20180784 Ver 1_Draft Mit Plan Comment Memo_SAW-2018-01151_20190412

DEPARTMENT OF THE ARMY
WILMINGTON DISTRICT, CORPS OF ENGINEERS
69 DARLINGTON AVENUE
WILMINGTON, NORTH CAROLINA 28403-1343
REPLY TO
ATTENTION OF:
CESAW-RG/Browning
MEMORANDUM FOR RECORD
April 12, 2019
SUBJECT: Arabia Bay Mitigation Site - NCIRT Comments during 30 -day Mitigation Plan Review
PURPOSE: The comments listed below were posted to the NCDMS Mitigation Plan Review Portal during the
30 -day comment period in accordance with Section 332.8(g) of the 2008 Mitigation Rule.
NCDMS Project Name: Arabia Bay Mitigation Site, Hoke County, NC
USACE AID#: SAW -2018-01151
NCDMS #: 100061
30 -Day Comment Deadline: March 29, 2019
Todd Bowers, EPA.-
Section
PA:Section 7.4/Table 9/Page 15: Natural Plant Community Restoration
o Schafale 2012 lists two distinct Cypress Savannas (typic and acidic). Recommend providing some
discussion and justification on which type is being implemented for the target plant community at
Arabia Bay.
• Table 9 planted total should be 10,200 based on the number of each species provided. I also noted that with
10,200 planted stems over 16 acres would result in only 638 stems per acre, well below the desired planting
density of 680.
• Section 8.1/Table 12/Page 18: Success Criteria
o If shallow freshwater marsh is expected to encompass approximately 20% of the bay area, some
discussion on this habitat type should be included in Section 7 as a subcomponent of the cypress
savannah target habitat.
• 1 am bit confused by the inclusion of many of the shrub species (namely Leucothoe racemosa, Lindera
melissafolia, and Lyonia lucida) being a) counted towards stem density and b) potentially counted toward tree
height averages. Most of the shrubs in Table 9 may not grow above 2 meters tall and contain multiple stems.
Recommend some additional clarity as to which species will be counted towards stem density and tree height
averages.
• Section 8.3/Table 13/Page 19:
o See notes above as they pertain to success criteria for vegetation. "Plant" density, which implies all
species, is dependent on stem counts, however "plant" height may only be referring to tree species.
Average plant height of 10 feet will be difficult to achieve if the shrubs are included in the height
estimations. Recommend some clarity to differentiate between planted shrubs and trees and how they
contribute to the parameter estimations for success.

Kathy Matthews, USFWS:
• The Service reviewed the public notice for this project in June 2018, before a mitigation plan was
developed. Although pondberry is not on the county list for Hoke County, it likely was historically in
the county, and is found in Carolina bays and similar habitats. Pondberry was listed as endangered on
July 31, 1986.
The Service is very pleased that Restoration Systems (RS) is proposing to plant pondberry on the site.
We do not recommend any specific requirements for monitoring or replanting of the species other than
what is already proposed. We do not recommend any specific requirements for survival of the species
on the site.
We recommend that RS ensure that the planted stems are correctly identified as the listed species, the
plants are propagated and transported in North Carolina (unless appropriate permits are in -hand for
interstate transport/commerce), and that we are provided with name and location of the propagation
facility. Also, the Service would appreciate the opportunity to survey the site in the coming years to
determine the success of the planted population. This is in addition to the annual monitoring efforts,
since we would be interested in determining population numbers over time throughout the site, and not
just in the vegetation plots. These plants are rhizomatous, frequently propagating by vegetative sprouts
and forming clonal colonies, and we hope that planted individuals will spread throughout appropriate
habitat on the site.
It is through efforts such as this that a species may be recovered and eventually down -listed or removed
from the endangered species list. We recommend that NCDMS consider recommending the planting of
pondberry in appropriate habitat (described below) to all mitigation providers, and we will strive to also
do that when given the opportunity. As you may know, plants that are not on federally -owned lands are
not subject to take provisions, (unless such take is in violation of a State law), so hopefully, other
mitigation providers will not be discouraged from planting the species.
• Habitat (USFWS website; Beckley and Gramling 2013) : Pondberry is associated with coastal wetland
habitats such as mixed pine or hardwood sinks, ponds and other depressions, including pocosins and
successional swamp forest. The plants generally grow in shaded areas but may also be found in full sun.
As for the vegetation success criteria, I believe that the loblolly recruitment may more than make up for
any deficit in numbers of planted trees. We welcome planting of additional tree species, however we
would not like to see a reduction in the number of planted pondberry stems.
The mitigation provider will need to contact the North Carolina Plant Conservation Program (NC PCP)
for a permit before planting any state -listed (which includes all federally -listed) species. Please let me
know if the Service can be of assistance in any way.
Mac Haupt, NCD WR:
1. DWR liked the discussions of the soils in the comment/response letter from DMS (Lindsay Crocker) to
RS. DWR is still concerned with the possibility of ponding (other comments will cover later). In addition,
DWR would like to know the location and soil series of the Reference Wetland that this section
(question/statement #2) referenced.
2. DMS comment letter # 10- states that much of the ditch plug material will come from "habitat areas" within
the site. DWR cautions that the depressions should not be over 6 inches in depth and obviously the IRT
does not expect to find wetland gauges in these areas. In addition, there should be some representation of
the location and extent of the depressions in the design sheets (DWR realizes the location will be
determined once construction initiates, however, there should be some plan showing extent).

