20180179 Ver 1_MP_FINAL_IRT Response Letter_20190916

September 16, 2019
US Army Corps of Engineers
Regulatory Division, Wilmington District, Asheville Field Office
Attn: Steve Kichefski
151 Patton Ave, Suite 208
Asheville, NC 28801

RE: WLS Responses to NCIRT Review Comments Regarding the WLS Yadkin 01 Umbrella
Mitigation Bank (UMBI) Final Mitigation Plan Approval for the Grassy Creek Tributaries
Mitigation Project, USACE AID# SAW-2017-02528, Upper Yadkin River Basin, Cataloging Unit
03040101, Surry County, NC Dear Mr. Kichefski: Water & Land Solutions, LLC (WLS) is pleased to provide our written responses to the North Carolina Interagency Review Team (NCIRT) review comments dated August 30th, 2019 regarding the Draft Mitigation Plan for the Grassy Creek Tributaries Mitigation Project. We are providing our written responses to the NCIRT’s review comments below, which includes editing and updating the Final Mitigation Plan and associated deliverables accordingly. Each of the NCIRT review comments is copied below in bold text, followed by the appropriate response from WLS in regular text:
Mac Haupt, NCDWR Comments:
1. Section 3.6.2-Existing Reach Descriptions-during the site visit DWR thought there were some
wetlands adjacent to R3 and in addition, the possibility of some restoration or enhancement due
to the raising the channel bed. There was no mention of any wetlands in the reach description for
R3 (the wetlands were mentioned in Section 3.7), however, some are present in the PJD and in the
initial proposal some wetland re-establishment was proposed. Response: As described in the Prospectus, WLS proposed wetland restoration/re-establishment (W1) along R3 and wetland enhancement (W2) along R4 based on preliminary site evaluations. After the IRT site visit (1/8/18), WLS conducted a wetland delineation and a more detailed soils evaluation. We determined the overburden soil along R3, near wetland area ‘WA’, was from the adjacent/historic channel excavation and approximately 18”-24” deep consisting of red clay atop a buried hydric soils layer. The steam restoration approach for R3 will involve channel relocation, removing the overburden, and placing the material back into the old channel. Given that the depth to hydric soils is greater than 12” below the surface, WLS was concerned this would be considered ‘creation’ rather than ‘re-establishment’ as suggested by IRT guidance. Additionally, since we are not modifying the channel geometry or stream bed elevation along R4, the existing jurisdictional wetland area ‘WB’ will not likely be impacted. Current jurisdictional wetlands are shown in Figure 7. Wetland area ‘WA’ is located on the left floodplain of the proposed alignment of R3, and wetland area ‘WC’ is also located on the left floodplain of R3 where this reach transitions to Enhancement Level II. Wetland area ‘WC’ will not likely be impacted and is located almost entirely outside the proposed conservation easement. Wetland area ‘WC’ has been added to the R3 description in Section 3.6.2. There are no wetlands described in the existing conditions section for R3 because ‘WA’ is not adjacent to the existing R3 location. WLS is not proposing any wetland credit on this site.
2. Section 3.6.2-Reach 5-this section discusses a gravel laver approximately 3 feet down as
evidence of its incision. However, in the design sheet for this reach (17) it appears that the channel
bed is only being raised a foot or so on average. This brings into question the functional uplift for
this reach and the ratio proposed. Response: The gravel layer was observed mainly downstream of station 12+20 along R5 below an active headcut and continues through R7 to its confluence with R2/R3. The upper section of R5 (approx. station 10+00 to 12+20) will be a transitional zone to allow the proposed channel to tie into the existing channel upstream and gradually raise the stream bed in the downstream direction to provide as much functional uplift as possible, while incorporating the proposed design parameters including bedform diversity such as riffle/facet slopes and pool to pool spacing. In the mid to lower section of reaches R5, and most of R7, there are many areas where stream bed fill is at or above the observed gravel layer. WLS measured channel fill in several areas along R5 and R7 at structure locations (log steps, riffles, rock steps, etc.). The channel fill ranges from 1.2’ to 4.0’ with an average of 2.0’ (this excludes the upper transitional zone of Reach R5 station 10+00 to 12+20). The design profile along these reaches will raise the stream bed elevation to provide as much functional uplift as possible, while making sure that stream jurisdiction is maintained and adequate floodprone width areas are achieved. The design of these reaches and all other reaches included balancing cut/fill to reduce offsite haul of soil. WLS believes the restoration approach in these reaches provides the highest functional uplift possible while balancing cut/fill material, offsite haul, and ultimately reducing the sites carbon footprint.
