20070972 Ver 1_Staff Comments_20070612

1
NC Division of Water Quality
Wetlands/401 Unit
June 12, 2007
Memorandum
To: Cyndi Karoly
Ian McMillan
Kyle Barnes
File
From: Eric Kulz
Subject: Comments on PCN and Stream & Buffer Restoration Plan/BMP Installation -Adkin
Branch -Lenoir County. KO & Associates plan for EEP; EEP Design-Build Project??
(DWQ# 20070972)
Tammy and I both looked at this PCN/restoration plan. They are proposing to restore approx.
10,100 LF of urban stream (Adkin Branch and a UT to Adkin Branch) in Kinston. They are
proposing Priority II restoration for Adkin Branch and a combination of I & II for the UT. They are
planting Neuse Riparian Buffers (currently grass mostly), but will not have 50 feet along all
sections due to existing constraints.
They are also proposing a constructed wetland along both sides of the upper end of the UT for
stormwater treatment. Not in-stream treatment, per se, but they will be capturing some of the out-
of-bank flow as well as stormwater in these adjacent wetlands.
They are also proposing a bunch of sand filters for stormwater outfalls. They say they can't do
wetlands because the depth to GW is too deep.
The project generally looks pretty good, as there is not a lot of great options for urban stream
restoration. The main things are the addition of planted riparian zones, stabilization of eroding
banks, construction of floodplain benches, and addition of some in-stream structure (wood only),
which should improve the system
1 would like Annette to look at the sand filter design calculations; I have never looked at
these before, and they don't mean much to me. Also the odd stormwater wetland.
We have additional concerns about their vegetation monitoring criteria. They are planting
appropriate species, but include in their "character species list", which was compiled based on
other forested areas near the site, loblolly pine and sweetgum. The success criteria does not
contain any provisions for ensuring that no tree species comprise more than 20% of the total
trees counted for evaluating success. Based on how the plan is written, at the end of the
monitoring period, there theoretically could have all sweetgum and loblolly pine, and as long as it
meets or exceeds the stems per acre criteria, it would be deemed successful.
In addition, the plan never states whether Neuse riparian buffer mitigation credit is being sought
for the project.
North Carolina Division of Water Ouality; Wetlands/401 Unit
1650 Mail Service Center; Raleigh, NC 27699-1650
2321 Crabtree Blvd., Raleigh, NC 27604-2260
Telephone: [phone]; Fax: [phone]
http://ncwate rqual ity. org/wetl ands