HomeMy WebLinkAbout20090544 Ver 1_More Info Received_2009062601I- 0544
LEONARD S. RINDNER, PLLC
Environmental Planning Consultant 3714 Spokeshave Lane
Professional Wetland Scientist Matthews, NC 28105
Land Planning (704) 904-2277
June 25, 2009
Ms. Cyndi Karoly/Mr. Ian McMillan
NCDENR - Division of Water Quality
2321 Crabtree Boulevard, Suite 250
Raleigh, NC 27604
PR@Lr9_"0W2 0,
JUN 2, 6 2009
Mr. Alan Johnson
NCDENR Mooresville Regional Office
610 East Center Street, Suite 301
Mooresville, NC 28115
WETLANDS AND TORMWA WATER-QUALITY BRANCH
Re: Silver Landing Transportation Center - DWO 09-0544 - REQUEST FOR
MORE INFORMATION RESPONSE
Dear Madame and Sirs:
On behalf of my client, Ms. Lorin Stiefel of Davidland, LLC, this letter is in response to
your request for a conceptual stormwater plan for the above referenced project.
The information includes a detailed conceptual stormwater management plan prepared by
John R. McAdams Company, Engineers/Planners/Surveyors, in Charlotte, NC, that
includes the followinu as requested.
a. A depiction of the drainage areas on the site.
b. An estimation of the percentage imperviousness associated with each of the
drainage areas.
c. A calculation of the water quality volume associated with each drainage
area.
d. A depiction of a proposed BMP (state the type of BMP you plan to use) on
the site plan that is correctly sized based on the water quality volume.
In addition, the project site is subject to the City of Charlotte's state delegated Stormwater
Program that meets the requirements of Phase II NPDES stormwater program. This is
applied through their Post Construction Control Ordinance (PCCO). A grading permit
will not be issued by the City until the development plans; including the stormwater
management plans are approved. A Certificate of Occupancy will not be issued until the
Stormwater Management Plan is approved and implemented as approved. The City of
Concord will require the 404/401 to be issued prior to approving the plans.
The City of Charlotte requires a very detailed development and engineering plans. This
would require a significant "at risk" investment in the complex architectural plans,
engineering plans, and substantial application fees not knowing formally from the USACE,
NCDENR, and/or other agencies if the permitting process will result in an approval. This
is especially problematic during the current economic conditions. It is for all practical
purposes impossible for the wetlands and streams to be impacted or for a building to be
occupied without the City of Charlotte approval of the Stormwater Management Plan.
Therefore we are requesting that the 401 Water Quality Certification be issued with the
following Additional Conditions:
a) An approval letter from the City of Charlotte and at least one copy of the approved
SMP, including plan details, calculations and other supporting information must be
submitted prior to any approved impacts to streams and/or wetlands.
b) The stormwater plan must be implemented in accordance with the approved plans
prior to occupancy of any permanent buildings.
It is very important to note that the developer, engineers, and planners have no predictable
way of accurately predicting the time frame for the review of the comprehensive
development plans to obtain approval once the plans are submitted to the City. Besides
stormwater other planning and complicated design issues must be included in a submittal
to the City to be a complete submittal (i.e. site plan review and zoning compliance;
sedimentation erosion control; utilities; driveway permits; traffic and circulation issues;
general construction details; landscaping; etc.) to be considered a complete submittal.
Since the project is subject to strict enforcement of the PCCO by the City, and approvals
will not be issued without the 404/401 there is no risk to the State that the buildings can
be occupied without the stormwater plan being implemented. Therefore the NCDENR
should allow the time necessary to submit the approval letter and plans from the City of
Charlotte to NCDENR or include language that allows for additional time to be requested
if needed.
We would appreciate your consideration of approving the 401 Water Quality Certification
with Additional Conditions based on the additional information provided in this letter.
Please on ct me?f you have any questions. Thank you for your consideration.
