20050732 Ver 47_SMP Mod Approval_20190411

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ROY COOPER
Governor
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MICHAEL S.REGAN « „0
Secretary
LINDA CULPEPPER NORTH CAROLINA
Director Environmental Quality
April 11,2019
DWR#2005-0732v47
Chatham County
Mr.Lee Bowman, Senior Project Manager
NNP-Briar Chapel, LLC
1342 Briar Chapel Parkway
Chapel Hill,North Carolina 27516
Subject: APPROVAL OF STORMWATER MANAGEMENT PLAN MODIFICATION
Briar Chapel—Granite Mill Boulevard
Dear Mr.Bowman:
The Division of Water Resources(Division)recently received a request from McKim&Creed,Inc.on your
behalf to modify the existing stormwater management plan(SMP)as previously approved by the Division
under#2005-0732v17.
The Division hereby approves the design change of the bioretention cell to a stormwater wetland with the
same pond's footprint, as shown on the revised engineering plans dated February 8, 2019. The maximum
allowable drainage and built-upon areas are reduced to 303,601 ft2 and 151,028 ft2,respectively.All other
aspects of the stormwater management plan shall continue as previously approved by the Division.
Please contact Chonticha McDaniel at(919)707-3634 or chonticha.mcdaniel(&ncdenngov if you have any
questions or concerns regarding this matter.
Sincerely,"lJ,- x q�l `
Karen Higgins, Supervisor
401 &Buffer Permitting Branch
cc: Gareth Avant,P.E.—McKim&Creed,Inc. (via email)
DWR,Raleigh Regional Office
DWR 401 &Buffer Permitting Branch File
North Carolina Department of Environmental Quality I Division of Water Resources
D_E Q� 512 North Salisbury Street 1 1617 Mail Service Center I Raleigh,North Carolina 27699 1617
�v� /� 919.707.9000

1. GLEANOUTS SHALL BE GUT OFF AND GAPPED BELOW PROPOSED GRADE
1. AVOID COMPACTING TOPSC ;_ TO PROMOTE HEALTHY ENVIRONMENTAL CONDITIONS FOR THE PLANTS.
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2. PLANTS OF THE SAME SPE0IES SHOULD BE PLANTED IN CLUSTERS, THESE CLUSTERS SHOULD CONTAIN MIN. 4-6
PLANTS OF THAT SPECIES.
3. ALL PLANTS SHOULD BE PANTED IN THE INDICATED RANGE TO ENSURE SURVIVAL,
A. AVOID PLANTING INDIVIDUA: SPECIES IN LARGE GROUPS BY SPACING CLUSTERS A MIN. OF 5, APART.
/ �� �c �a� ��? OW LAND AREAS TO BE PLANTED WITH BARE ROOT, PLUG OR CONTAINER LIVE
f
PR SHALLOW WATER AND SHALLOW T, S,
PLANTINGS AS SPECIFIED.
6. EXCAVATE A HOLE TWICE 7-1E DIAMETER OF ROOT BALL AND EQUAL TO THE ROOT DEPTH OF THE INDIVIDUAL PLANT.
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DEEP TTTL INLET ! � '�\ \� PLACE PLANT IN HOLE WITS CROWN FLUSH WITH SOIL SURFACE, BACKFILL WITH TOPSOIL AND LIGHTLY PLANT.
IV- - �� �ti jo \fll- 7. BEGIN PLANTING DURING LOCAL GROWING SEASON IN ORDER TO ENSURE THAT PLANTS HAVE ADAQUET TIME TO
f ! F �� r ' ESTABLISH BEFORE WINTER MONTHS.
BOTTOM EL. 4,35. T
_ := 7
� �, 9. . �, - OW MARSH FARMS
� _ / ; ,! L L OBTAIN PLANTS FROM: C�"ASTAL PLAIN CONSERVATION NURSERY (252-462 5707}, HELL
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- � �� ---`'�~ ( 19 742-120 CURE NURSERY 19 542 616 } OR ENGINEER APPROVED SUBSTITUTE.
i �--� / V ( L ( L - 300 BELOW)
0% OF SOFT STEM BULRLSH SHOULD BE PLANTED WITHIN 3-4 INCHES BELOW NORMAL POOL
SHALLOW WA (NORMAL POOL - 6- BELL
V V V V V V V V `_ \\ 2. 70% OF PICKERELWEED AN-7 70% OF ARROW ARUM SHOULD BE PLANTED WITHIN 5-6 INCHES BELOW NORMAL POOL.
