Loading...
HomeMy WebLinkAbout20181097 Ver 1_DTA Photomap_20191028Strickland, Bev From: Katie Webber <kwebber@res.us> Sent: Monday, October 28, 2019 3:20 PM To: Haupt, Mac; Davis, Erin B Cc: Steve Kichefski; Bradley Breslow; Benton Carroll; Tugwell, Todd J CIV USARMY CESAW (US); Kim Browning; Frasier Mullen Subject: RE: [External] A question on Dogtown Mitigation Plan revisions Attachments: DTA Photomap.pdf Follow Up Flag: Follow up Flag Status: Flagged 8 External email. Do not click links or open attachments unless you verify. Send all suspicious email as an attachment to Mac, Thank you for your call and follow up email. I appreciate your review in advance of the final. I talked to Frasier, our senior stream designer, about this stream through this section of wetlands and she was able to clarify what exactly is going on here. I was wrong about the feature having any pond characteristics. There is actually a bank of cut fill around the pond downstream that the reach drains into that is backing up water and sediment; there is a small drainage channel cut through there as well but overall the area is swampy. Despite that, there is a clear channel in the DT2A E2 area where water is preferentially flowing. At the point that the channel gets weak near the bottom of this reach, we pick up restoration. Once we restore this feature, we should get sediment moving through the system again. To support your review, I compiled a PDF of a few photos that we have of the area. The red boxes represent where the photographer stood when the photo was taken, with the arrow showing the depth and direction of field. Sorry I wasn't quite as up to speed as I should have been when you called, but thanks for bearing with me while I learn about our projects here. Thank you again and if you have any more questions or follow up please do not hesitate to ask. Katie From: Haupt, Mac <mac.haupt@ncdenr.gov> Sent: Monday, October 28, 2019 1:33 PM To: Katie Webber <kwebber@res.us>; Davis, Erin B <erin.davis@ncdenr.gov> Cc: Steve Kichefski <Steven.I.kichefski@usace.army.mil>; Bradley Breslow <bbreslow@res.us>; Benton Carroll <bcarroll@res.us>; Tugwell, Todd J CIV USARMY CESAW (US) <Todd.J.Tugwell@usace.army.mil>; Kim Browning <Kimberly.D.Browning@usace.army.mil> Subject: [EXTERNAL] RE: [External] A question on Dogtown Mitigation Plan revisions Katie, After looking at your proposed changes and speaking with you on the phone I am ok with what you folks propose. However, I will point out that it appears from station 1+75 to station 4+50 it appears the channel feature goes through wetlands. If this is the case, and it may be related to an old pond bed (as Katie pointed out on the phone), we are concerned that the feature will not maintain channel -like characteristics. Sorry it took me awhile to get to this. If you have any further questions or comments, give me a call or email. Thanks, Mac From: Katie Webber [mailto:kwebber@res.us] Sent: Tuesday, October 15, 2019 9:36 AM To: Davis, Erin B <erin.davis@ncdenr.gov>; Haupt, Mac <mac.haupt@ncdenr.gov> Cc: Steve Kichefski <Steven.I.kichefski@usace.army.mil>; Bradley Breslow <bbreslow@res.us>; Benton Carroll <bcarroll@res.us> Subject: [External] A question on Dogtown Mitigation Plan revisions External email. Do not click links or open attachments unless you verify. Send all suspicious email as an attachment to report.spam@nc.gov Good morning, We are working on providing comment responses and a final mitigation plan on the Dogtown Stream Mitigation Project, and we wanted to check in with you on one of the items before we submit. You provided the following comment regarding DT2: "Design sheet S5 shows reach DT2 as Enhancement 1. However, virtually no work is being performed except for at the end of the reach. DWR suggest that this reach be a different ratio, and should likely be measuring credit through valley length versus stream centerline since it appears no definitive stream channel may exist." In response, we reviewed the DT2 design and generally agreed that a blanket Enhancement I crediting approach was not justified. We decided to split DT2 into A and B reaches to allow for a more detailed crediting approach. Reach DT2-A (Plan Sheet S5), will be the reach originally named DT2, and DT2-B (Plan Sheet S6) will be the reach that originates in the power easement. The work proposed in the upstream section of DT2-A is outside of the jurisdictional limits of the existing stream, and the majority of proposed work in DT2-B will occur within an existing power line easement. Therefore, no credit will be received for these areas despite the work we propose. To compensate for this work, we are proposing to receive Enhancement II credit (2.5:1) for the length of the reach between the upstream and downstream restoration areas on the DT2-A reach. We expect that the work proposed on the headwaters of both reaches will reduce the sediment load in DT2-A bringing it closer to an equilibrium with sediment transport capacity. We are now claiming restoration on the downstream portion of DT2-A where we are plugging the diversion channel and restoring flow through the valley into the existing pond bottom. This approach will improve the sediment transport capacity of DT2-A which will promote stable channel dynamics upstream of the proposed restoration. Channel alignments through the enhancement sections of DT2-A and B were taken from surveyed thalweg provided by a licensed surveyor. We anticipated this channel alignment to become increasingly defined once reach sediment transport is restored. For these reasons we feel that the current alignment for the enhancement sections is justified. We have attached our proposed revised channel design for DT2 and would like it if you would review it in advance of our resubmission. Please advise us if you consider this a balanced approach to this stream reach. Thank you, Katie Webber, LPSS, CPSS Project Manager RES I res.us Direct: 540.905.4388 1 Cell: 410.279.5741 2 U m CL U) C7 w Er w a z pres 302 Jefferson Street, Suite 110 Raleigh, NC 27605 Main: 919.829.9909 www.res.us Engineering Services Provided By: Angler Environmental, LLC License: F-1428 SEAL FULL SCALE: 1"=30 0 30 60 2" = FULL SCALE 1 " = HALF SCALE I` 0 N w H Q o H O J fl z _O U H C/) z O U O IL O z fr } o Q o z o � (n W J w > w —j w fr w Q z 0 U F- � � N 0 0 z = Q U LLJ Z w VJ O U z w O m J I— z v Q H Q z w Q U Q o fY fY fz o PROJECT NUMBER: 0383 PROJECT MANAGER: KAW DESIGNED: BRC DRAWN: TRS CHECKED: AFM SHEET NUMBER: S5 { � •, � � ..1_w ' i try �; x.; , ��� � � o- ?� , Im .�. tip~• .� �'�.+ # - � - • .'� � �I +���� ..�� t>r`. r'F, _ KM . ' OIL • . � � �'M"L��.l fir. � �,- • ''-y F'' �+ C� . PIM _ � i,ii F .5• 1 r'r�#e3 �.. � i . :ix' �±�a' • .�'t0.�•'� {•i'-' '• ^+ �p••r � 'S:- � 7Y '+ !i Ma 116 T - Ou ' '� •�`. � +' �=.• y �T ._ �~� __ �� - �• � ice' �, � � ,•.rt.". ..r .� ',%may .'�', � � -