Environmental Planning Consultant
Professional Wetland Scientist
Cc: Ms. Lorin Stiefel - Davidland, LLC
Steve Chapin - USACE
2
. Y;\Projects\IBC\IBC-08030, Silver Landing Phase 2, InterCon\Land\Construction Drawings\Current drawings\WETLANDS EXHIBIT.dwg, 5/11 /2009 10:50:33 AM, m;
?p WEST OLJ? /??
8??? RD
PHASE 1
(UNDER CONSTRUCTION) PHASE
11
w _
VICINITY MAP
N.T.S.
pm,or m ec-8030 SILVER LANDING PROJECT J1 THE JOHN R. McADAMS
momm IBC06030-VM STffMZ C? ROAD COMPANY, INC.
SCAM CHAIUA=, NORTH CAROUNA mmunw/rrumm/m mmis
6701 CM M 9W sorts ¢06
CUXMM WWCANOLWA 2WW
DAM 05-11-2009 VICINI'TY' MAP (7%) T7-0so0
Y:\Projects\lBC\IBC-08030, Silver Landing Phase 2, InterConTand\Construction Drawings\Current drawings\VVETLANDS EXNIBILdwg, 5/11/2009 3:16:50 PK ma,
® IBC-8030 SILVER LANDING
PROJECT THE JOHN R. McADAMS
C08030-PO STEELE CREEK ROAD COMPANY, INC.
ENGINEERS/PLANNERS/SURVEYORS
CHARLO=, NORTH CAROLINA
8701 CARUn ROAD, SUITE 205 CHARLO 5-11-20(19 PHASE 1 SITE PLAN (704) 527-080NORTH 0 CAROLINA 28228
® PRcwj> " IBC-8030 SILVER LANDING PROJECT J1 THE JOHN R. McADAMS
p"C"A'"B' IBC08030-PO STEELE CREEK ROAD COMPANY, INC.
SCALE: CHARLOTTE, NORTH CAROLINA ENGINEERS/PLANNERS/SURVEYORS
9 6701 CARMEL ROAD, SUITE 205
? Wm: 05-11-2009 PHASE 2 SITE PLANS (704)527-OBOO?H CAROLINA 28226
Y:1Projects\I13C\IBC-08030, Silver Landing Phase 2, lnterConlLand\Constructlon Drawings\Current drawings\WETLANDS EXHIBIT.dwg, 5/11/2009 3:24:36 PM, ma,
YAProjects\IBC\IBC-08030, Silver Landing Phase 2, InterCon\Lano\Construction Drawings\Current drawinys\2009-06-19 RTP Site plan exhibit.dwy, 6/19/2009 12:5;
t ?y
It
j
9
}
.. r - -
%
ti ?1
r
%
1++
A
NN "0
,? ,?, ?C It ?! y, (? ,??,;It I ,?((i I11. , _ ? ? -?•...-`•???vti?` ?? ?? ? , 1 ? ? ? i t ? ?, r, i
/ f??'?? ?"1't ?? + ????t?,tttl+lu?tvt+tv"wv?' ?, ?? t? ???? ;,? ? .- ?,? ti? ? ? ?
r? + \t v r f- - ??? l ` r I / t
lt1l+i ttilll\x tl
?1 fir` ?l / ? Ili+ ?tt> t tl ? irJd¢,ii? I ?? vet tt? t1
1 i? 1 ?? _ (- + 1 !It 4??tjjt !P
f f ? ??r? ,t 1/1141ti1il' , 111111 !)+
r!lll?lt'? it+1 ! trf 4It 1 1 ?? r?? f
r 1 1 lXz t+/r/rr+?i,?r??,l/n1f1+1+111+/, t t 1 ?t l 1??
lilt llli?u?u/1?1(r<<rEr+it l t ?. `?? (11 ?? 111 ?? _? , , ??
it N11
Iff ff /11
t ?
t I 11 ti+lllt\\
a.
V/j?l?ll ,Z
j,
,Ill`
,
® P'?'?'' d? IBC-8030
SILVER LANDING PROJECT
THE JOHN R. MCADAMS
nM r1Le"Ax1e: WETLANDS EX. MELE CREEK ROAD COMPANY, INC.
