HomeMy WebLinkAbout20061241 Ver 1_Mitigation Site Visit_20090402site visit comments
Subject: site visit comments
From: "Tammy.L.Hill" <Tammy.L.Hi11@ncmai1.net>
Date: Thu, 02 Apr 2009 14:22:23 -0400
To: Guy Pearce <guy.pearce@ncmail.net>
CC: Eric Kulz <eric. kulz@ncmail. net>
Hi, Guy!
I visited the following full-delivery mitigation projects with you and Tim on
February 24-25. My comments are included below. Most of them were also discussed
in the field, so I don't think there will be any surprises. Feel free to contact me
if you have any questions or concerns.
Potts Creek II (DWQ # 20041292) Catawba County: The main channel has a large
drainage area, moves a lot of water and sediment, and accesses the floodplain
regularly. The UTs are relatively small. The majority of the project was observed
to be stable and functioning as designed. All structures, including wooden grade
controls and one point of armoring, appeared stable. One area of bank erosion near
the top of the Rhodes Mill Creek restoration reach will be addressed with additional
live-staking during 2009. A headcut developing on UT1 will also be stabilized
during 2009. One reach along the main channel contained a couple of structures and
pools rather than the desired riffle-pool sequence; however, it was constructed per
design. The buffer trees were 6-15 feet tall and generally dense. Areas of
concern were the construction staging area in which vegetation had not grown (likely
due to soil compaction) and localized dense patches of aggressive privet and
honeysuckle. Both of these issues are slated to be addressed during 2009.
Stricker Branch (DWQ # 20061760) Cabarrus County: This project is in an urban
setting with flashy flow, lots of sediment, and a narrow floodplain along much of
its length. It's not surprising that stability has been challenging to achieve.
Erosion will need to be addressed at the top end of the project and at localized
points along the rest of the length. Supplemental vegetation planting will likely
be needed in the middle of the upper reach where woody buffer vegetation was very
sparse due to flooding. The section below Sign Drive appeared to be much more
stable with a wider floodplain and adequate tree density.
Reeds Creek Wetland Restoration (DWQ # 20061241) Iredell County: Woody vegetation
is very dense along Reeds Creek and the project edge near Hwy 21. The area from
the lake inlet into the center of the site is-much wetter and is developing into a
densely vegetated herbaceous marsh community. Based on site hydrology, this appears
to be the appropriate community structure and transition between wetland types.
While the marsh may not generate credits as a forested wetland, it appears that the
site-is well on track to provide at least the requisite 5.3 units of riverine
wetland mitigation. Polygonum sp. (tearthumb) growth is excessive in the
preservation area (no credit) between the project and the lake edge. It doesn't
appear to be invading the project area at this time, but should be watched to make
sure it doesn't threaten the success of the desired vegetation.
Zach's Fork Stream Restoration (DWQ # 20042031) Caldwell County: You and Tim made
several recommendations during the field visit that were right on: install a crest
gauge; repeat cross-section monitoring and submit correct data; address stability
issues where needed (including a point near the park road and reaches 31 and 33)
and submit photos of repairs; continue to address beaver herbivory and park staff
mowing impacts on vegetation. I would recommend early treatment of privet as it
moves into the mitigation area along the greenway trail. It is present in the
surrounding woods, so will be difficult to prevent its movement into the project,
but proactive management during the monitoring period will hopefully allow the
targeted buffer community to become more established and prevent a privet forest
from forming after release. I have a photo of the huge stonefly we saw at the site
that I need to download - if it came out OK, I'll send it to you.
Threemile Creek (DWQ # 20080238) Avery County: This was a post-construction site
visit. All reaches appeared stable and per plan, including the BMP "vernal pools"
at ditch inputs. It will be interesting to see the site develop over time;
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site visit comments
hopefully, it will prove to be attractive to trout!
Gray Farm Stream Restoration (DWQ # 20052147) Iredell County: We looked at Reach 1
in depth. The small area of erosion observed next to a log vane during the 2008
site visit appeared to have stabilized with dense vegetation growing on the bank.
The buffer was densely vegetated with herbaceous plants. Trees were growing well
over most of the riparian zone, but as you noted in the field, a few sparse areas
will need supplemental planting. Wetlands are developing in some areas of the
riparian zone, and 2 stoneflies were observed in the channel. Due to loss of
daylight, we did not look at Reach 2 as closely. It appeared to be densely
vegetated, but we did not observe the bed and bank of the restored channel. I would
like to verify that the buffer width is at least 30' in all places.
Thank you again for the whirlwind tour of these projects! Let me know if you have
any questions regarding my comments. I look forward to our next round of site
visits this Spring.
Warm regards,
Tammy
Tammy Hill
Environmental Senior Specialist
NC Division of Water Quality - Wetlands
2321 Crabtree Blvd., Suite 250
Raleigh, NC 27604
(919) 715-9052 - voice
(919) 733-6893 - fax
Tammy.L.Hill@ncmail.net
E-mail correspondence to and from this address may be subject to the North Carolina
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