20141272 Ver 1_More Info Received_20150223

NOIC "I`H CAROLINA
Public Services
401 & Buffer Permitting Unit
Attn: Danny Smith
1617 Mail Service Center
Raleigh, NC 27699 -1617
City of Wilson
P. O. Box 10
Wilson, NC 27894 -0010
February 10, 2015
Subject: Additional Information
Wingate Streambank Stabilization (DWR #14 -1272)
Dear Mr. Smith,
DC�IG
{-t3 2 2015 !
The following letter and attachments are in response to the Request For Additional Information
for the Wingate Streambank Stabilization 401 Water Quality Certification and Riparian Buffer
Authorization.
In this request you state:
"The application does not include justification for the use of hard armoring (i.e.
gabion baskets) at this location on the stream. In other words, why is it not
possible to stabilize this streambank with a less invasive technique. [15A NCAC
02H .0502(g)]"
To answer this we are including information concerning the cause of the erosion, and a timeline
and techniques used for past stabilization efforts at this site that were ineffective.
Cause: This site includes a stream along back property lines of single family residential
development and carries some flow from an upstream commercial area. The drainage area for
this stream is nearly built out. The stream is narrow and during heavy rain events becomes
overwhelmed. These peak flow events combined with erodible soil have caused the stream bed
to incise several feet to its current elevation where the incising has reached a harder clay pan.
Once the stream stopped getting deeper it began naturally widening during each successive
heavy rain event. During some heavy events, this stream has topped its banks.
P. O. BOX 10 * WILSON, NORTH CAROLINA 27894 -0010 * TELEPHONE [phone]
OPERATIONS CENTER * 1800 HERRING AVENUE * FAX [phone]
EQUAL OPPORTUNITY /AFFIRMATIVE ACTION EMPLOYER

For most of the stream, the erosion is minimal as the streambanks are stabilized by existing trees
and shrubbery root systems. At Mr. Hales property (site in consideration), there is a 40 foot
length of streambank that is cleared of vegetation. Mr. Hales has a wooden privacy fence along
the top of the stream bank and inside the fence is lawn with poor establishment of grass. This
area also receives significant surface flow from Mr. Hales front yard, under the fence, and down
the side of the eroding stream bank. Directly opposing this location, the bank includes a tree root
system that is stabilizing the opposing side and deflecting the stream flow in a slight bend into
Mr. Hales bank.
Timeline: Mr. Hales first contacted the City of Wilson about this issue in 2010. Staff was sent
to investigate and found the streambank eroding near and under his fence. (See pictures labeled
2010 Pre - stabilization). The City decided to assist in protecting Mr. Hales yard and fence by
stabilizing the bank (see construction techniques below).
This 1St stabilization effort held for a couple years without complaint from Mr. Hales. In 2013,
Mr. Hales again contacted the City of Wilson about the area eroding again. The previous
installation had failed and the erosion was continuing under his fence.
In November of 2013, the City of Wilson performed a 2nd stabilization effort (construction
techniques below). Approximately one month after installation, the area experienced a heavy
rain event and the stabilization effort began to come loose and slide down the bank and erosion
continued. (see pictures labeled January_2014)
By May of 2014, the stabilization efforts had completely failed and had slid down the bank into
the stream bed causing a narrowing of the stream channel and potentially worsening the erosion
on the bank. (see pictures labeled May_ 2014)
At this time the City of Wilson decided to pursue this permit to use gabion baskets to stabilize
the stream as described in our application.
Since then the area continues to experience heavy flow events and continues to erode. (See
pictures labeled January_2015)
Construction Techniques: For the first stabilization attempt in 2010, the stormwater crew used
10" diameter 10' long coir logs in the affected area. The stream and bank were cleared of any
debris. The first row of coir logs was slightly trenched into the stream bed at the estimate
original bank location and stream width. The area behind this coir log (between the log and
eroded bank) was then backfilled using loose soil material to be sure to fill in all the voids. This
backfill was not tamped or compacted. The coir log was then staked into place with wooden
stakes (see picture). Then the next rows of coir logs were placed on top of the previous rows,
backfilled, and staked as to recreate the original nearly vertical streambank and restoring several
feet of yard that had eroded away with backfilled soil. The area was then seeded with a
contractor mix seed and matted on the top of bank with coconut fiber matting that was trenched
in at the top and stapled. No tacking or live stakes were used.
P. O. BOX 10 * WILSON, NORTH CAROLINA 27894 -0010 * TELEPHONE [phone]
OPERATIONS CENTER * 1800 HERRING AVENUE * FAX [phone]
EQUAL OPPORTUNITY /AFFIRMATIVE ACTION EMPLOYER