0 SCAM 1 °a 300' CHARLOTTE, NORM CAROLINA ENGINEERSVEYORS
PLANNERS/SUR
8701 CARME
L ROAD, SUITE 205
p} DATE: 06-19-2009 DRAINAGE AREA MAP (70) 527E,0B00 I[ CAROLINA 28228
"
:g
sp 'g - - - 'Y
PV" a P? C.'2"' - ? PR_. a 111
a, _
`
?
nro
ay
j ?s
} Er P
! u e2uz
4 `0:6•x(
t y? P
t ( 4
RES 7??=
IRK
?'
N ( R ? X
I L " "
I ? I
? ? L. J ?• ?y/ l M ..?
??/ A p ?.rx" ",. -gar l3 ? ?'g '?-'°
\ hl""
g2g2 ?/ ?
?I 9N
?yU
a
a
04F)
AzE R?9p 4 \? , r \' lE RoADI
wQ ?? Ida ?? --
I
\` I
I
a kl r.
? f e
? u 1 I
i H F - 'q" t2 5
v s f z
, -if cFEz X44 ? ?.; pa0 \ R I ?..
m1, He 3X
o EF j `.. 'n
I C c 3 i C.
^ 4F
T pp
., e
= C
Y? z
C)
a a
- t x z
u
N SILVER LANDING - PHASE I
CHARLOTTE, NORM CNiOGRA
GRADING PLAN ^Yr?, '
uenl.one. noH' x .HUU ...n. °'
-
? >.o-. pn u?•
aw e••. 117
,'fib
Y? •
Qh
a
.?.(?31 THE 10H v I: hIcADAMS
contlA. IN C.
exr, nvra /vY n e a/ x;
n?u CP. ITf
RxiH I YYI kn .IN.Y 8220
hwlu?z>-nH
Y Rs Y RIME ss» m • Y s YN a o9?§$ s aw ?, xY?- gP Yi?aaP 1c•. ?
g14" gNy$N" 19
Iaa a %. 1 , &"` g @€, ?• a_"
?qs° Y
€ 8 ` sam " w.9O €R a ' R9 . 4 §, '4 x R? a -111,
° sg YR s 3 # yR" #?R "w5_F=a?§ @ 3 i a
3 9 € $ a? 3 "s alp q0` r a q R?
€ 2 ' ?g$a s ` ad 5g ' :tR 3.
R} all 14, Y $ ? R ? F y Y pp4 ? 2 f- ? ^4 yry'
i"1e @ 3 q C^EB i8 E R F$ Y ET @ F a `23
a ?3 Ili $j" ? = g9s 3's? it ?M F rF FR $R ?P A ¢€ Jill ? ? !
arg¢8 e$ k a s , it - ' h X.0 R $Y ? l ?_? ?; tw1? ? IIIF? Ell
@
s QAR+u{l 4€ s R ro R ill 119gg,R 11 1` ?Q j?$ 1' _1 ? Y Y s
ys?aYa 66 @ 3 oR? $ RE 9}g ue! csa 8 as0??a ??, °x F :?
R €? V a?$ 4€U FR ro? { ' In a R a d
T RF e E E R• gg G$' a3 4 z ?SSa, m 6 9N »
,?' at ?N ? ? ? a a- ti g R Yl? €p xa9? AR g4 ?t„°m^R'? ?? a °?€ $, Y
4 3 $°.`Y 2 '6 g B
§$ai €?s mm 8? sRb R4? 1^€ R lid 1?. " §itF p € $?R Rn3 w?
5 =4€ mYi s n? R R a ?? R> ? s a gp gyg n Y s ' R v a a °?