3. DMS comment letter #11- as DWR reads it no surface water will leave the site unless it reaches the outlet
elevation of the Terracell structure. DWR is concerned about excessive ponding for the site. More
comments will be mentioned later regarding surveyed elevations versus QL2 Lidar.
4. DMS comment letter #12- DWR appreciates the inclusion of a water budget.
5. Section 7.3- DWR appreciates the moving of the current dirt road outside the easement, however, DWR
is concerned that the road will be built and the outlet placed based on QL2 Lidar. DWR would prefer that
these elevations would be verified by traditional survey methods.
6. Table 11- the growing season for Hoke County, as per the Soil Survey, is from April 5th to October 28th.
As been stated in the past, another growing season may be proposed based on soil temperature, however,
no growing season may start before March 1St. In addition, any change in growing season must be noted
in each wetland hydrologic summary table.
7. Table 12- DWR accepts the proposed 10% saturation minimum for this site, however, DWR will not
accept the proposed 8% saturation standard for monitoring years 1 and 2. That will be an IRT decision
once the data for these monitoring years have been reviewed.
8. Design sheets-PS4- DWR realizes the ditches will be filled to grade, however, does RS have any concerns
that the ditches, other than the plugged areas may still facilitate drainage of the wetland? In other words,
unless work is undertaken to compact the material (clay?) filling the ditches, areas may still drain. Will
RS/Axiom require the entire ditch be filled with compacted clay or non -impervious material?
9. Design sheets 5 and 6- DWR would prefer that the figures be supported with surveyed in elevations,
especially the constructed road, inlet, outlet of the Terracell and on sheet 6 spot elevations within the site
showing elevation differences near the rim and in the center of the site.
10. DWR found (in a different section than the other figures) a Figure 3 with Arabia Bay elevations based on
the QL2 Lidar. This figure should have been with the others, however, it does show a considerable amount
of elevation variation which would remove the need to create "habitat areas".
11. Figure 10 displays the monitoring components proposed for the site. DWR would like at least four gauges
placed near the outer rim or outside the innermost elevation line as seen in Figure 7. For example, DWR
would like a gauge in the outer area where the road was removed, also, the other 3 gauges should be
spaced within these outer areas. The other 11 gauges should be placed to address differences in elevation
throughout the site.
12. Each wetland gauge should be tied to a specific ground elevation. These elevations should be
representative of the site and tied to a surveyed in elevation.
Kim Browning, USA CE:
1. It is anticipated that water levels for this project will vary seasonally and across years from inundated to
dry, especially given the fact that the main input is rainfall; however, the hydrology standard should be at
least 10% (preferably 12%) across the site, with considerations to be taken in the first few years after
construction.
2. From a wildlife standpoint, I would be interested to know the amphibian species composition at the closure
of this project, both in the summer and the winter, assuming it's successful in restoring wetland habitat.
These isolated wetlands are often the only landscape feature available for amphibian reproduction in large
areas.
a. Has any consideration been made regarding the condition of the existing soil, specifically the
effects of agricultural nutrients and pesticides, on proposed vegetation and habitat? (Perhaps a
good justification for Table 7B -Habitat)
3. I would recommend conducting hydrology monitoring often, in the first few years, using a combination
of piezometers, wells and water level gauges in order to get accurate data. I think a few of the wells should
be moved closer to the outer edge of the site. Also, considering that this proposed system is rainfall driven,
perhaps gathering data on air temperature, humidity, wind speed, etc. would be beneficial in justifying the
hydrology each monitoring year.
a. Is there a reference wetland with a gauge?
4. Section 3.3: since the approved JD indicates that there are currently no jurisdictional wetlands, a 404
permit may not be required, unless the outlet of the project involves jurisdictional waters.

5. Table 6: In the reference forest ecosystem, were wetland grass species present? Since 20% of the bay area
is expected to be freshwater marsh, this may be an opportunity to incorporate desirable herbaceous species.
6. Table 11: Under Wetland Restoration, adding annual inspections of the clay plugs (if possible) may be
beneficial in ensuring you meet this parameter.
a. Also, it would be helpful to add a section in the monitoring section to including inspecting site
boundaries and terracell drop structures (I did find some of this in the Maintenance Plan).
7. It is likely that you will not be able to plant vegetation until the wetland establishes, so vegetative
monitoring may need to be extended a year.
Digitally signed by
BROWN ING.KIMBERLY• BROWNING.KIMBERLY.DANIELLE.
DAN I ELLE. 15276835101527683510
Date: 2019.04.12 10:11:16 -04'00'
Kim Browning
Mitigation Project Manager
Regulatory Division