20090308 Ver 1_Emails_20090720

Lespinasse, Poll
From: Hinson, Isaac ([e-mail]. nc.us]
Sent: Monday, July 20, 2009 8:31 AM
To: Lespinasse, Polly
Subject: RE: Freedom Drive Widening Project (USACE Action ID SAW-200900443, DWQ #09-0308),
revised mitigation proposal
Thanks Polly! Steve Chapin actuallyjust responded and said that he will require a new PCN with cover letter describing
the change. Please let me know if you need anything else from me. Again, sorry for all the confusion.
Isaac
.._ .. __.., _ _....... .._.. _._
From. Lespinasse, Polly [mailto:polly.lespinasse@ncdenr gov]
Sent: Monday, July 20, 2009 8:26 AM
To: Hinson, Isaac
Subject: RE: Freedom Drive Widening Project (USACE Action ID SAW-200900443, DWQ #09-0308), revised mitigation
proposal
Thanks for checking into this Isaac. I am hoping to have the WQC finalized and out tomorrow.
From: Hinson, Isaac [mailto:[e-mail]]
Sent: Friday, July 17, 2009 2:17 PM
To: Lespinasse, Polly; 'Chapin, Stephen SAW'
Cc: 'Johnson, A. Chris'; Russell, Thomas (ENG)
Subject: Freedom Drive Widening Project (USACE Action ID SAW-200900443, DWQ #09-0308), revised mitigation
proposal
Polly,
Well, I figured out that easements have already been obtained and the 80 LF pipe will remain and not be daylighted. So
this puts us at having to mitigate for 80 additional linear feet of impacts to Stream B (from the proposal in the PCN). Per
our permit submittal and previous correspondence with both agencies, it was proposed that we would purchase
mitigation credits for impacts to this channel (Perennial Stream B) at a 1:1 ratio. Fortunately, EEP issued made more
than enough (920) credits available for purchase. Please see the PCN and cover report for the rationale for mitigation
requirements and ratios. Below is the proposed revised breakdown of the in-lieu fee payment to NCEEP for project
impacts.
Perennial Stream A: 270 LF impacts at 1.5 to 1 mitigation ratio = 405 credits to be purchased from NCEEP.
Perennial Stream B: 298 LF impacts at 1 to 1 mitigation ratio = 298 credits to be purchased from NCEEP. (This is an
increase in 80 credits from the previously proposed purchase of 218 credits).
Total REVISED credit purchase = 703 credits.
Please let me know if you need something written to document this revised permit request.
STEVE- Let me know if you need anything else or if you can issue a revised NWP based on this email.
Sorry for the confusion. Please let me know if I need to do anything else to finalize the issuance of the 401/404
authorizations.
Isaac Hinson, PINS
Wetland Specialist
Charlotte-Mecklenburg Storm Water Services
[e-mail]
Office: 704-336-4495
Mobile: [phone]
Fax: [phone]
From: Lespinasse, Polly [mailto:[e-mail]]
Sent: Friday, July 17, 2009 9:06 AM
To: Hinson, Isaac
Subject: RE: Freedom Drive
Thanks Isaac.
I will wait to get confirmation from you regarding the 80 If before I write the permit.
Have a good weekend
From: Hinson, Isaac [[e-mail]]
Sent: Friday, July 17, 2009 8:12 AM
To: Lespinasse, Polly
Cc: Hinson, Isaac
Subject: RE: Freedom Drive
Polly,
Thanks for your continued attention to this project. Below (in red) are my answers to your comments. Please let me
know if you need anything else.
Isaac Hinson, PINS
Charlotte-Mecklenburg Storm Water Services
Desk(704)336-4495
Cell [phone]
From: Lespinasse, Polly [mailto:[e-mail]]
Sent: Wednesday, July 15, 2009 7:53 AM
To: Hinson, Isaac
Subject: Freedom Drive
Isaac,
I am beginning to put the WQC together for this project, but have a question. On Stream B, there is some reference to
80 feet of stream being daylighted (Station 310 to 315) and mitigation credit proposed for it. Version 3 of the plans
indicate that the culvert remains in place and the Summary Table included in the application doesn't indicate the use of
80 feet as mitigation (only shown on the Version 2 information). So, I am unsure whether you are going to leave the 80
ft. culvert as shown on Version 3. If Version 3 is the version we are supposed to use, then I will need a revised plan
showing the removal of the culvert. Version 3 is the version that we are going with (along with the revised benching up
and downstream of the Paw Creek culvert). To my surprise, this version currently does not include daylighting the 80 LF
of currently piped stream (this was apparently abandoned when the road embankment was steepened to avoid channel
impacts), but our engineer is checking with our real estate department to see if it is too late to get this re-included. I will
get in touch with you to let you know ASAP. If not, we may just have to mitigate for this additional LF (I think the EEP
made available more credits than will be necessary).