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sT��T�� LAND AREA (�TYP.,} �
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\\ 3. SHOULD LAN WITHIN 0 2 INCHES BELOW NORMAL POOL.
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` f �� V V V r tr R v v ®v v S LAND (NO POOL - 12 ABOVE) � oi� LIZARDS TAIL AND 70% OF SOUTHERN BLUE FLAG IRIS SHOULD BE PLANTED IN THE 2-3
70% OF SWEETFLAG, 70%
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f 1 / INCHES BELOW NORMAL P.
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- - V V �, V V V V cr V V V V V \7 1x , < , _C V 70% OF SOFT RUSH SHOUl. <: BE PLANTED AT THE NORMAL POOL ELEVATION,
SHALLOW WAT� � AREA �TYP,� IVVVVVVVV VVVVVVV VV � VVVVVV `v Vv 7
i V V 'v` ' V 1717 V V V C V V V V 7 V 7 V c7 ! V V V V V l - V V V `
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V V V �' V V V VG' CTVQ � �7v7 v U' C7C7 �rCaCJ `J I •' G' `% `7Tr
i' `' 1 V V V V V 7 V '7 \ PLANTS IN THIS GROUP SHOULD NOT BE PLANTED IN AREAS THAT ARE INUNDATED FOR EXTENDED PERIODS,
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L. � ,r , .: .f 7 V V `V V V V V ,P V ~ V V V V � V V V A �i/E ND -. - AL POOL
- V V �, V i - �; _ STORM W TER TLA 70% OF CARDINAL FLOWER AND 70% OF BLUE LOBELIA SHOULD BE PLANTED WITHIN 0 1 INCH OF THE NORM
�'" _ a � �r t_� ELEVATION.
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rf '�, �-_ 3�-- - NORMAL �i/ TER SLl RT�1E
�- DEEP POOL OUTLET / � �� � � � - � � � ELEVA TITN 4T9. QT � CUT & REMOVE ANY
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! . ; a J J _ .._ ! _., I- J ,.... T S m1 _, _, COVERING AROUND RooTs ENSURE ALL PLANTS ARE PLACED IN WATER NO DEEPER THAN 24 INCHES BELOW NORMAL POOL
TOP EL. 4,3 , T _ , I r s I _�T I-- ; _ V v V 77 t , 1 w
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J r I PUSH ITN SOIL J v� I i 1 ' t CRo I I WETLAND MUST BE STABLL®LD WITHIN 14 DAYS OF CONSTRUCTION
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SURFACE
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�- r , _ CONTRACTOR SHALL E SOLELY RESPONSIBLE FOR LOCATING G. 1" � 1 I E LQCA NG AND PROTECTION OF EXISTING ABOVE AND BELOW
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..� ( � � r J � _.C�" I _1 __ -.J _� m. � .ROUND UTILITIES AND ST"`w1
< _ r CTURES. ANY AND ALL MAINS OR INDIVIDUAL SERVICES LINES PRESENTLY IN SERVICE
E PRINCIPLE SPILL A Y �'
L _ .0 J - , L .�
a J ,_mI ry_ J WHICH ARE DAMAGED DURi
/ F � � I f � �--"(" �-- ; , � I �- �--`(" : _ ,, . � �_, � G CONSTRUCTION HALL E REPAIRED IMMEDIATELY AT NO ADDITIONAL EXPENSE TO THE
\„ / / � I_� .:`.° .. ! r....v _J �._, �..,.: ;-1 ,.._J .,.a I....J �.-, ,_J I_ (`1 1 .-._� i_.. ........:. .I._,, I,,.:1. .J € ,.J ,..�, j .{� �....I�,_J F..-, ....._�n. C1 \, `u V ✓ =✓ i li
SEE DETAIL THIS SHEET //, II y J g UTILITY OWNER
