20061760 Ver 2_Mitigation Site Visit_20071019

IV
NC Division of Water Quality
401 Oversight and Express Permitting Unit
October 19, 2007
Memorandum
To: Scott McLendon - USACE
File
From: Eric Kulz
Subject: Comments on NCEEP Full-Delivery Site Visits - September 25 - 27
Scott:
The following are DWQ's comments on the seven NCEEP Full-Delivery Sites visited
McDonalds Pond - Richmond Countv (Monitoring Year 2)
This site was evaluated without the benefit of having copies of the mitigation plan (DWQ files off-
site being scanned), as-built-plan or monitoring reports (not provided to DWQ) available.
However, the notable feature at this site was substantial amounts of water, despite the drought
conditions. No hydrology data were reviewed.
The wetland restoration and enhancement areas appeared to have sufficient hydrology, as most
areas were inundated. Herbaceous growth appeared lush, and trees appeared to be present in
adequate diversity. Stem density was difficult to observe in some areas because of dense
herbaceous growth, but overall, vegetation appeared good for a 2nd-year project.
The restored stream channel constructed within the footprint of the pond appeared to be stable,
despite the lack of structures. Flow was quite strong, and woody debris was observed at a
number of locations, resulting in increased turbulence in flow and habitat diversity. Riparian
vegetation was noted above, as wetlands are adjacent to the stream channel.
The stream and wetland restoration/enhancement portions of the site appeared to be successful
at this point. It should be noted that based on limited observations of the stream preservation
reach above the former pond site, the quality of this stream feature appeared high. We look
forward to the continued success of this project.
Jones Creek - Anson County (Monitoring Year 2)(? 2005?1o'JS
This site was evaluated without the benefit of having copies of the mitigation plan (DWQ files off-
site being scanned), as-built-plan or monitoring reports (not provided to DWQ) available. A
summary of hydrology data from the wetland was provided on-site.
According to the hydrology data reported on-site, five of 14 gauges showed inundation or
saturation for greater than 7% of the growing season (presumably consecutive days), and 4 of the
gauges showed saturation or inundation between 5% and 7%. The remainder of the gauges (5)
apparently did not meet in the success criteria for hydrology. Hydrology will need to be watched
North Carolina Division of Water Quality; Wetlands/401 Unit
1650 Mail Service Center; Raleigh, NC 27699-1650
2321 Crabtree Blvd., Raleigh, NC 27604-2260
Telephone: [phone]; Fax: [phone]
http://ncwaterquality.org/wetlands
closely at this site. Woody vegetation density in the wetland areas appeared variable, although
as noted in the previous site comments, herbaceous vegetation may be obscuring the view of
some of the planted trees. According to the project summary, stem density averaged 625 stems
per acre. However, I did note that sycamore made up the vast majority of trees I saw, with some
scattered green ash in spots. Vegetation monitoring data, including species diversity, should be
closely monitored in the future.
The stream (UT to Jones Creek) appeared stable, and no issues with installed structures were
observed. However, it is not known if any bankfull events have occurred, and what effect these
may have on the constructed channel. Flow in the stream appeared adequate, although cattails
were observed growing across the entire stream bed in a riffle. This may be a result of low flow
associated with drought conditions. As described above, trees were observed in the riparian
buffers, but appeared sparse and consisted mostly of sycamore, with several other species (black
gum, swamp chestnut oak) observed in small numbers.
The riparian zones appeared quite dry, likely due to the drought, and this may have an effect on
tree survival.
The most significant issue at this site is the hydrology data in the wetland. DWQ hopes to see
improved tree diversity in both the wetland and riparian buffer areas as the trees get larger.
Stricker Branch - Cabarrus County (Under Construction) 'DCOQ *2pD(.01-ILOC)
DWQ reviewed the application and mitigation plan for this site on 1/23/07.
Earthwork had been completed on the lower reach and structures were installed. Some live
stakes were observed. Riparian zone planting had not yet been completed.
The middle reach has had some earthwork done, but benches appeared small and slopes were
steep.
The upper reach consisted of the bed of a pond in which a stream channel was present which
appeared to have formed naturally.
DWQ has significant concerns about this project, mainly due to contractor issues. The stability of
the middle reach in its current state, even with vegetation, is suspect. With regard to the lower
reach, a constriction at the sewer line crossing represents a stability issue, as high flows through
this constriction will likely cause degradation immediately downstream.
Plans for the upper reach/former pond were discussed at the site. The possibility to incorporate
wetlands and even possibly install a low weir to provide some detention in the wetlands to effect
stormwater treatment was discussed.
Since the site is under construction and not complete, no statements regarding success can be
made. As discussed above, contractor issues are a concern. Delay of completion of the project
could result in problems if significant rain events occur while the project is in an incomplete state.
Beaverdam Creek - Mecklenburg County (Monitoring Year 1)
This site was evaluated without the benefit of having copies of the mitigation plan (DWQ files off-
site being scanned) or as-built-plan (not provided to DWQ) available.
