20010963_Other Agency Comments_19991217

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December 17, 1999
Regulatory Division
Action ID No. 199403552, Wilmington Bypass TIP R-2633C
Mr. William D. Gilmore, P.E., Manager
Project Development and Environmental Analysis Branch
North Carolina Department of Transportation
Post Office Box 25201
Raleigh, North Carolina 27611-5201
Dear Mr. Gilmore:
Please reference the mitigation plans that have been provided to our office by your contractor,
Ecobank, Inc., for review. It is our understanding that the North Carolina Department of
Transportation (NCDOT) has selected Ecobank to provide the necessary compensatory
mitigation for the Wilmington Bypass (TIP R-2633C) including the Brunswick Outer Loop or
Brunswick Bypass (TIP R-2633AB). We strongly support your efforts to develop and complete
mitigation in advance of project impacts. However, we are concerned that planning and
implementation of these sites has proceeded with no agency involvement, including the approval
of current wetland jurisdiction. Proceeding without sufficient documentation of the amount of
non jurisdictional areas on these sites may j eopardize the amount of restoration credit that is
generated.
I have provided specific comments relative to the four plans below.
Eagle Brunswick Tract:
The site must be monitored for five years, or until all success criteria have been met,
whichever is greater.
Based on the well data that have been provided, we do not agree that the ditches have
removed wetland jurisdiction for a distance of 660 feet. For example, we note that in
1998, during a period of relatively normal rainfall, Well B and C closely mimic
"control" Wells G and H. As well B is located only 350-feet from the drainage ditch we
feel that restoration "credit" can only be given for those areas within approximately
350-feet of the ditch.
We strongly encourage the use of reference sites on which to base measures of success.
Reference sites may also allow you to demonstrate hydrologic success in those years
where rainfall is significantly below normal.
If you must base your hydrologic success criteria on the 1987 Corps of Engineers
Wetland Delineation Manual, then we would request that you use 12.5% of the growing
season as the success threshold.
- The plan does not provide rational for the separation of pocosin vs. pine flat wetland
communities. Should these areas exhibit different hydroperiods?
- As with any restoration project, baseline data upon which to compare post project
effects will be needed to support our acceptance of the various restoration and
enhancement activities on the site. We suggest that you describe and measure the
"wetland enhancement" that will occur on the site.
- We note that beyond the backfilling of drainage ditches on the property, no other
restoration measures are proposed. If. as the plan states, the target plant communities
are intact, replacement ratios will be higher than the proposed 1:1.
This site is located approximately 11 miles from TIP R-2633C and is located in the
Cape Fear River drainage basin. We consider this to be off-site mitigation.
The stream/riverine mitigation section needs much more detail. The plan suggests the
hydrologic success criteria will be identical for this and the flat wood areas. These are
different wetland community types with entirely different hydrologic regimes. The
success criteria should reflect this.
It would be beneficial if the plan described the adjacent land uses relative to the
potential for adjacent property owners to excavate ditches on the perimeter of the site.
The acreage of restoration, enhancement, and preservation as provided on page 13 in
the summary section does not agree with the acres provided in the tables on page 26.
What, if any, measures will be taken to restore or enhance existing plant communities.
Will any controlled burns be performed?
- Has site been assessed for any non-hydric soil inclusions?
Dale Tract:
Use of the MRCS Scope and Effect Guide entirely for the determination of jurisdiction
is unacceptable. During the October 21, 1999 meeting between Mr. McLendon and
Messrs. Rob Moul and Bill Hoebeck, it was noted that the south and southeast portions
of the tract appeared to contain jurisdictional wetlands. At that time Mr. McLendon
suggested that that you install monitoring wells to demonstrate the presence or absence
of the required hydrology parameter.
This site is also approximately 11 miles from TIP R-2633C and is not considered to be
on-site mitigation.
It was also noted during the October 21, 1999 meeting that the northern portion of the
tract may never have contained jurisdictional wetlands. You will need to install
monitoring wells in this area of the property to demonstrate success of the site.
On page 9 of the plan it states that "water levels will be recorded on a monthly basis".
This observation period is too long. Wells should be read a minimum of once per day.
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- If this site contains intact target plant communities, and no restoration or enhancement
measures are performed, we feel that this tract is already providing some level of
wetland habitat function. Therefor, a l: l mitigation ratio for these sites is questionable.
Rowell Branch
- As the goal of this restoration project is to restore Rowell Branch to its original location
and to restore seasonally flooded bottomland hardwood wetland community, the
hydrologic success criteria should reflect this. Use of observation wells to document "a
static water table at or within 12" of the soil surface for 5% of the growing season" will
not provide any measure of functional "lift" that will occur once Rowell Branch is
directed back into the original channel. As was noted on October 21, 1999, the relic
channel would, in all likelihood, already meet your proposed success criteria. Target
success criteria should reflect overbank flooding as well as duration of flood events that
will occur on the site once the restoration activities have been completed.
- Success criteria for trees should state that at the end of five years, 320 trees, at least five
years of age, will be present.
- What are the limits of the conservation easement relative to the restoration area? As it
appears that the site will be eventually developed, does the easement provide any
upland buffer adjacent to the restored stream? What assurances can you make that
future degradation of this site will not occur from surrounding land uses?