€i y des; y? E 1 »
?? € ?€ >• ?g9? ? ??n s "? R$s "?F ? ?? ? ??€ R 9??? ,?, ilia
$s{ ors a ?e?
e F4 Y 1$ s 1"i", mx? a? NR A' ?$s ¢?_ € ¢ (3>§ s F?$ R a Y^ R
t ?Y? ? RA? ? i ?Y xg Y^ 17 PX• a s e $ R 6 , ? : a s 7 a?''s € x R e^ a t=¢
:off R? a"? Fi I R > c° $Rrs? s 4?? QaE a F
Ilk fi=x"F `s ;?$$ ?f $a." s ARV 9 z%? ?' 8;a s?=»° aR ?R ov, §$ R ` is A9@ @^° ??
4 n $ s b se ^ § A
s $ to Ye a x ? ,€ _@fa hP` as pa g§?sx6 6 a a s NJ
g @?3 Sid q R E ^ s a
dF',5 s aa?d 1'g A
? § ?R? g F MIT 5R »I a. mac " r s s a
a P- q o, m' 3FaxR€s ?$€ s>RRsg=sYqq• 6$ yk ?; 8` ':-
Y asjj'- q 7? R sm" °?rz?P x» T.
R
€y y %A- ?a€R!I Es? of p7$ r 9F g?q, 7 s " e 4Ra_€ fi 5j,» $c?y€S'
@ td $; @ s s ?ss? $ $?gg g @g # a ?y m "? sx M= ?? ? ?? »
N? 2 R aA8F c g F? ha k€'8 t 2a_?s?x= q[@ ? • F
?$s C ?° t? i ?aFgg _ N? "R 6 A g az$ 8 a RR ? a x a n ?y R4'E? nP=xf?xn? ?? g ? "1?P "
qY b - =c
x@ € 'Pq aR o F ; j- 91 R sg s ?£3 a§ aEaY 9 ?sb F
11 RA
11$RG° F1 iR nu a m i; CS Aw ?9 A k sRa $ ffi R LI AnF RaR Fd6
1. 18
R s? gg? a t?
e I °s N V A! 4
'' { $ ` d? ? s > 'I
Av80 AR}$ i Rg v#y 0 s!_ d - d i_ 55 ?s F? sas £ AY yeE s €4 E s .m Lag y ?N?? g $ ® ?ae8
I if c ? a x 9 a . €Y, 6$ g $ IN, a ??Y
Q? GR 1E 1 nEFF ,> 111 c 2 yN$: g g 5 R a;Y ¦¦aa ? ?
p r q aR R ?$? P• p^" ak, F F ? S? iY FS r, ` A C
k '? s $ R = " s s? °y?o ?sr'g Y EN4y c 0 @ E?w$a 1IRA, x ?q
' YEv ttt ve
= R Rs 9 RasR?'» to a R-
R V5 R U a R t 3?!I °? s A
V$g01 QA ds€? Ms °$ »p a? E?Qv a nUri, 4C
Y €$R RR,S p s €a, ?€
?a?? ?R F a3 @ € ?s 00 0, 1 A 1-11 Nil
"RR R? EE R s? g ¢$P€ eMq."t c ti s$ R c aq'n$ € sjR
@€ € e$ aR 3 g € 4RY Rgz € efl3? €69»?»?- zg€ (?
5 9 a °? ze € Fas R E e t a ,
??l
3 R T g R$ s $ ei R L ? a? E^g ?? gegpp R e 4 R gggg ,g N? s19 R_V $' RfRT
?q= R 3 € '= R X65' 04? {h?6.EL G 0aY 3 .'',', 5$ @9?° r?S€.
RAC € R = s §' g R m Rci?E ? s•a ;? s l?Y£ a ssa€ al
s"?A9? I.F.
Ig@
€?R 6 a§$E 0.? g SFU^ 4?s ?gSAa 2x?j 3q3RS? 44 ?€?Y
9 yG
"d
40
?": §
AR a
P ra
I?
G?s spay Nsa _p
pR SUN
/
3P •-.J / 1 If, l _ _.?? ._-fir _ __- _ _ -
_ sa
;0
F
Ada r? ?,'M.y
R.