3. Section 6.2.3-Planting Materials and Methods-this section states that the trees must be installed
by the end of May to meet the requirements for the first year of monitoring. If tree species are
planted past March, DWR and the IRT will review closely the survivability of those species and if
survivability is reduced or low, it is likely the IRT will require an additional year of vegetative
monitoring. DWR recommends planting by the end of March. Response: WLS understands that the IRT prefers that trees be planted between November to March. The IRT guidance also requires that vegetation and plots must be established 180 days prior to initiation of the first year of monitoring, which could allow planting in May. The growing season in Surry County begins around April 24th and WLS will do their best to plant trees by April. If WLS plants in May we understand that the IRT will review closely the survivability of the trees and reduced survivability could result in an additional year of vegetative monitoring.
4. Section 8–Performance Standards-please specify the flow standard for intermittent (only)
streams is 30 days of continuous flow. Response: We have revised Section 8 to include this language.
5. Design sheet 3-DWR would prefer to see the typical cross sections with side slopes with a
specific slope labeled, such as 3:1 for riffles or 2:1 for side of a pool. Response: The average side slopes/ranges have been added on design sheet 3 and are within a common stable range of Rosgen C4 and B4 stream types. The typical section illustrations have been modified to represent more proportional dimensions.
6. Design sheet 14 or 15-please include the jurisdictional wetlands on the design sheets so we can
see if any channel will be constructed through wetlands. Response: The jurisdictional wetlands have been included on the design sheets (14, 15 and 16).
7. Design sheets 17 and 18-as stated above-and from recalling discussions on site and verbiage in
Section 6.2.1, DWR was under the impression that the severely incised reaches, R5, R6, R6a and R7
would have the channel beds raised significantly. However, except for a portion of R6a and R6 most
of the reaches are raised only a foot or so. Given this fact, DWR is calling into question the
restoration ratio being utilized for these reaches. Response: Please see the comment response to question 2 regarding reaches R5 and R7. Reaches R6 and R6A where designed similar to R5 and R7 in that there is a transition zone in the upper section and below the active headcut where the channel fill is much more pronounced. WLS measured channel fill in several areas along R6 and R6A at proposed in-stream structure locations (i.e., log and rock steps, riffles, etc.). The channel fill in R6 ranged from 1.8’ to 3.8’ with an average channel fill of 2.8’ (this excludes the upper transitional zone of Reach R6 station 10+00 to 10+75). The channel fill in R6A ranged from 2.1’ to 3.0’’ with an average channel fill of 2.5’ (this excludes
the upper transitional zone of Reach R6A station 10+00 to 10+29). The design profile along these reaches will raise the stream bed elevation to provide as much functional uplift as possible, while making sure that stream jurisdiction is maintained and adequate floodprone width areas are achieved. The design of these reaches and all other reaches included balancing cut/fill to reduce offsite haul of soil. WLS believes the restoration approach in these reaches provides the highest functional uplift possible while balancing cut/fill material, offsite haul, and ultimately reducing the sites carbon footprint.
8. DWR requires the installation of a stream gauge for R6 at station 11+30. Response: WLS has added a proposed stream surface flow gage to R6 at approximate station 11+30 on Figure 11 (Proposed Monitoring Features).
9. Why did WLS not run the Stream Quantification Tool for R4? Response: R4 was originally proposed as a Preservation reach in the Prospectus and we had not included an SQT score/form. After conducting subsequent fields assessments, WLS determined the reach condition has worsened and is experiencing localized bank erosion and excess aggradation thus worthy of Enhancement Level II activities. We have included an SQT score/form for R4 in Section 4.1.2, Table 9, pg 27 (App B) the to show the expected functional lift and justify the proposed enhancement activities.
