FW: [External] RE: REVISED Draft Mitigation Plan Review Comments/ RES Cape Fear 02 UMB - Tobacco Road Mitigation Site/ SAW-2021-00489/ Alamance County

Baker, Caroline D
From: Homewood, Sue
Sent: Friday, March 3, 2023 8:43 AM
To: Baker, Caroline D
Subject: FW: [External] RE: REVISED Draft Mitigation Plan Review Comments/ RES Cape Fear 02
UMB - Tobacco Road Mitigation Site/ SAW-2021-00489/ Alamance County
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DW R#: 20210536
Doc Date: 03/02/23
Doc Type: Mitigation — Mitigation Information
Doc Name: General topic of email title
Thanks,
Sue Homewood (she/her/hers)
401 & Buffer Permitting Branch
Division of Water Resources
Sue. [e-mail]
336 813 1863 mobile
919-707-3679 office *new*
Email correspondence to and from this address is subject to the
North Carolina Public Records Law and may be disclosed to third parties.
From: Isenhour, Kimberly T CIV USARMY CESAW (USA) <[e-mail]>
Sent: Thursday, March 2, 2023 4:29 PM
To: Benton Carroll <[e-mail]>
Cc: Jamey Mceachran <[e-mail]>; Tugwell, Todd J CIV USARMY CESAW (US)
<[e-mail]>; Bowers, Todd <[e-mail]>; Davis, Erin B CIV USARMY CESAW (USA)
<[e-mail]>; Haywood, Casey M CIV USARMY CESAW (USA) <[e-mail]>;
Wilson, Travis W. <[e-mail]>; Merritt, Katie <[e-mail]>;
[e-mail]; Munzer, Olivia <[e-mail]>; Haupt, Mac <[e-mail]>;
Homewood, Sue <[e-mail]>
Subject: [External] RE: REVISED Draft Mitigation Plan Review Comments/ RES Cape Fear 02 UMB - Tobacco Road
Mitigation Site/ SAW-2021-00489/ Alamance County
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Hi Ben,
I discussed this with the IRT, and would offer the following comments:
1. We disagree that it is impossible to measure an increase in overbank event frequency over the monitoring
period. For any project that is designed to reconnect the stream to its floodplain, gauges should be installed to
track the frequency and duration of overbank events (preferably pressure transducers). Automated photo

loggers may also be used; however, given that this is an experimental situation, we will require a pressure
transducer in addition to the flow cameras.
2. In a slate belt or coarse bed material stream there is concern that lack of flow or piping through the structure
will eventually result in failure of the structure. Additional photo points should be added to these areas.
3. There is continued concern regarding the long-term viability of these structures and constraints to aquatic
passage.
4. Your email below references Reaches TC1-C and D, but it looks like the figure you attached has them labeled as
TR1-C and D. Please update for consistency.
5. If you elect to install these layered riffles, we will require additional cross -sectional monitoring on these two
reaches that includes both the layered riffles and pools.
6. If annual cross -sectional monitoring efforts demonstrate channel, bank or bed instability, a longitudinal profile
may be required prior to close-out.
7. The performance standard proposed needs to be reworded to address overbank flows/floodplain connectivity
specific to these reaches (via gauges) and demonstrate the projected uplift (i.e., enhanced wetland hydrology).
8. Based on the concerns above, we do not agree with the proposed credit release for the 1874.334 SMUs
associated with these reaches. If I understand the proposed credit release correctly, Years 5 and 7 will receive
187.454 SMUs and Year 6 will receive 93.717 SMUs from Reaches TC1-C & D, so you are only holding credits
from these two reaches during monitoring years 0-4, and if you meet the layered riffle standard in monitoring
year 5, the remaining 1405.751 credits would be released?
a. The IRT is amenable to the proposed Year 5-7 release; however, the layered riffle standard will not be
released until year 7, assuming the layered riffle standard has been met.
b. Please submit a revised proposed credit release schedule and layered riffle performance standard based
on the comments above, prior to submitting the final mitigation plan.
Please reach out if you would like to discuss further.
Regards,
Kim
Kim Isenhour
Mitigation Project Manager, Regulatory Division I U.S. Army Corps of Engineers 1 919.946.5107
From: Benton Carroll <[e-mail]>
Sent: Tuesday, February 14, 2023 4:04 PM
To: Isenhour, Kimberly T CIV USARMY CESAW (USA) <[e-mail]>
Cc: Jamey Mceachran <*[e-mail]>
Subject: [URL Verdict: Neutral][Non-DoD Source] RE: REVISED Draft Mitigation Plan Review Comments/ RES Cape Fear
02 UMB -Tobacco Road Mitigation Site/ SAW-2021-00489/ Orange County
K i m,
After reviewing the comments I wanted to follow up on your comment #1. RES understands that this is a new approach
and that comes with uncertainty based on your comment I would like to propose the following layer riffle performance
standard:
Layered Riffle performance standards include raised baseflow elevations and increased overbank-event frequency. These
will be measured using flow cameras, installed prior to construction in order to capture pre- and post -construction
conditions. In order to demonstrate increased baseflow elevations, recorded flow days over layered riffles must be
greater than or equal to 90% of the flow days observed for Reach TC1-e for four years. Otherwise, stream monitoring will
continue until four years of flow over layered riffles at this performance standard have been documented. Accurately
measuring an increase in overbank-event frequency over a few months or years is not possible, therefore, RES suggests
that if the baseflow elevation standard is met, then overbank flow event criteria has also been met, as an increase in
baseflow elevation confirms a decrease in channel flow capacity and a resulting increase in overbank flow events.
Credits for Reaches TC1-C and D will not be released until this performance standard is met.