E 0r.?jO000C?pGI
C)o
M r
g•: 11 ? 11II
I' Y
J I
'll
it
z ??j? IC ?Rljfl'ill
,i l
3
5
'
PHASE I
SILVER LANDING
DAV.INn U1
w THE JOHN R. McADAMS
INC
COMPANY"
rr
C
!
!
L
g -
CHN0$. NORM CAROSN
6707 - C P,iRtY1E'A It'JAD
(11n[11pT'8, N.- -A 8
-- - -
? /?
1
' .
,
NNCNNS/PLiN-/S(INti-
r
_ N
a
'-"- -'- - -'
SH
'(a ? ?,£
9781 C3RMRL ROAD. SUITE 205
f'R3IUlrTTE, NONY'H CAEUl1NA .'b228
'
- . A ( E Nr FIu:?n pUN _-..-_-_-- °•,+. ..•I IvRAI 52Y-WD°NYII.WRYRNCANAYS.CD
!
1 / \
??ly ??'I ,1 I $n I
-lk
Y_
i
F ..?
? s
ati "1
7+Y 1 \
z_
h
SILVER LANDING - PHASE I
o
DAVIDLAND L
FANYIFF
"t"-- THE JOHN R. McADAMS
COMPANY, INC.
yyy Y z R CHAPIDM, NORIR CARDLWA +.xAFUVrrF N°Frx CAFOUnA eE'.I -_- - '
'? Yy FVU[NFL'R4/?LWNYR:/suFYFY°Fs
C ? ,,; ? ? R
s ___..___ b
?R ' Ft01 CAFYNL YUAU, 3UITI4 LUS
v $ ? __--_ _ _ __-____
_-____ -_-._ - N? cISFL°nF. NcFtF r.AFauNA z"zzo
R1 POSf•DEVELOPMENT WATERSHED MAP W 14?tU"UC FFF.tU"NNY::AUi145.CCH
f8
1'1
p?v r
-A sl
? _
I I ?? ?I I I l l l. _ /
,
1 ,'
i
---
-
r -
,.v
i - -- ?- _??
Jl 41
- 11
r
i
i
-
a
3f ?1:
i r.
a?
-
ASE I
AYlJLANU LI
C THE JOHN R. MCADAMS
L
9 _ d SILVER LANDING -PH
.
70
-- ------
s,
COMPANY INC.
?!j °
'
° p CILAI&O MOMCAMUMA CY.ULL'TMR. N°Rt6 LANn1lNA [a2 _- __ "3 . -?s /I'?NXx'/"-1 FYEYOIti'
GtX
BV
F ffE 2
i N?
2R ?} 4 Fki -
-- _.... ??
??f?? C Y
R
? ¢ xU
;NAALOTI'8. xoP.IN Ro??ne °zzn
z°FI szr-mmn ?n
r°nvouc Unws
cnR
O 3 PHEDEVEWPMENP WA -PS ED MAP „ ..,. .
.
?
Silver Landing Stormwater Management Facility Design J.C. Diaz, PE
IBC-08020 Stage-Storage 5/l/2009
Average Incremental Accumulated Estimated
Contour Contour Contour Contour Stage
Contour Stage Area Area Volume Volume w/ S-S Fxn
(feet) (feet) (SF) (SF) (CF) (CF) (feet)
710.00 0.0 23927
711.00 1.0 29454 26691 26691 26691 1.00
712.00 2.0 32669 31062 31062 57752 1.99
713.00 3.0 34995 33832 33832 91584 2.99
714.00 4.0 37371 36183 36183 127767 4.02
Storage vs. Stage
140000
120000 y=26,588.8241x1.1284
R2 = 0
9999
100000 .