10. As documented in the meeting minutes from the January 9, 2018 site visit, DWR recommended
a ratio of 8:1 for R4. The current ratio for this reach is listed as 5:1. While there are four planned
meander bend activities, the cattle usage of this reach was limited if at all. DWR recommends the
proper ratio for this reach to be closer to 7.5:1 than 5:1. Response: In recent conversations with the landowner, cattle do have access to this reach. The landowner flash grazes this area of the property across R4 for 5 days a few times a year. However, due to fence in disrepair, cattle have not grazed this land for the past 2 years. WLS measured the lengths of proposed stream improvements along R4 at approximately 156 LF. This includes the bank stabilization treatments, reshaping the thawleg in aggradation areas, in-stream structures, and protecting vegetation buffers greater than 100 feet wide (with supplemental planting as needed). The remaining 966 LF, as well as the 156’ of enhancement level I work, will be supplementary planted along the stream banks and across the floodplain where the previous cattle access have negatively impacted the understory vegetation. Any areas disturbed during construction will be replanted and protected with a conservation easement in perpetuity. Based on this approach, WLS originally proposed an average stream enhancement ratio of 5:1 for the entire reach length, the 966 LF at a ratio of 8:1 and 156’ at 1.5:1 respectively. This would provide a total of 225 stream mitigation credits (SMCs) in this reach.
11. What is the status of the proposed project for stream restoration work in the State Park
between Reach 1 and Reach 2? If this project is not done, DWR would like to know the approach
WLS will take to keep both adjacent reaches from destabilizing. Response: WLS submitted grant applications to both the NC Clean Water Management Trust Fund (CWMTF) and NC DWR in Spring 2019 for the proposed stream restoration activities within the Pilot Mountain State Park (Park) property. At the time of this comment response letter, both applications have been reviewed and scored favorably as compared to similar projects submitted in that round. Per CWMTF and DWR, we anticipate project review decisions by mid-October and will notify the USACE/IRT of the grant approval status and any potential design changes immediately upon notification. As described in the final mitigation plan and shown on the design plan sheets, the proposed design profile and hydrologic & hydraulic modeling for reaches R1 and R2 currently tie into the existing channel elevations at stable slopes and adequate floodplain widths. Restoring the channels above and below the Park corridor will reduce in channel shear stress and erosion potential while allowing fine sediment to deposit naturally onto the reconnected floodplain. The project/construction timing for the mitigation site is anticipated to begin early winter and site planting completion by spring 2020. Any design changes as a result of the Park project approval will be incorporated into the transition/tie in locations to ensure channel stability and overall project success.
Andrea Leslie, NCWRC Comments:
1. Neither the Toms Creek or Grassy Creek project should negatively impact wild trout during
construction, and a trout moratorium is not needed. Response: Noted.
Steve Kichefski, USACE Comments:
1. Section 3.7. Add wetland labels to appropriate figures and plans, such as Figure 7 & 10. Response: The existing jurisdictional wetlands have been added to the design sheets (14, 15 and 16) per DWR Comment #6. Figure 7 has the existing jurisdictional wetlands labeled and WLS prefers to not add the wetlands to Figure 10 (Proposed Mitigation Features) as we are not proposing any wetland mitigation credit. We do not anticipate wetland impacts as a result of the restoration activities and any expected changes will be included with the PCN permit application.
2. Section 3.8.5 (p24): Recommend treating the “small, immature Chinese privet plants” to help
prevent future proliferation within the area if property owners amenable to it. Response: WLS will treat the immature Chinese privet plants within the Project boundaries and along the immediate periphery to help prevent future proliferation during the monitoring period.