- We note that this site is approximately 10 miles from the known bottomland impacts on
TIP R-2633C. We continue to question whether there are suitable bottomland
restoration opportunities in the vicinity of the Wilmington Bypass project.
- Figure 2 on Page 14 shows what appears to be a road crossing on Rowell Branch on the
southern end of the project. Will this be removed as part of the restoration activities?
- Figure 6. "Notes on the Preliminary Overview of Construction" indicates that old
beaver dams will be repaired to "hold back water for establishment and containment of
fresh marsh". Does this mean that the creek itself will be dammed to create freshwater
marsh? If so, this is unacceptable.
- Table 1 And Table 3 are confusing. The plan states that loblolly pine and sweet gum
are unacceptable volunteers but that they will be planted in the restoration site.
- Page 10 indicates that a weir will be constructed on the site. Construction of a weir
across the stream channel to create freshwater marsh is unacceptable.
- Page 10. What are acceptable volunteer species?
McIntyre Tract:
- The site must monitored for a minimum of five years or until success criteria have been
met, whichever is greater.
- In general, we feel that that plan lacks sufficient detail. For example, it is unclear how
the proposed activities will result in the restoration of 25.2 acres of tidal freshwater
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marsh. As with any mitigation project, pre-project or baseline conditions upon which
to compare changes to hydroperiods, plant communities, etc is critical to our
acceptance of the project for direct impacts to tidal freshwater marsh. It appears that
the 25.2 acres of marsh that will be restored contains an existing marsh community.
It is unclear how you proposed to establish both tidal cypress-gum swamp and the
freshwater marsh communities on this site. It would be helpful to measure tidal
amplitudes and compare those to existing, target plant communities in the area. We
question whether you can establish a viable, stable cypress-gum community by leaving
the spoil islands "approximately 6" to 12" higher than the surrounding marsh
community." Deepening of the Cape Fear River channel to accommodate commercial
traffic has lead to increases in tidal amplitudes and salinity in the river in the vicinity of
the proposed project. These anthropogenic effects have lead to significant mortality to
Nyssa and Taxodium communities along the river and a shift to emergent marshes
dominated by Cladium, Typha, and Zizania.
- Based on the plan, only 0.06% of the tidal cypress/gum area will be sampled. We
suggest that you revise this such that a minimum of 2% of the site will be sampled.
- It is unclear how you propose to stockpile and permanently stabilize the significant
amount of material that will be removed from the spoil islands, road and railroad bed.
- The plan does not provide sufficient detail on proposed planting and subsequent
monitoring of the tidal marsh/shrub scrub restoration areas.
- The plan would benefit from a thorough discussion of what wetland functions will be
enhanced from the activities.
In general, we would prefer that the plans more accurately describe locations of the mitigation
sites relative to the proposed Wilmington Bypass (TIP R-2633C). All four of these sites are
approximately 11 miles from the road project and are located in a different 8-digit Hydrologic
Unit. It is our understanding that the Brunswick County portion of the bypass project (TIP R-
2633AB) is not scheduled for construction for several years. We will defer from any discussion
of the use of these sites for that project.
As these sites are not being developed as banks, NCDOT will be responsible for the success
and preservation of these sites. Additionally, NCDOT must have some property interest in these
sites including a right of entry prior to our issuance of a pen-nit for any project for which these
sites will be used. As you are aware, our acceptance of these sites for use as compensatory
mitigation for the Wilmington Bypass wetland impacts can occur only after our public interest
review.
Once the resource agencies have had an opportunity to review these plans, we strongly
encourage you to convene an on-site meeting to allow an inspection of these sites.
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Questions or comments may be addressed to Scott McLendon, Wilmington Field Office,
Regulatory Division, telephone [phone].
Sincerely, FILENAME:65DT22633.MIT
CESAW-RG-L/MCLENDON
CESAW-RG/F -1?h/s MAIL
CESAW-RG/FILE
E. David Franklin
Acting Chief, Regulatory Division
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Copies Furnished:
Mr. John Hennessy
Water Quality Section
North Carolina Department of
Environment, and Natural Resources
1621 Mail Service Center
Raleigh, North Carolina 27699-1621
Mr. Rob Moul
Land Management Group
Post Office Box 2522
Wilmington, North Carolina 28402
Mr. Alan G. Fickett
Ecobank, Inc
1555 Howell Branch Road
Suite C-200
Winter Park, Florida 32789
Mr. Tom McCartney
United States Fish & Wildlife Service
Fish and Wildlife Enhancement
Post Office Box 33726
Raleigh, North Carolina 27636-3726
Mr. Larry Hardy
National Marine Fisheries Service
Mrs. Kathy Matthews
Wetlands Section, Region IV
Water Management Division
United States Environmental Protection
Agency
Atlanta Federal Center
61 Forsyth Street, SW
Atlanta, Georgia 30303
Mr. David Cox
Highway Coordinator
North Carolina Wildlife Resources
Commission
11411-85 Service Road
Creedmoor, North Carolina 27522
Mr. Bob Stroud, Manager
Wilmington Regional Office
North Carolina Division of
Coastal Management
127 Cardinal Drive Extension
Wilmington, NC 28405
BCF:
CESAW-RG-L/MCLENDON
CESAW-RG-L/JAHNKE
CESAW-RG/FRANKLIN