U 80000
w
`
60000
o
N 40000
20000
0
0.0 1.0 2.0 3.0 4.0 5.0
Stage (feet)
I Ks = 26,588.8 f
b = 1.12841
X:\Projects\IBC\IBC-08020\Storm\Construction Drawings\Design Files\Stormwater Management Facility Design Page I
Silver Landing Stormwater Management Facility Design J.C. Diaz, PE
IBC-08020 Water Quality Volume 5/1/2009
FEE ?' u =
The runoff to the pond for the 1" storm detention requirement is calculated using the Schueler Method in accordance with
the Charlotte-Mecklenburg BMP Design Manual, (April 2008).
WQ v = (P) (R v) (A)/12
WQv = water quality volume (in acre-ft)
Rv = 0.05+0.009(1) where I is percent impervious cover
A = area in acres
P = rainfall (in inches)
Input data:
Impervious area = 7.35 acres
Total area, A = 10.94 acres
Percent impervious cover, I = 67.2 %
Rainfall, P = 1 inches
Calculated values.
Rv = 0.65
WQv = 0.60 acre-ft
Therefore, total runoff from precipitation in question = 25998 CF
This amount of runoff must be stored in the pond above and be released in a period of two (2) to five (5) days, by an
inverted PVC siphon, the invert end of which is set at permanent pool elevation.
Normal pool depth (above invert) = 0.00 feet
Storage provided at nPrrrtanent nnnl depth = 0 CF (calculated)
Total storage required for normal + storage pool = 25998 CF
Ks = 26588.8
b = 1.1284
Invert Elevation= 710.00
Stage (above invert) associated with this storage = 0.98 feet
Therefore, depth required above normal pool for storm storage = 0.98 feet
11.76 inches
Therefore set crest of principal spillway at stage = 2.00 feet
and EL = 712.00 feet
At principal spillway crest, storm pool storage provided = 58127 CF
X:\Prgiects\IBC\IBC-08020\Storm\Construction Drawings\Design Fi les\Storm water Management Facility Design Page 5
Silver Landing Stormwater Management Facility Design J.C. Diaz, PE
IBC-08020 Surface Area 6/23/2009
Impervious Area = 7.35 acres
Drainage Area = 10.94 acres
% Impervious= 67%
Average Depth = Accumulated Contour Volume / Surface Area
Average Depth = 3.0 ft.
Per NCDENR "Stormwater Best Management Practices", the required SA/DA ratio --i
3.0 3.0 4.0
Lower Boundary - 60.0 2.40 2.03
Site % impervious - 67.2 2.74 2.74 2.30
Upper Boundary - 70.0 2.88 2.40
Area Required = 13081 sq.ft.
Area Provided = 23927 s .ft.
X:\Proiects\IBC\IBC-08020\Storm\Construction Drawings\Design Fi les\Storm water Management Facility Design Page I
y-..\Protectsll BCVBC-08030. SOW., Landing Phase 2, InterConlLandlConsVUCtion DrawingslCurrent drawingsVBC8030-G2.dwg, 61222009 10:15:53 AM, mayo, 25.4:2.19854
??
?T -a
?% ?I?4 b ? d 1-•..
C,.
?j
,
fb f t „I i ??
hd ?' tai
?
j?
4
4,,
rh?
'`
?_
? v 71 ??
rF
1
?- 'rl? -?- ? 1 III
f E
0 q+
l
al
3
? ga8v 9 ? ? ? ? ? ? 4 E
IT g ?
sti ?t
III usI I ' : ? ?
Hi;js I ?? ? • ?
i1? I I
'? sf;I I a t
fit •t; 1 ? I I ?
s g g
Ey?
•?i
m
Q 6 °f? °'®1°' THE JOHN R
McADAMS
II.UER LANDING - PHASE II
- .
®
COMPANY, INC.
