DWR Comments DMS Oak Hill Dairy As-built Review

Baker, Caroline D
From: Davis, Erin B
Sent: Tuesday, January 10, 2023 10:29 AM
To: Baker, Caroline D
Subject: FW: DWR Comments - DMS Oak Hill Dairy As -built Review
Laserfiche Upload: Email
DWR#: 20190863 v.1
Doc Date: 7/7/22
Doc Type: Mitigation — Mitigation Information
Doc Name: General topic of email title
From: Davis, Erin B
Sent: Thursday, July 7, 2022 11:43 AM
To: Browning, Kimberly D CIV USARMY CESAW (US) ([e-mail])
<[e-mail]>
Cc: Tugwell, Todd J CIV USARMY CESAW (US) ([e-mail]) <[e-mail]>;
Wilson, Travis W. <[e-mail]>; Munzer, Olivia <[e-mail]>; Bowers, Todd
([e-mail]) <[e-mail]>
Subject: DWR Comments - DMS Oak Hill Dairy As -built Review
K i m,
Below please find DWR's comments on the DIMS Oak Hill Dairy As-built/MYO Report. Please let me know if you want to
discuss anything.
1. The redline sheet 1.6 does not callout any changes to the driveway pipe, which is shown to end prior to the
limits of disturbance (LOD) line outside of the easement. However, the as -built sheet 6 of 23 shows this pipe
extending through the LOD line and the top of bank (TB) line to end right on the easement line within the stream
channel. DWR is concerned with this direct discharge into the restored stream and that this change wasn't called
out in the redline plans. Looking back at the approved mitigation design drawings sheet 6.3, this pipe should've
discharged to a graded swale prior to reaching the restored stream channel. Please confirm this construction
change and provide a justification. Since the pipe appears to end on the CE line, what is the risk that the
easement could be affected by future structure maintenance?
2. DWR requests any areas of standing water located within proposed wetland credit areas be shown on the CCPV
figures. Please monitor all standing water areas not planted during construction for potential inclusion in a
future supplemental planting effort with OBL/FACW woody species (including live stakes or whips).
3. It appears multiple rock structures were replaced by log structures along UT1A to enhance diversity, which DWR
can appreciate. But given that log structures can rot, are there any long-term stability concerns with grade
control due to the steepness of the channel? Were footer logs installed for each log sill?
4. DWR requests that the new stabilized outlet channel shown on redline sheet 1.6 be added to the MY1 CCPV
figure. Are there any concerns that this new channel could have a drainage effect on the adjacent wetland
creation area?
5. DWR requests that the floodplain ditch shown in photos PP26 and PP27 be added to the MY1 CCPV figure.
6. Based on the photo, the BMP step pool is functioning as designed. Has an initial cleaning out of the trapped
sediment from construction/MY1 been considered as a way to increase capacity to trap additional sediment in
the future?

7. DWR appreciates the recognition callout that some pools were filled at the time of the as -built survey. Please
note in the MY1 report if this sediment has flushed through the system and/or which pools continue to be filled
in.
8. DWR was glad to read that invasives were treated during construction. We are particularly concerned with the
monitoring and management of bamboo, kudzu and Japanese knotweed in and/or bordering this site.
DWR is ok with the proposed credit release.
Many thanks,
Erin B. Davis, PWS
Stream & Wetland Mitigation Coordinator
401 & Buffer Permitting Branch
Division of Water Resources
Department of Environmental Quality
919-817-0360 cell
[e-mail]