The second stabilization attempt in 2013 followed a similar procedure with the same materials.
Prior to work, however, the fence was moved away from the stream bank by approximately 5
feet. Then as in the first installation, the first row of coir logs were placed at the original bank
location and stream width and then backfilled level behind the logs. Then the subsequent rows
were placed on top and slightly stepped back from the previous rows in order to form a stream
bank with a slope of approximately 2' vertical to 1' horizontal. Again the area between the log
wall and the eroded bank was backfilled with soil and the logs were staked with wooden stakes.
The top of bank was also seeded and matted with coconut fiber matting and again stapled. No
tacking or live stakes were used.
Summary: Because this area continues to erode, despite efforts to stabilize the banks using the
less invasive techniques detailed above, the City of Wilson requests to be permitted to use
hardened structures (gabion baskets) to stabilize the banks and stream bed in a more permanent
manner.
We appreciate your timely response and consideration.
Sincerely,
Daryl Norris
Stormwater Environmental Specialist
City of Wilson
252- 296 -3305
dnorriskwilsonnc.org
C: Bryant Bunn, P.E., Engineering Services Director
Barry Parks, Water Resources Director
P. O. BOX 10 * WILSON, NORTH CAROLINA 27894 -0010 * TELEPHONE [phone]
OPERATIONS CENTER * 1800 HERRING AVENUE * FAX [phone]
EQUAL OPPORTUNITY /AFFIRMATIVE ACTION EMPLOYER
1;

V Stabilization Attempt
10" coir logs 10' long -20 logs
Staked in wooden stakes
Coconut fiber matting trenched in at top of bank & stapled
Seeded with contractor mix
No live staking
Trenched in base row logs
Backfilled level behind 1St row
Stacked next row and backfilled
Nearly vertical slope
Repeat to top
2nd Stabilization Attempt
Fence was moved away from creek about 5'
10" coir logs 10' long -30 logs
Staked in wooden stakes
Coconut fiber matting trenched in at top of bank & stapled
Seeded with contractor mix
No live staking
Trenched in base row logs
Backfilled level behind 1St row
Stacked next row then backfilled
About 2 vertical to 1 horizontal
Repeat to top
*Construction information provided by field crew supervisor
Existing Grade
Existing Grade Backfill

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North Carolina Department of Environment and Natural Resources
Pat McCrory
Governor
December 29, 2014
Certified Mail
Return Receipt Requested
70101870 00013324 3057
Stormwater Management Division
Attn: Daryl Norris
1800 Herring Ave
Wilson, NC 27894
Subject: REQUEST FOR ADDITIONAL INFORMATION
Wingate Streambank Stabilization
Dear Mr Norris
John E Skvarla, III
Secretary
DWR #14 -1272
Wilson County
On December 9, 2014, the Division of Water Resources (Division) received your application dated
December 3, 2014 requesting a 401 Water Quality Certification and Riparian Buffer Authorization
from the Division for your project The Division has determined that your application as submitted
cannot be processed The application is on -hold until the following information is received:
The application does not include justification for the use of hard armoring (i a gabion
baskets) at this location on the stream In other words, why is it not possible to stabilize
this streambank with a less invasive technique. [15A NCAC 02H 0502(g)]
Pursuant to Title 15A NCAC 02H 0502(c) and Title 15A NCAC 02B 0233 (8), the applicant shall
furnish all of the above requested information for the proper consideration of the application If
all of the requested information is not received in writing within 30 calendar days of receipt of this
letter, the Division will be unable to approve the application and it will be returned The return of
this project will necessitate reapplication to the Division for approval, including a complete
application package and the appropriate fee
0110
No Caro
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North Carolina Division of Water RLboumL-, 1625 Ma11 SLPV 16C Ccnlcr Raleigh NC 27699 -1628 I'honc (919) 791 -4200 CLIbtormr $�.rvitc
ltltlrnl.t NNN IILNdWrtlUallt� MU t u,auvn 3800 0.— R.1" h VC 27609 Fa, (919) 788 -71 S9 1- 877 - 623 -6748
An Equal Opportunity/Affirmative Action Employer— 50% Recycled/10% Post Consumer Paper

Wingate Streambank Stabilization
DWR #14 -1272
ON -HOLD
Page 2 of 2
Please respond in writing within 30 calendar days of receipt of this letter by sending four copies of
all of the above requested information to the 401 & Buffer Permitting Unit, 1617 Mail Service
Center, Raleigh, NC 27699 -1617
Please be aware that you have no authorization under the Water Quality Certification Rules or the
Neuse Riparian Buffer Rules for this activity
Please contact Cherri Smith at 919 - 791 -4251 or cherri smith @ncdenr gov if you have any
questions or concerns
$incerel ,
anny Smith
Supervisor, ater Quality Regional Operations Section
cc DWR RRO 401 file
U S Army Corps of Engineers, Raleigh Regulatory Field Office, 3331 Heritage Trade
Drive, St 105, Wake Forest, NC 27597