The site visit was limited to walking most of UT1 due to time constraints. Stream stability at the
downstream end of the tributary appeared satisfactory. However, some undercut banks and
erosion around structures (e.g. rootwads) were observed as we progressed upstream. The
North Carolina Division of Water Quality; Wetlands/401 Unit
1650 Mail Service Center; Raleigh, NC 27699-1650
2321 Crabtree Blvd., Raleigh, NC 27604-2260
Telephone: [phone]; Fax: [phone]
http://ncwaterquality.org/wetlands
potential start of a headcut was observed in area within the power line easement. Further
upstream from the power line easement, more indications of unstable banks were observed.
Little water was observed in the channel. The system appears to be somewhat flashy due to
stormwater inputs from 1-485, and DWQ is concerned that a return to normal rainfall patterns will
challenge the stability of the constructed stream channel.
Woody vegetation density appeared variable, although as noted in the previous site comments,
herbaceous vegetation may be obscuring the view of some of the planted trees. However, I did
note that sycamore made up the vast majority of trees I'saw, with some river birch in spots.
There was not much evidence of the presence of live stakes in the streambank areas. This may
contribute to stability problems in the future.
Since the site was completed in spring 2007 and no monitoring data has been collected, no
statements regarding success can be made. Stability issues remain our chief concern.
South Fork - Catawba County (Monitoring Year 31 -'jq 4 20a4 11+8Z
This site was evaluated without the benefit of having copies of the mitigation plan (DWQ files off-
site being scanned), as-built-plan or monitoring reports (not provided to DWQ) available.
The site visit was limited to walking the South Fork North project site only due to time constraints.
The stream channel segments obse.ryeq appeared stable, and no issues were noted with the
structures observed, aside from one vai which was piping slightly. Flows in the sections looked
at appeared low, especially in pools, bWAowing water was observed at all locations visited.
Herbaceous vegetation was extremely dense, and tree stem density was variable but appeared
satisfactory. Diversity appeared fairly good, with sycamore again being prevalent, but with good
quantities of green ash and river birch. Volunteer species were observed at numerous locations,
including black cherry, red maple, and persimmon.
Overall, the success of this project appeared encouraging, and we look forward to reviewing the
3rd year monitoring report for the site.
South'Muddy Creek Tributaries - McDowell County (Monitoring Year 1) DWQ *`2-C%o50col?
This site was evaluated without the benefit of having copies of the mitigation plan (DWQ files off-
site being scanned), as-built-plan or monitoring report (not provided to DWQ) available.
The summary for the project reported bank stability issues at a number of locations. Some areas
of erosion were noted, but the banks overall appeared to be stable.
The project is rather odd in that few structures were used, but instead the stream exhibits
significant sinuosity. The pattern did not exhibit well-defined riffles and pools, and the bed
consisted almost entirely of sand. One structure that was observed on the middle portion of the
project was actually impounding water slightly, and plants were growing across the channel at
this location. A fairly significant area of bank erosion (blowout) was observed immediately
downstream of this structure.
The main issues at this site involve the buffers/riparian areas. According to the NC Ecoregions
Map, the site is located near the boundary between the Inner and Outer Piedmont; therefore,
buffer should be 50 feet unless otherwise approved by the agencies. Buffer widths varied across
the site, with areas less than 10 feet wide in the upper section where the landowner had mowed.
The access road along the east side of the stream, between the stream and the farm field,
appeared to be in the easement, and portions of the eastern buffer were of inadequate width.
North Carolina Division of Water Quality; Wetlands/401 Unit
1650 Mail Service Center; Raleigh, NC 27699-1650
2321 Crabtree Blvd., Raleigh, NC 27604-2260
Telephone: [phone]; Fax: [phone]
http://ncwaterquality.org/wetiands
Tree density was extremely variable throughout the project, with some areas with few or no trees
whatsoever. The summary report provided stated that 18 of 30 vegetation plots did not meet
success criteria for stem density. Trees consisted mainly of green ash, swamp chestnut oak,
and sycamore. Herbaceous vegetation was fairly dense, but consisted mainly of fescue, and in
one section of the project, lespedeza.
Overall, this project appeared to have many issues, but most of the issues were mainly involved
the landowner, and are therefore resolvable. Vegetation success needs to be monitored. We
look forward to reviewing future monitoring reports for the site.
Little White Oak Creek - Polk County (Under Construction) DLX * 20 _7 DU2Z
DWQ reviewed the application and mitigation plan for this site on 5/3/07
Earthwork had been completed and structures were installed on the portions of the project on the
north side of NC Highway 9. Some live stakes were observed. Seed mix (temporary) had been
spread and watering was taking place. Riparian zone planting had not yet been completed aside
from transplants. Earthwork was in progress 'on the portion of the project on the south side of US
Highway 9.
Some erosion around structures was observed on the portion of the site on the north side of NC
Highway 19. In addition, the placement of some of the structures within the pattern of the stream
channel was questionable. The consultant on-site stated that the completed portion of the stream
project would be re-evaluated and the structures modified as necessary as part of the on-going
project work.
Since the project is currently under construction, no statements regarding success can be made.
We look forward to receiving copies of the as-built drawings and 15? monitoring report.
North Carolina Division of Water Quality; Wetlands/401 Unit
1650 Mail Service Center; Raleigh, NC 27699-1650
2321 Crabtree Blvd., Raleigh, NC 27604-2260
Telephone: [phone]; Fax: [phone]
http://ncwaterquality.org/wetlands