Also, the PCN application indicates 87 ft. of fill in addition to the culvert and the riprap on Stream B. Can you refresh me
what that impact is for? This is actually 2 distinct impacts. 40 LF of fill is illustrated on Figure 13 and is the result of
extending an existing pipe an re-routing the channel into a newly constructed rip rap channel at the outlet of a new pipe
system. The abandonment/fill of the old channel meander is a direct result of the construction of the new stormwater
outfall and the newly configured localized drainage. The other 47 LF of fill is illustrated in Figure 14 and is the result of
relocating an existing driveway culvert away from the Freedom Drive fill slope. Again, a channel meander will be
abandoned/filled to facilitate the relocation of this culvert and the impacts encompass a newly-created stretch of V-
shaped ditch that will enter the new culvert.
FYI - On future PCN submittals, you can use one form for the stream impacts (i.e., S1 is the first impact site, S2 is the
second impact site). It might save you some time and paper in the future. Also, the construction of floodplain benches
is not considered mitigatable stream impact (since you are either returning the stream to its natural dimension or
preventing an overwidening). That will not apply in this case since you are still providing the extensive amount of riprap
in the channel, but I wanted to let you know.
I will be in the field most of today and tomorrow, but if you get me the additional info. I can get the certification written.
Thanks!
Polly Lespinasse - Polly. Lespinasse ncdenr.eov
Environmental Specialist
North Carolina Dept. of Environment & Natural Resources
Div. of Water Quality
610 E. Center Ave., Suite 301
Mooresville, NC 28115
Ph: 704.663.1699 Fax: [phone]
E-mail correspondence to and from this address may be subject to the North Carolina Public Records Law and may be
disclosed to third parties.
Charlotte-Mecklenburg
STORM
WATER
Services
June 25, 200!
Ms. Polly Lespinasse
NC Department of Natural Resources, DWQ
Mooresville Regional Office
610 East Center Avenue, Suite 301
Mooresville, North Carolina 28115
Charlotte Storm Water Services
600 E. Fourth St., 141 Floor
Charlotte, NC 28202-2844
?V1.J
Dvvf"
•?Ln'VI
Subject: RESPONSE TO COMMENTS/CONCERNS
Pre-Construction Notification Pursuant to Nationwide Permit
No. 14 and Water Quality Certification No. 3704
Freedom Drive Widening Project
DWQ #09-0308, USACE Action ID SAW-2009-00443
Charlotte, North Carolina
Dear Ms. Lespinasse:
The City of Charlotte Storm Water Services (CSWS) is submitting this letter to address
North Carolina Division of Water Quality (NCDWQ) comments for the Freedom Drive
Widening Project as indicated in your letter, dated April 15, 2009 (DWQ #09-0308). The
original Nationwide Permit notification was submitted to the U.S. Army Corps of
Engineers (USACE) and NCDWQ on March 18, 2009. USACE authorization (Action ID
SAW-2009-00443) was issued by Mr. Steve Chapin on April 24, 2009. NCDWQ's
continents and the City of Charlotte's responses are outlined below.
NCDWQ Comment 1: Proposed permanent impacts to Stream A (Paw Creek) total 270
linear feet (If) (1101f feet for double box culvert extension and 1601f for riprap inlet and
outlet protection). The existing structure is a perched, double box culvert. Low or
normal stream flow is currently conveyed through only one of the existing culverts. The
additional, or flood/high flow, culvert contains a sill, which is at an elevation
approximately one (1) foot higher than the existing perched, low flow culvert elevation.
It is DWQ's understanding that the existing double box culvert will be replaced and the
new, larger double box culvert will be properly buried in the streambed in order to correct
the perched pipe condition. DWQ is concerned that the installation of the double culverts
will cause an overwidening of the existing stream. Please provide details on how you
propose to maintain the natural stream dimension.
City of Charlotte Response: The proposed culvert crossing of Stream A (Paw Creek)
will consist of a double 8' (wide) by 12' (tall) box culvert. One box will be buried F
below the bed and the other will be perched 1' to 1.5' above the bed elevation using sills
at the inlet and outlet. In addition, the appropriate channel dimensions immediately up
and downstream of the culvert will be maintained with benches (including rock toe) to
To report drainage problems: 704-336-RAIN http.//stormwater.charmeck.org
WCharloro?Mecklenbvrg Charlotte Storm Water Services
STORM 600 E. Fourth St..1 P, Floor
WATER Charlotte, NC 29202-2844
Services
maintain the 8'-wide base flow channel cross section. These channel modifications are
illustrated in the enclosed X-sectional drawing of the Paw Creek Culvert. The lengths of
the bankfull benches will be minimized to tie in to the existing channel at the most
proximate point where the channel is not artificially overwidened as a result of the
existing culvert. Incorporation of the bankfull benches will not result in additional
channel impacts as these reaches overlap with the proposed rip rap aprons associated with
this culvert (discussed in the response for NCDWQ Comment 2).
NCDWQ Comment 2: The culvert replacement/extension on Stream A proposes 56 If
of riprap at the inlet of the culverts and 104 if of riprap at the outlet of the culverts.