>5 x CRAMOM MOM CiROLVA wmn...rRr. r..aa. wro ,_
?F?}' mcom.y.umm/iuxmm.
ml CAM= ?' am m
Ditmum GRADING PUN `•r,..,,, Itul esr-aeoo m 110111XIN^,^•-- M
Silver Landing Ph. 2 Preliminary Stormwater Management Facility Design J.C. Diaz, PE
IBC-08030 Stage-Storage 6/22/2009
Average Incremental Accumulated Estimated
Contour Contour Contour Contour Stage
Contour Stage Area Area Volume Volume w/ S-S Fxn
(feet) (feet) (SF) (SF) (CF) (CF) (feet)
672.50 0.0 38693
673.00 0.5 39565 39129 19565 19565 0.52
674.00 1.5 42220 40893 40893 60457 1.47
675.00 2.5 44931 43576 43576 104033 2.43
676.00 3.5 47698 46315 46315 150347 3.42
677.00 4.5 50522 49110 49110 199457 4.44
678.00 5.5 53403 51963 51963 251420 5.51
679.00 6.5 56340 54872 54872 306291 6.61
680.00 7.5 59334 57837 57837 364128 7.76
Storage vs. Stage
400000
350000 1.0785
Y = 39,926.9330x
300000 R2 = 0.9992
C 250000
U
200000
a
150000
100000
50000
00
,000000,
0 40
0.0 2.0 4.0 6.0 8 .0
I Stage (feet) I
Ks = 39,926.9
b = 1.0785
X:\Projects\IBC\IBC-08030\Storm\Design Files\Preliminary Stormwater Management Facility Design Page 1
Silver Landing Ph. 2 Preliminary Stormwater Management Facility Design J.C. Diaz, PE
IBC-08030 Water Quality Volume 6/22/2009
UMIRM .IT,.
The runoff to the pond for the I" storm detention requirement is calculated using the Schueler Method in accordance with
the Charlotte-Mecklenburg BMP Design Manual, (April 2008).
WQ v = (P) (R v) (A)/12
WQv = water quality volume (in acre-ft)
Rv = 0.05+0.009(1) where I is percent impervious cover
A = area in acres
P = rainfall (in inches)
Input data:
Impervious area = 20.90 acres
Total area, A = 36.20 acres
Percent impervious cover, I = 57.7 %
Rainfall, P = 1 inches
Calculated values:
Rv = 0.57
WQv = 1.72 acre-ft
Therefore, total runoff from precipitation in question = 74851 CF
This amount of runoff must be stored in the pond above and be released in a period of two (2) to five (5) days, by an
inverted PVC siphon, the invert end of which is set at permanent pool elevation.
Normal pool depth (above invert) = 0.00 feet
Storaee provided at permanent pool depth = 0 CF (calculated)
Total storage required for normal + storage pool = 74851 CF
Ks = 39926.9
b = 1.0785
Invert Elevation= 672.50
Stage (above invert) associated with this storage = 1.79 feet
Therefore, depth required above normal pool for storm storage = 1.79 feet
21.49 inches
Therefore set crest of principal spillway at stage = 2.00 feet
and EL = 674.50 feet
At principal spillway crest, storm pool storage provided = 84319 CF
X:\Projects\IBC\IBC-08030\Storm\Design FilesTreliminary Stormwater Management Facility Design Page 2
Silver Landing Ph. 2 Preliminary Stormwater Management Facility Design J.C. Diaz, PE
IBC-08030 Surface Area 6/22/2009
Impervious Area = 20.90 acres
Drainage Area = 36.20 acres
% Impervious= 58%
Average Depth = Accumulated Contour Volume / Surface Area
Average Depth = 3.0 ft. assume minimum average depth
Per NCDENR "Stormwater Best Management Practices", the required SA/DA ratio -
3.0 3.0 4.0
Lower Boundary -• 50.0 2.06 1.73
Site % impervious -> 57.7 2.32 2.32 1.96
Upper Boundary - 60.0 2.40 2.03
Area Required = 36630 sq.ft.
Area Provided = 38693 s .ft.
X:\Projects\IBC\IBC-08030\Storm\Design Files\Preliminary Stormwater Management Facility Design Page 3
r I v .P F? §!e
g MS :,
)N 8V 3,q J3 SiSHN j - aS. i ; 5 .p,f ?_ 6 y
9 { y r LL i5 a ? e?.