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MODIFICATIONS � � �' _ _1 `- � _T --a � �- � � �> - ,� nr 7 -T - �-- -� S :I � -! � _� � J _.J �_ 7 V � �; x= /; °�` `"!' '�° 'k `�` '� `+` 't` i' 'F `f `d� 3. CONTRACTOR SHALL KEEP ALL PARKING AREAS AND STREETS ADJACENT TO THE CONSTRUCTION SITE CLEAN AND
\ 1-, r� . . . . �- -F -F . -F is + OPEN AT ALL TIMES DURIN, CONSTRUCTION:
i � _. .._ I ! r' --.I ,___' m.�._J �_..E � ,--' r--' e7 �7 V V C7 V V V V V V 7T C7 V V V � V V V C7 � V � ,m1 �.1 .�1 r_, �. � r a � 7 `*r .7 .,, ,,r S7 � ;
..I )i � i r-' C7 V G V �T V V V V V V V if `t7 �% Ci' �7 y V V V �.7 �J \? V C7 V V r-� ..x I ._a .-Y r' i �<7 VV �7 C7 �i �,' `;I t / / ! ^M �° °$' ,}' '�' �^ �- i- mh ^}' '$'
_. � � � � � �� � v V V �.� ';� --+-- v 1 � °� � v � ALL SHALLOW WATER AND HALLOW LAN( AREAS WITHIN THE. WETLAND CELL SHALL
,. _ �� c V .� \ �_ , BE TOP DRESSED WITH A MINIMUM
\ - ,_ V `� V V V V V Y �r�Q C7 VT 7 V it v V 17 V '7 � V �7 V -7 C7 V f `� � , V `7 C' ` � �/-- � � OF 12 IN OF TOPSOIL.
V V V` V -. _ '7 V V l V V V V V V V V 1 V V 17 V v `7 17 ` �/ /
r 1 V c 7 ? V V V V V V 47> 7, `7 , V V
q 5� ALL ITEMS WHICH ARE SHC`1VN FOR REMOVAL SHALL BE REMOVED FROM THE CONSTRUCTION SITE AND LEGALLY
/ f 1 �V `` CI f TWICE ROOT DIAMETER
EXISTING SOIL
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3j - -- �7 V, , �� / DISPOSED OF OFF SITE.
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- Y. _A V '" `P - -� ` - --- ------ / / i - 6. CONTRACTOR SHALL AT AL- TIMES MAINTAIN ADEQUATE SAFETY MEASURES, ACTIVITIES, AND BARRICADES FOR THE
\ �'
- r -- --- --- - -- '1 �� T E � R J--'`t L P LA N J � T DETAIL PROTECTION OF ALL PERSONS ON OR ABOUT THE LOCATION OF THE SITE,
--- -�-- r ,�_ _ ---------- ---- � NTS ?. GRADE TO ELEVATIONS AND DIMENSIONS SHOWN ON DRAWINGS, ELEVATIONAL GRADING TOLERANCE IS ±OA FT,
I
\ 4 `� „ 85 NO GRADING IS TO OCCUR ;N THE DEEP POOL AREAS BEYOND THE SPECIFIED GRADING LIMITS,
EX, C:%. _, 24 / DEEP POOL
RIPRAP OUTLET PRO TET TT ����-_ __ �,O�'���T 'T PF'ESSURE PIPE % � TOP EL. �. '. � �' ' �o� 1
FT
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INSTALLED PER DETAIL ON / BOTTOM EL. 4,3 . -� - TOPSOIL TO BE ADDED TO TOP OF WETLAND SHELF IS TO MEET CRITERIA SPECIFIED BELOW.
" 4� -- Z. TOPSOIL SHALL BE WELL f,4 XED, FREE OF TRASH AND DEBRIS, UNCOMPACTED, AND VOID OF LARGE STONES (>2
� THIS SHEET -_
' � - / -� INCHES) AND WOODY MATE:PIAL (>3 INCHES).
' T `V TT \ WETLAND PLAN V V V 3. TOPSOIL SHALL MEET THE "OLLOWING SPECIFICATIONS:
L/ SOIL TYPE: CLAY < 60%, SAND G 80%, SILT < 60%
SCALE = 1 = 20` ORGANIC CONTENT: 5- %
P-I: 20<50
pH: 6.0-7,0
J TT V V AT R WETLAND 1 f� T T T ( ( T L1 l 4, IN THE EVENT THAT SELEC-ED TOPSOIL DOES NOT MEET SPECIFICATION LISTED ABOVE, SOIL CAN BE AMENDED BY
ADDITION OF APPROPRIATE MATERIALS (MASON SAND OR MATURE STABLE COMPOST, OR LIME).