DWQ staff is requesting that additional avoidance and minimization measures be
investigated at this site. Proper culvert burial (as indicated above) should result in
reduced streambed scour and therefore a reduction in the amount of riprap required as
inlet/outlet protection. In addition, the construction of floodplain benches at the inlet and
outlet of the culverts will reduce the amount of stream impact and provide a reduction in
City's stream mitigation costs. Construction of floodplain benches will also maintain the
stream's natural dimension and profile as required (and discussed above).
City of Charlotte Response: Upon further evaluation, The City of Charlotte has
determined that due to the calculated flow velocities, we cannot reduce the proposed rip
rap lengths upstream or downstream of the Paw Creek culvert. These lengths have been
determined to be the absolute minimum stabilization necessary to dissipate water
velocities and adequately protect the culvert and adjacent stream channel. The requested
floodplain benches have been incorporated into the plan and are discussed in the response
to NCDWQ Comment 1.
NCDWQ Comment 3: Provide the proposed slope of the new culverts on Stream A.
City of Charlotte Response: There slope of the proposed double-box culvert on Stream
A is 0.9%.
NCDWQ Comment 4: The application indicates that stream impacts were minimized on
Stream B through the use of 2:1 slopes adjacent to the stream. Discussions while on site
indicate that the fill slopes may be approximately 20 feet above the existing streambank
elevation. Please provide details on how you plan to properly stabilize these slopes in
order to prevent bank erosion or sloughing during and after construction.
City of Charlotte Response: A temporary erosion control mat will be used to establish
vegetation (i.e., grass) and stabilize the road embankment slopes.
To report drainage problems: 704-336-RAIN http://stormwater.charmeck.org
Charlotte-Mecklenburg
STORM 600 Charlotte Services
600 E. Fourth S1., 14°- Floor
WATER Charlotte. NC 29202-2944
Services ?-v-
NCDWQ Comment 5: Please provide details on how you plan to address stormwater
discharges associated with this project. Where possible, stormwater should not be
discharged directly into the stream or onto the streambanks (to prevent erosion).
City of Charlotte Response: Upon receiving comments from NCDWQ, the City of
Charlotte re-evaluated all of the proposed stormwater outfalls. The use of plunge pools
in concert with grass swales was considered in an attempt to allow for some pre-treatment
of stormwater before being discharged to the on-site stream channels. At all locations,
velocities are too high for grass channels and/or there is not enough available area to
incorporate plunge pools. These site constraints are partially due to the fact that
Perennial Stream B flows parallel and immediately adjacent to Freedom Drive. This
proximity has caused the City of Charlotte to increase the slope of the road embankment
to avoid and minimize fill impacts to the channel. Due to these site conditions, there is
no feasible opportunity to discharge stormwater short of the on-site streams. All
proposed stormwater outfalls do include rip rap dissipation measures to prevent erosion
of the receiving stream channels.
Please do not hesitate to contact Isaac Hinson at 704-336-4495 or email at
[e-mail] should you have any questions or further comments regarding
this project.
Sincerely,
-? A',- ?
Isaac Hinson
Wetland Specialist
Charlotte-Mecklenburg Storm Water Services
Desk phone [phone]
[e-mail]
enclosure: X-section of Paw Creek Culvert
cc: Mr. Steve Chapin, U.S. Army Corps of Engineers
File
To report drainage problems: 704-336-RAIN http://stormwater.charmeck.org
I
I
I
I I i
(-A4 W
-
--
-
I
W
ul I
�
_ - _ i
-.
-
.
.ILII •• .
OII
I
i
I
I
j , I I
I
I
i
I
i I
I
r
VI I
,
ol
I
i I
I
O
�
I I
i I
----- —
--r--I
--------
o
C)
--
�_
- -
o
r
I---I
O
I
ty,cn
-
mQ
j
00
00
z m
0-0
1
Z O I i
i
I
I
I
I
- I I
1
I
I
Y.
m o
m I I,
I
-
103u,
10 I
00s
I X
.
W
----
-
r -
�m
I------
----�L
m 00
o
:
I
vl
� I
-
NI
\ O
_-mo
\\_ L
Lp
m
I i
rl_-_
o
I
I
I
I
\
! I
I
i
I
.
II
I
I' II
u' li I 1_ II
! I
I
I i i I cr
1 i
1
1
ul
I
I I
I
I i i
I
IEEE
FREEDOM
ASIA
JCB x0.
6
Y4E
No '• oA>E Br{ �' DEscBlPngvi, ...
Sun S ;.M FI' {.aIR1J Plans PreoorBO By
q b> ;
E}S� +� iii tl• ; A ] b
KyBa6�ay•'g
1
DRIVE
GUBMU FIm'ng
1 r� �'
iJ�i �9(
DAD Eu PAM
LiL
AG
OF
TYPICAL DITCH
PgCVE By
[MIX[D By
NEi RExlxn, <
]01 5. MCGGWCLL ciiC 6LrC DC9
xu oi,E. Dx.x =.x= NI _ _ 36{
ZP�OHE.-
]C
lti
y� Hg
SECTION
AJ-]R6 ,C Lu', ] ] ]6
PnDCDer
Derz
ifi> R�4 ynM;