20081742 Ver 1_USFWS Comments_20090209

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United States Department of the Interior
FISH AND WILDLIFE SERVICE
Raleigh Field Office
Post Office Box 33726
Raleigh, North Carolina 27636-3726
February 6, 2009
Mr. Thomas Brown
U. S. Army Corps of Engineers
Raleigh Regulatory Field Office
3331 Heritage Trade Drive, Suite 105
Wake Forest, North Carolina 27587
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2009
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Re: AID# SAW-2008-03094, Godwin Bay Mitigation Bank, Johnston County, North
Carolina
Dear Mr. Brown:
The letter provides the comments of the U. S. Fish and Wildlife Service (Service) on the
subject Public Notice (PN) issued on November 20, 2008. The PN presents a proposal to
establish the Godwin Bay Mitigation Bank in Johnston County. The applicant for a
Department of the Army (DA) permit and the bank sponsor is Restoration Systems (RS),
LLC, of Raleigh, North Carolina. These comments will address two issues. First, we
will address the wetland fill that would be necessary to construct the proposed bank.
These comments are submitted in accordance with the Fish and Wildlife Coordination
Act (FWCA) (48 Stat. 401, as amended; 16 U.S.C. 661-667d). Comments related to the
FWCA are to be used in your determination of compliance with 404(b)(1) guidelines (40
CFR 230) and in your public interest review (33 CFR 320.4) in relation to the protection
of fish and wildlife resources. Additional comments are provided regarding the District
Engineer's determination of project impacts pursuant to section 7 of the Endangered
Species Act (ESA) of 1973, as amended (16 U.S.C. 1531-1543). Second, we will
consider the merits of the proposed bank as compensation for unavoidable wetland
losses. Plans for the mitigation are provided in a prospectus, dated September 2008, that
accompanied the PN.
Existing Project Area
The project site is a Carolina bay approximately four miles southeast of the Town of
Benson. Carolina bays are isolated, ovate, depressional wetlands, located exclusively in
the southeastern coastal plain, that have a unique and characteristic geomorphic structure
(shape, alignment, and surrounding rim) and a hydrology dominated by precipitation
inputs and evapotranspiration losses (Sharitz and Gresham 1998, p. 344). The mitigation
plan refers (Section 1.0) to Carolina bays as "small basins unto themselves."
2
Godwin Bay has a surface area of 575 acres and was cleared, grubbed, and drained for
agricultural production in the 1980s. The prospectus states (Section 1.0) that the farm
occupies more than 190 acres of the interior landscape of the bay. Elsewhere the
prospectus states (Section 3.1) that 160 acres are farmed. Agricultural areas are regularly
fertilized and subjected to pesticide applications which collectively represent toxic and
eutropic input to streams. The bay has an extensive system of artificial ditches. Breaks
in the bay rim allow water to leave the site and flow southeast to Mill Creek and Stone
Creek. Drainage outfall from the ditch system moves water southeast to a collector canal
located outside the rim of the bay. This water enters the Neuse River northeast of
Bentonville.
Proposed Actions
The sponsor seeks to establish a mitigation bank by restoring and preserving non-
riparian, palustrine wetlands within Godwin Bay. The actual bank would consist of
approximately 77 acres. If the entire surface area of the bay is 575 acres, the portion to
be restored would represent only 13.4% of the historic bay. From information provided
in the prospectus it is unclear whether any other parts of the historic bay are not being
drained and retain natural plant cover. This information should be provided since, to
some extent, the habitat values and hydrologic functions of Carolina bays are derived
from intact systems. The division of Carolina bays between undisturbed areas and areas
of intensive agriculture may not provide wetland functions and values in direct proportion
to the area of these different sections.
The plan calls for filling and plugging 14,000 linear feet of existing drainage ditches.
However, drainage ditches between the area to be restored and agricultural areas would
remain open. Approximately 9.67 acres within the 77-acre area and adjacent to the open
ditches would not have jurisdictional wetland hydrology restored. An additional 1.5
acres within the site do not have hydric soil and would be excluded from the bank.
Therefore, the sponsor is proposing to restore approximately 65.9 acres of non-riparian
wetlands.
A reference wetland system has been designated approximately seven miles south of the
site. The woody plants in the canopy and subcanopy of the reference site are given in
Table 4.
The plan provides (Section 6.) a restoration plan. Shallow depressions would be
constructed at random spacing throughout the surface area of the site. Certain "non-
critical ditch sections" may remain partially open to enhance habitat diversity and
hydrologic storage. Hydrologic success over the five-year monitoring period would
include the minimum jurisdictional requirement of saturation within one foot of the soil
surface for 12.5% of the growing season. The strip of land (9.67 acres) adjacent to the
open ditches along the southern and western borders of the bank would "need to be set to
5% of the growing season."
