATION DATE
BUILDING INWNTIONS
unifier 12/02/2021 2:00:58 PM
WR, - UTILITY ENGINEERING
rsmith 11/30/2021 4:19:42 PM
ELECTRIC
Approved
Approved
DATE PLANNING
DATE
DATE
DATE PLANNING - TRANSPORTATION DATE
DATE FIRE
DATE
DATE PARKS, RECREATION CULTURAL RES, DATE
Jones & Cnossen
ENGINEER
Construction Management
Civil Engineering
SUITE 001
PO BOX 1062
APEX, NC 27502
Office: 919-387-1174
Registration: P-0151
' y;
,24
CONSTRUCTION DRAWINGS
SCALE
DATE
aL
OZ
Lil
0
TOWN OF
DRAWN
5MJ
REVISION
03/1 3/1 4
1st TRC COMMENTS
04/17/15
BIO-AREA GRADING
GRADING REVISION
TRC COMMENTS
TRC COMMENTS
09/08/2 1
GRADING REVISION
SHEET
7
PROJECT
DESIRED BIORETENTION SOIL MIXTURE PH LIES BETWEEN 5.5 AND 6.5.