3
' I
..
f I? AJ ~
- ..'.
i
Y
•
I .UZ3 .A: B ?
Y ?
FJi?A? \
\ 1
,.? 5 y
?
? I
II I
r
1 1 - Sao a
y ig S
I _
d y
aE.S k E ti E Y 5 ,? I I
ITT to S?x?s? f
ywy
5 TdR -{ Q¢k
a r
>, "?' II s I I11
BIT
.? '
00 &
"AV a
Hjl
1 .P _. -
Y
- - i?, -i-'?•??. /? ? _ .-< 11 ' .
an
{7 i3
I i f [ 4 ?!F ^I:;
-01 ;L
c 'F tr ?L • w SIR Ilia
tam
? I f
, C
45
- 1 _
a e
Al'
AREP NCDENR
North Carolina Department of Environment and Natural Resources
Division of Water Quality
Beverly Eaves Perdue Coleen H. Sullins Dee Freeman
Governer Director Secretary
June 11, 2009
DWQ Project # 09-0544
Mecklenburg County
CERTIFIED MAIL: RETURN RECEIPT REQUESTED
Ms. Lorin Stiefel
DavidLand, LLC
6707 Fairview Road, No. C
Charlotte, NC 28210-3354
Subject Property: Silver Landing Transportation Center
Ut to Coffey Creek [030835, 11-137-4, CJ
REQUEST FOR MORE INFORMATION
Dear Ms. Stiefel:
On May 12, 2009, the Division of Water Quality (DWQ) received your application dated May 11, 2009,
to fill or otherwise temporarily impact 873 linear feet of intermittent stream to construct proposed
transportation center at the site. The DWQ has determined that your application was incomplete and/or
provided inaccurate information as discussed below. The DWQ will require additional information in
order to process your application to impact protected wetlands and/or streams on the subject property.
Therefore, unless we receive _Five copies of the additional information requested below, we will place this
project on hold as incomplete until we receive this additional information. If we do not receive the
requested information, your project will be formally returned as incomplete. Please provide the following
information so that we may continue to review your project.
Additional Information Requested:
1, Please provide a conceptual stormwater management plan for the project that includes the
following:
a. A depiction of the drainage areas on the site.
h. An estimation of the percentage imperviousness associated with each of the drainage
areas.
c, A calculation of the water quality volume associated with each drainage area,
d. A depiction of a proposed BMP (state the type of BMP you plan to use) on the site plan
that is correctly sized based on the water quality volume.
Please submit this information within 30 calendar days of the date of this letter. If we do not receive this
requested information within 30 calendar days of the date of this letter, your project will be withdrawn and
you will need to reapply with a new application and a new fee.
Thine letter only addresses the application review and does not authorize any impacts to wetlands, waters or
protected buffers. Please be aware that any impacts requested within your application are not authorized (at
401(H x0f ReVra PearmisMrg7 Unit
1W Wito carsV. ROOD, tJ" CorOm 2769 165D
Ltscow 7321 Or 0W. tts"h, Mom Cxohms 7765(9
Plow 910=7331766 t FAX 319433
rnt~ 1VO Rare *vow, r5sfrnmidemw
One
NorthCarolina
J1 WMAWAY
a, froc,m' noly?AM"*;*&rY E
DavidLatnd, I I(I
Page 2 of 2
little 11, 2009
this time) by the DWQ. Please call Ms. Cyndi Karoly or Mr. kin McMillan at 919-733-1786 if you have
any questions regarding or would like to set up a meeting to discuss this matter.
Sincerel , x-,-,
r
XCY ndi Karoly, Supervisor
Oversight/Express Review Permitting Unit
CBK/gym
cc: Alan Johnson, DWQ Mooresville Regional Office
USAGE Asheville Regulatory Field Office
Filc Copy
1>cn Rindner, 3714 Spokeshave Lane, Matthcws, NC 28105
hicname? 090544SilverLandingTransportationt'enter(Mecklenbur),)on Hold