Plans for vegetation planting and nuisance species management are provided (Sections
6.6.1 and 6.6.2). Based on the reference site, the primary plant communities appropriate
for the bank include non-riverine swamp forest, pond pine woodlands, bay forest, or
intergrades among these communities (Section 6.6). While any mitigation bank will
eventually need to designate wetland types according to the North Carolina Wetland
Assessment Method (NCWAM), the Service believes that the community types provided
by Schafale and Weakley (1990) can be useful for planning purposes and plant species
selection.
Federally Protected Species
The Service has reviewed the discussion of federally protected species in the plan
(Section 3.6.1). We agree that the spring flowering goldenrod (Solidago verna) is the
only rare species in the North Carolina Natural Heritage database within two miles of the
bank site. This plant can be found in a wide array of habitats, including pine savannas,
pocosins, and pine barrens. While this species has a state designation of threatened, it is
a Federal Species of Concern (FSC). A FSC is under consideration for listing, but
current information is insufficient to support listing at this time. A FSC may or may not
be listed in the future. Every effort should be made to avoid adverse impacts to any FSC
in order to prevent the need for formal listing in the future.
Among the federally listed species reported in Johnston County, the plan is correct in
stating (p. 7) that the federally endangered Michaux's sumac (Rhus michauxii) is the only
species that requires consideration in the project area. The occurrence of this plant in
Johnston County is a historic record which means the species was last observed more
than 50 years ago. The plan states that walking surveys were made in July and August
2008 for this plant on land adjacent to the drainage ditches. No plants were seen.
In accordance with the Endangered Species Act of 1973, as amended, (ESA) and based
on the information provided, and other available information, it appears the action is not
likely to adversely affect federally listed species or their critical habitat as defined by the
ESA. We believe that the requirements of section 7 (a)(2) of the ESA have been satisfied
for this project. Please remember that obligations under the ESA must be reconsidered if.
(1) new information identifies impacts of this action that may affect listed species or
critical habitat in a manner not previously considered; (2) this action is modified in a
manner that was not considered in this review; or, (3) a new species is listed or critical
habitat determined that may be affected by the identified action.
Service Concerns and Recommendations
The subject PN has two aspects. First, there is the wetland fill associated with the
creation of the proposed bank; and second, there are the merits of the bank itself. With
regard to wetland fill, the Service has no objection to such fill. The elimination of the
artificial ditch network on the site would have minimal adverse impacts to fish and
wildlife resources.
4
With regard to the proposed bank and the mitigation plan, the Service does have
concerns. Carolina bays are unique landscape features on the coastal plain and as
"isolated depressions" (Shantz and Gresham 1998, p. 344), it seems reasonable to
consider each depression as single, indivisible habitat area. As noted, the mitigation plan
refers to Carolina bays as "small basins unto themselves." The proposed mitigation effort
would only restore a portion of the bay. If the bay surface acre is 575 acres (Section 1.0),
the 77 acres within the bank represents only 13.4% of the drainage area of the bay. It is
unclear whether this restoration would be an addition to other natural areas within the bay
or represent the only natural area within the bay. Furthermore, a considerable portion of
the boundary of the bank would be separated from ongoing agricultural operations by a
single drainage ditch. The sharp, artificial boundary between restored wetlands and
drained, agricultural areas is a source of concern.
The Service is concerned that the restoration area may not develop a truly natural
Carolina bay hydrology due to the drainage of the larger unrestored area which would
continue to share the interior of the bay. Carolina bays characteristically have no natural
drainages or artesian sources, thus their water inputs are primarily direct precipitation and
runoff from surrounding areas (Shantz and Gresham 1998, p. 346). Natural Carolina
bays may have a wide range of hydrologic conditions, including permanent to semi-
permanent open water ponds (Sharitz and Gresham 1998, pp. 354-355): If the boundary
drainage ditch is intended to drain sandy, subsurface soil horizons on the agricultural
side, then there are concerns that the same soil layers would be drained within the
proposed bank.
The drainage ditches along the southern and western edges of the bank could continue to
remove more water than that predicted by the DRAINMOD hydrologic model. The
mitigation plan notes (p. 15) that success criteria outlined by the groundwater model
indicate that the wetland restoration area should maintain saturation within one foot of
the soil surface for a least 74% of the hydroperiod exhibited by reference wetland gauges
in any year. This degree of variation, approximately a fourth, creates concerns about the
restoration of a natural hydrology. The hydrologic success criterion for the bank should
be based on an intact Carolina bay, such as the proposed reference site, rather than the
minimal regulatory requirement of 12.5% of the growing season. The current plan
(Figure 7) shows only one strip of monitoring wells along the western and southern
boundary lines of the bank. The Corps and the review team should consider whether
additional monitoring well transects along these boundaries are necessary to better
determine the hydrology within the bank and the extent of any artificial drainage from the
restoration area.