3. Section 3.9.2: Has there been any coordination with the USFWS to date regarding potential
presence for Schweinitz’s sunflower or small whorled pogonia? Further project information will
be needed during permitting in order to satisfy the SLOPES procedures for the Northern long-
eared bat, including estimated area of tree clearing and whether percussive activities will be a part
of the project. Feel free to coordinate with me as you get closer to PCN submittal. Response: There had not been any further coordination with the USFWS beyond the prospectus/public notice as there were no comments from USFWS on the Grassy Creek Tributaries mitigation project. USFWS did not provide any comments on the draft mitigation plan either. On August 21, 2019 in response to the same comment on Toms Creek, WLS contacted USFWS to see if there was any further coordination needed on the project regarding potential presence for Schweinitz’s sunflower or small whorled pogonia. On August 29, 2019 USFWS responded with additional questions and WLS responded on August 30th, 2019 (Steve Kichefski was copied on this email). WLS is waiting on a response email from USFWS. WLS has not observed any protected species or potential suitable habitat for protected species during project evaluations conducted during optimal survey windows. Also, on the IPAC website there is no critical habitat in the project area. The response from USFWS will be forwarded to the USACE and any further coordination from USFWS will be conducted. WLS will coordinate with the USACE on the SLOPES procedures for the Northern long-eared bat regarding the PCN submittal. The project is not near any known hibernation/maternity sites, nor is Surry County listed as a county for confirmed hibernation/maternity sites. WLS has also reached out to USFWS regarding the NLEB for this project. On the IPAC website the NLEB 4(d) rule determination key had an outcome of ‘may affect’ due to the tree cutting. On August 21st, 2019 WLS also reached out to the USACE to determine next steps regarding the NLEB.
4. Section 6.3 (p41/42): Section 3.9.3: Although culverts/fords were shown on the plans, make sure
the existing culvert locations are depicted on the existing conditions Figure 7. Also, in the existing
condition section of the written portion of the draft plan, provide a summary of the current
crossing type, size and condition (is it functioning, perched, etc.?). In the Mitigation Work Plan,
include a description of whether the crossings will be removed, replaced, etc. Justify why the extra
crossings are needed on R1 and between R2/R3? Response: The existing culvert locations and information have been added to Figure 7 as well as additional language describing the crossing type and pipe size/condition in the corresponding Section 3.6.2 Existing Reach Descriptions. Additional language has been added in Section 6.2.1 Stream Design Reach Summaries, that describes any improvements or changes to the existing crossings. On Figure 10 in the draft mitigation plan there were two crossings proposed on R1; now there is only one culvert crossing and it is an existing powerline easement break as well. The crossing between R2/R3 is an existing ford crossing that is being repaired. The crossing on R3
is a 20’ proposed ford crossing to allow access between pastures. All the crossings for this project are so the landowner can continue his current farm operation and allow access between pastures.
5. Section 6.2.2 (p37): Please explain what was meant by the intent to “satisfy the final
performance standard for generating riparian buffer mitigation credits.” Is buffer credit also being
sought for this project? Planting list seems weighted towards the weedier successional species
rather than the more reference climax species for bottomland hardwood and the dry mesic oak
hickory forest. Response: No riparian buffer credits are being proposed for this project and the statement has been removed from Section 6.2.2, pg 37. We have updated the secondary target community as Mesic Mixed Hardwood Forest (Piedmont Subtype) and updated Section 6.2.2 proposed planting list and the vegetation planting plan sheets accordingly.
6. Add footnote about 10% credit reserve for bankfull events to Table 12 per Todd Bowers
comment in the initial evaluation. Response: The footnote has been added to Table 12.
7. Section 6.6: I like the use of and description of the Water Quality Treatment Features. Response: WLS appreciates the comment as we expect the water quality treatment features to improve overall downstream hydrology and function as compared to the current conditions. As discussed during the IRT site visit and mitigation plan, the water quality improvement features will be installed to provide a WQ benefit as they will increase infiltration and groundwater recharge, allow nutrient uptake within the riparian buffer areas, and reduce storm flow energies rather than a rapid flush under current conditions.
8. Section 8.1 (pg 49): Explain or remove the statement that, “At least two bankfull events must
occur in separate years.” Several other locations in the draft plan reference the appropriate
standard of four separate bankfull events occurring in separate years as written in the October 24,
2016 guidance. Response: Revised language in Section 8.1 Stream Hydrology monitoring states: “Four (4) separate bankfull or over bank events must be documented within the seven-year monitoring period and the stream hydrology monitoring will continue until four (4) bankfull events have been documented in separate years. In the event that less than four bankfull events occur during the monitoring period, release of these reserve credits is at the discretion of the IRT.”
9. Section 9: Overall good description of Monitoring. Response: WLS appreciates the comment as we intend to follow the IRT guidance as appropriate for each mitigation project.