DEEP POOL ZONE: ALLOWABLE PLANT Sf =..CIES 5 UPON PLACEMENT OF TOP`s')IL, AREA SHOULD BE LIGHTLY COMPACTED TO ENSURE STABILIZATION OF MATERIAL,
DEPTH RANGE ---
SPACING 6. EXCESSIVE TRAFFICKING Of EQUIPMENT OVER WETLAND PLANTING AREAS SHOULD BE AVOIDED,
COMMON NAME BOTANICAL NAME (INCHES BELOW QUANTITY PERCENTAGE SIZE
NORMAL POOL) (pC., FT)
SPATTERDOCK NUPHAR POLYESPALUM 6-16 5
gi -_ MINIMUM DEPTH OF TOPSO SHOULD BE 12 INCHES,
76 33� 2 v' PLUG (MIN)
FRAGRANT WHITE LILY NYMPHAEA LUTEA 6-16 5 78 33% 1�2_N PLUG (MIN)
EX. HDPE FLAT ROOF
-, \. GRADE TO ELEVATIONS AN(" DIMENSIONS SHOWN ON DRAWINGS. GRADED ELEVATIONAL TOLERANCE SHALL BE ±0.1 FT.
AMERICAN LOTUS NELUMBO LUTEA 6 16 5 76 33% IN PLUG (MIN) TRASH RACK TO REMAIN
\ 2. TOPSOIL MATERIAL SHALL SE APPROVED BY ENGINEER PRIOR TO USE BASED ON SOIL PROPERTY TEST SUBMITTALS
THAT INCLUDE STANDARD 7ST METHOD FOR PARTICLE-SIZE ANALYSIS (ASTM D422), PARTICLE SIZE ANALYSIS OF
-- . /
SHALLOW WATER ZONE: ALLOWABLE PLANT � �� II Tn I I Ili I 1
I TI L: �( ��' J TVr SOILS (AASHTO T6S}p AND IGQA SOIL ANALYSIS.
DEPTH RANGE - - L L B AS P 1
SPACING ❑� �� _� ,l `STALL FINAL COVER IN ACCORDANCE WITH PERMANENT SEEDING SPECIFICATIONS WHERE APPLICABLE.
COMMON NAME BOTANICAL NAME (INCHES BELOW (O.C„ FT) QUANTITY PERCENTAGE E __. _ __
- -
NORMAL POOL} I NEW 12" WIDE X 7.44" TALL RISER OPENING
PINT
ARROW ARUM PELTANDRA VIRGINICA 0-6 2.0 196 10% }
I INV. EL, 440.00 1 SIDE CT
PLUG (MIN} { (CONTRACTOR SHALL REMOVE 2 VERTICAL T T
I PICKERELWEED PONTEDERIA CORDATA 0-6 2•® 1g6 10% L �
PARE OF MASONRY BRICK
_ 0 19 10% � ROOT C155 } A C A h
I LQfiI �LI� d T
DUCK POTATO SAGI1°TAR A
--. Z
1 I OPENING
10,O �.
I TRASH SN RACK SLED TO � O ._, -NG '
r- ` (
..WITH A ,
TUS P C G MIN I SC H`OENO LE .� N PLUG }
196 (
0 6
2.0 I v�./
CD CJ }
BULRUSH
E `
BULR ELGVd STEM �; 9 C7 SOFT �}
MONTANI
TABERNAE F
_ ;- NEW .O LOW FLOW ORIFICE EL. 439.00 LN��J!-��__,_ _
ACORUS CALAMUS 0-6 2.0 196 10% BARE ROOT
SWEETFLAG - - _ EX, BRICK AND MORTAR � WITH TURNED-DOWN OINN PVC ELBOW �wElCliE'�.
10% BARE ROOT 4.0 000
THREE WAY SEDGE DULICHIUM ARUNDINACEUM 0-6 2.0 196 RISER BOX I:
-- TO HAVE 2.2 'F HOLE DRILLED IN OAP CT� S GREAT
- {
LUG (MIN)
SPIKERUSH ELEOCHAR(S OBTUSA 0-6 2.0 196 10% 2 "� P I �--^�
10% - , P',_UG MIN � T T d
SOUTHERN BLUE FLAG IRIS IRIS VIRGINICA 0-6 2.0 196 _-� ( ) REMOVE EXISTING UNDERDRAIN
AND GROUT :MOLE � 1 .