At this time, the restoration plant list (Table 3) appears acceptable. The plans for
vegetation monitoring (Section 7.3) appear adequate. However, the plan should be
revised to incorporate a seven year monitoring program for forested wetlands and a seven
year credit release schedule.
The vegetative success criteria given in the plan (Section 7.4) is cursory and only
addresses the absolute abundance of "character trees," presumably those species given in
Table 3, over five years. Absolute abundance refers to the number of tree stems per acres
within the restoration area. As noted, vegetative criteria for forested wetland restoration
extend over a seven-year monitoring period. These criteria are given in the letter of the
U. S. Environmental Protection Agency (USEPA), dated December 8, 2008. In addition
to absolute abundance, vegetative success should also consider both relative abundance
(the number of character tress in relation of undesirable invaders, a measure of
competition in forming the eventual canopy of the mature wetland) and species diversity.
Both of these criteria are addressed by the USEPA. While the Service has recommended
different language for relative abundance and species diversity in the past, the criteria
given by the USEPA are acceptable until modifications can be approved by the
Interagency Review Team. The Service does recommend one point with regard to
species diversity criterion. As stated by the USEPA, if, within three years, any species
exhibits greater than 50 percent mortality, the species will either be replanted or an
acceptable species will be planted in its place. The Service recommends that a new
monitoring period should be started at the time any new vegetation is planted. There
should be a provision in the Mitigation Banking Instrument that a specified number of
credits will be withheld until the replacement plants are found to be successfully
established. Furthermore, there should be language to require additional planting if there
is significant mortality following any remedial planting. Replanting after significant
mortality of wetland vegetation should not be limited to a one-time action. Overall,
vegetative success should require the survival of at least 210 stems per acre of
"character" species (absolute abundance) for at least seven years on the restoration site
with a low level of competition from undesirable volunteer species (relative abundance)
and an adequate number of the species for the mature canopy (species diversity) on the
restored site.
The executive summary of the plan states that the bank, when fully functional, would
provide "enhanced foraging, nesting, and refuge opportunities for mammals, birds,
amphibians, and reptiles." This goal is consistent with the position that the primary
habitat value of Carolina bays may be as refuges for fragmentation-sensitive species
(Shantz and Gresham 1998, p. 368). In area with intensive farming, many species of
amphibians, reptiles, and small mammals have clumped distribution patterns with the
areas of highest density being associated with Carolina bays (Shantz and Gresham 1998,
p. 368). While birds and highly mobile species would undoubtedly benefit from the
restoration effort, the Service is concerned that smaller, less mobile species that are
commonly found in Carolina bay wetlands may have difficulty colonizing the restored
area. If Godwin Bay is an "isolated elliptical depression" (Shantz and Gresham 1998, p.
346) and is now drained and surrounded by uplands, it is questionable whether the
smaller, less mobile fauna of atypical Carolina bay would be able to colonize the small,
restored area of this bay. Furthermore, the birds and more mobile terrestrial animals that
use the restored area may not find an animal prey base of a typical Carolina bay.
Overall, the proposed bank would provide some wildlife value such as nesting habitat for
birds and a refuge for some mobile, terrestrial wildlife species. The most significant
issue regarding the ability of the proposed bank to compensate for wetland losses
elsewhere in the geographic service area will involve the water quality benefits produced
6
by the restoration in only a portion of this Carolina bay, a landscape feature which the
sponsor refers to as "small basins unto themselves."
With due considerations of the recommendations contained in this letter and those
provided by the USEPA letter of December 8, 2008, the Service does not oppose this
mitigation banking effort from a perspective of fish and wildlife resources. We hope that
this initial effort may provide a foundation for future work to restore the entire bay.
We appreciate the opportunity to comment on this permit application and mitigation bank
proposal. If you have questions regarding these comments, please contact Howard Hall
at 919-856-4520, ext. 27 or by e-mail at < [e-mail] >.
Sincerely,
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Peter Benjamin
Field Supervisor
cc:
Kathy Matthews, USEPA, Durham, NC
Molly Ellwood, NCWRC, Wilmington, NC
Eric Kulz, NC DWQ, Raleigh, NC
Literature cited
Schafale, M.P. and A.S. Weakley. 1990. Classification of the Natural Communities of
North Carolina Third Approximation. NC Natural Heritage Program, Raleigh,
NC 325pp.
Sharitz, R. R. and C. A. Gresham. 1998. Pocosins and Carolina Bays. pp. 343-377. in
M. G. Messina and W. H. Conner (eds) Southern Forested Wetlands - Ecology
and Management. Lewis Publishers. Boca Raton, FL. 616 pp.