10. Depict proposed crest gage/transducers/photo points/well locations/etc. on appropriate
figures or add a monitoring figure if Figure 10 gets too busy. Response: WLS has added Figure 11 with the corresponding Proposed Monitoring Features.
11. The Corps wants to ensure that the appropriate money is being provided to fund the long term
endowment in perpetuity for annual site monitoring/reporting/encroachment resolution. Verify
that the estimated 5 billed hours annually is enough to appropriately monitor the mitigation
easement including, “file review, travel time, on site time, post visit report production” as
submitted in the Unique Places to Save acceptance letter. This estimate seems low considering
driving time alone. Response: WLS solicited input from Unique Places to Save (UP2S) regarding the USACE comments/questions. UP2S responded to WLS that they spoke with USACE/Steve Kichefski on August 22nd, 2019 regarding this comment for Toms Creek and as a result the billed hours have been increased to 7 hours and the mileage has been increased annually for both Grassy and Toms Creek. The travel time was initially calculated when UP2S considered the site monitoring of other easements nearby on the same trip. As of 3 months ago they no longer make this consideration and the Grassy Creek Tributaries mitigation project is now being treated this way, which increases the total endowment to $43,457.14 (for additional hours and mileage). Violation areas addressed by staff initially, then if needed, move on to mediation conducted by an attorney or mediation expert. If a violation extends to possible court proceedings, then UP2S will hire an attorney or team of attorneys to represent their interests. Also, UP2S combines their endowment proceeds and uses the power of a larger fund to help defend their easements. They do not have separate investment funds/legal funds for each easement, and this is a
common practice of land trusts to pool their stewardship and legal defense funds. Also, UP2S will be participating in the Terra Firma insurance program with LTS to help insure their easements for legal defense purposes, thereby taking some pressure off their endowment funds.
12. Make sure any wetland impacts associated with the project such as stream channel excavation
and adjacent stream bank construction or drainage are accounted for in the PCN submittal. Response: All wetland impacts associated with the proposed activities such as stream channel excavation and adjacent stream bank construction and drainage manipulation/filling will be shown on a wetland impacts figure and described further in the PCN submittal. WLS does not anticipate any wetland impacts associated with this project.
13. Will the existing substrate material in the abandoned stream channels be utilized for the new
channel locations? I did not see it mentioned in the draft plan. Response: We added language in Section 6.7.2 that “whenever possible existing substrate material in the abandoned stream channels be harvested and utilized for the new channel locations.”
14. What is the Pilot Mountain State Park grant submittal status? If approved, how will its timing
change the Grassy Creek project timing/construction? If not approved, further review for the
project design and reaches may be needed. Did the Pilot Mountain State Park grant request include
the intermittent stream section upstream of the R2 reach in the park? Response: Please see DWR response comment #11. WLS submitted grant applications to both the NC Clean Water Management Trust Fund (CWMTF) and NC DWR in Spring 2019 for the proposed stream restoration activities within the Pilot Mountain State Park (Park) property. At the time of this comment response letter, both applications have been reviewed and scored favorably as compared to similar projects submitted in that round. Per CWMTF and DWR, we anticipate project review decisions by mid-October and will notify the USACE/IRT of the grant approval status and any potential design changes immediately upon notification. WLS understands that if the grant application and proposed stream restoration activities within the Park are approved, that further IRT review may be required for upper R2 intermittent section and transitional areas. WLS removed this approximate 500 LF section (previously named R3) from the draft mitigation plan due to IRT concern with reach fragmentation. As described in the final mitigation plan and shown on the design plan sheets, the proposed design profile and hydrologic & hydraulic modeling for reaches R1 and R2 currently tie into the existing channel elevations. The project/construction timing for the mitigation site is anticipated to begin early winter and site planting completion by spring 2020. Any design changes as a result of the Park project approval will be incorporated into the transition/tie in locations to ensure channel stability and overall project success.
15. The credit ratio proposed for R4 is higher than discussed at the initial acceptance and the site
visit. Little work is being done in the area and no planting, provide further justification of the ratio
proposed. Response: Please see DWR comment response #10. Please contact me if you have any additional questions or comments. Sincerely,
Water & Land Solutions, LLC
Kayne M. Van Stell Vice President, Ecosystem Design Services Water and Land Solutions, LLC Mobile Phone: [phone]