Reaches TC1-C and D (include layered riffles) as Enhancement I make up an estimated 1874.334 SMUs. The attached
credit release table demonstrates RES expectation for when these credits would be released, assuming the performance
standard is met in 4 years. I also attached a concept map for your reference. Please let me know if you are agreeable
with this approach so that RES can move forward with the Final Mitigation Plan.
Thanks,
Ben Carroll, PE
Engineer
RES I res.us
Direct: 919.209.1077 Mobile: [phone]
-----Original Message -----
From: Isenhour, Kimberly T CIV USARMY CESAW (USA) [e-mail]
Sent: Friday, February 3, 2023 6:10 PM
To: Jamey Mceachran [e-mail]
Cc: Benton Carroll [e-mail]; Tugwell, Todd J CIV USARMY CESAW (USA) [e-mail];
Haywood, Casey M CIV USARMY CESAW (USA) [e-mail]; Davis, Erin B [e-mail];
Wilson, Travis W. [e-mail]; Bowers, Todd [e-mail]; Matthews, Kathryn
(kathryn [e-mail]) kathryn [e-mail]; Munzer, Olivia [e-mail]; Crumbley,
Tyler A CIV USARMY CESAW (USA) [e-mail]; Davis, Erin B CIV USARMY CESAW (USA)
[e-mail]
Subject: [EXTERNAL] REVISED Draft Mitigation Plan Review Comments/ RES Cape Fear 02 UMB -Tobacco Road
Mitigation Site/ SAW-2021-00489/ Alamance County
Jamey,
Attached are the RES Cape Fear 02, Tobacco Road Mitigation Site, Revised Draft Mitigation Plan IRT comments. You may
proceed with developing the final mitigation plan for the above referenced mitigation site provided you adequately
address all comments/concerns in the enclosed memo. As you are preparing the Final Instrument and Mitigation Plan,
please feel free to contact me with questions regarding the comments. When the Final Mitigation Plan is complete,
please upload an electronic copy of the complete document to RIBITS for distribution to the IRT and notify me. In
addition, please submit your Nationwide Permit 27 application for review and approval prior to discharging fill material
into waters of the United States. *Please let me know when the ePCN has been submitted so that it is not circulated to
the Raleigh Regulatory Field Office staff.
Feel free to reach out with any questions.
Regards,
Kim
Kim Isenhour
Mitigation Project Manager, Regulatory Division I U.S. Army Corps of Engineers 1 919.946.5107