'vI PLUG � -
LIZARD'S TAIL SAURURUS CERNUUS 0-6 .0 196 10% v (MIN} j
SOFT RUSH JUNCOS EFFUSUS 0-6 2,O 196 10% 2 N PLUG (MIN) -
-- - / / I FILL WITH GROUT C VIEW
SHALLOW LAND ZONE: ALLOWABLE PLANT "PECIES SIDE \ - � 1 BOTTOM EL.=434.33' CONCRETE ENDWALL FOR
DEPTH RANGE SPACING
FT} 24 ' PIPE PER
(INCHES ABOVE
COMMON NAME BOTANICAL NAME CING QUANTITY PERCENTAGE SIZE
T NCDOT CLAD J
NORMAL POOL}
°� � w< NCDOT DETAIL ,�3�.�a -
Al
SWAMP MILKWEED ASCLEPIAS INCARNATA 0-12 2.0 167 9.0% 2 IN PLUG (MIN)
- - - -- ANGLE IRONS:
FRINGED SEDGE CAREX CRINITA 0--12 2:0 167 9.0% PLUG (MIN} 7.0' 4" X 4" X 5/8" X 4' LONG ---- FLOW - 12'-
GREAT BLADDER SEDGE CAREX INTUMESCENS 0-12 2.0 167 9,0% 2 IN PLUG (MIN) TYPICAL EACH SIDE
° T
HOP SEDGE CAREX LUPULINA 0-12 2.0 167 9.0% IN PUG (MIN)
FASTENERS: � �_° ' 22„
SHALLOW SEDGE CAREX LURIDA 0--12 2.0 167 9.0% 7 PLUG (MIN) EX. 2 CONCRETE
- - `
1" 0 EXPANSION ANCHORS
PRESSURE PIPE �_
SCARLET ROSE MALLOW HIBISCUS COCCINEUS 0--12 .0 167 9.0% :' N PLUG (MIN) C� " O.C.
INV.- 434, TIC l Y
ROSE MALLOW HIBISCUS MOSCHEUTOS 0--12 .Q 167 9.0% 7 PUG (MIN) (AS-BUILT)
FS-2 FILTER STONE
SPIDER LILY HYMENOCALLIS EULAE 0-12 2.0 167 9,0% � IN PLUG (MIN)
SECTION A-A
SWAMP LILY CRINUM ERUBESCENS 0--12 2,0 167 9.0% U PLUG (MIN)
CARDINAL FLOWER LOBELIA
CARDINALIS 0-12 .0 167 9,0% _ 2_^ p!UG (M)N} T I LE SPILLWAY
I P A P OUTLET PROTECTION
SWAMP SUNFLOWER
ANGUSTIFOLIUS HELIANTHUS 0-12 2.0 167 9.0% 12 N PLUG (MIN} SCALE = 1 g: = Zp
N.T.S.
3
SEAL SEAL DATE: FEBRUARY 8, 2019 SALE M&c FILE NUMBER
BRIAR CHAPEL--
\t���ttlllrrlrlf�rIVICE PRO]. # 0735-014
t� GRANITE MILL NFIOW&CUED „' WETLAND
DRAWN 35S DRAWING NUMBER
CA
HORIZONTAL:
4e�
DESIGNED Bs AS NOTED
_ - NORTH CAROLINA
CHATHAM VERTICAL
AL T CHECKED GCA
_ = i 0634 _ 1730 Varsity Drive, Sulu 00
_ _
Raleigh, North Carolina 27606
__-- 1 BRIAR CHAPEL PROJ. NIGR. CHS N/A
Phone: (919)233- 091, Fax: ( 19)233-R031
F-122
TT ,� STATUS: REVISION
1 BIORETENTION AREA REDESIGN-STORMWATER WETLAND 2619 J2:,S ✓! (N \��
REV.NO. DESCRIPTIONS DATE 4 NewlandCOMMUNITIES NOT FOR 7777�11ttilf ���
CONSTRUCTION
REVISIONS www.mckimcreed.com