20140762 Ver 4_RE R-2915D Site 6_20180828

Wanucha, Dave
From: Wanucha, Dave
Sent: Tuesday, August 28, 2018 9:29 AM
To: Slaughter, Johnathan H; Steve Kichefski
Cc: Beaver, G Trent
Subject: RE: R-2915D, Site 6
Have we determined whether or not aquatic passage is an issue at this location? I cannot find in the Merger minutes where it
was discussed and it is not stated on the plans. Another issue is that the permit application and Public Notice stated that the
rock cross vane at Site 6 would be installed for Avoidance and Minimization. Not sure if that is an obstacle or not, Steve would
need to weigh-in on that. If we can determine that passage is not an issue, I think that sort of paves the way for DOT to do what
it needs to do to stabilize the outlet in terms of minimizing downstream scour and stabilizing the structure itself (if needed). If
passage is required at Site 6, then DOT needs to engineer ways to ensure passage is maintained in addition to stabilizing the
outlet and minimizing downstream scour by using some other type of energy dissipater/plunge pool structure.
Dave Wanucha
Division of Water Resources
Transportation Permitting Unit
NC Department of Environmental Quality
336-776-9703 office
336-403-5655 mobile
[e-mail]
NC DEQ Winston Salem Regional Office
450 West Hanes Mill Road, Suite 300
Winston Salem, NC 27105
a������ �������,��:s���������� �� ����� ������ ��`��,� ����:����,�,� �,� ,�������� �� ��`��
�V����� �°��������� ��.����� ��������,� ��W�r ����:� a���.� �� ���,����,���� �� �������� �s�����,�.
From: Slaughter, Johnathan H
Sent: Monday, August 27, 2018 11:08 AM
To: Steve Kichefski <[e-mail]>; Wanucha, Dave <[e-mail]>
Cc: Beaver, G Trent <[e-mail]>
Subject: R-2915D, Site 6
Guys,
I just spoke with the hydraulic engineer from Sungate, Henry Wells, regarding the rock vane shown on the plans at site 6. As you
recall we eliminated this structure because we saw no benefit.
According to Henry, the rock vane was not shown in the initial CSR but was added later, presumably after a request was made
during a concurrence meeting. The rock vane wasn't needed for a hydraulic reason. Initially, we installed the class II riprap in
the plunge pool and that held up well. Later it was determined that one of the pipes had separated, which we
repaired/sealed. Additional rock was added to the rock lined plunge pool to protect against additional scour under the end wall
footer. That rock was displaced by storm events because we had essentially eliminated the energy dissipating plunge pool.
At this point, my recommendation is to remove the additional rock that was added while leaving the class II in the bottom of the
pool as shown on the plans. It DOT engineers have concerns about the structure settling further, we should probably dewater,

form up and pump concrete under the footer to fill the voids and create a more permanent fix to the issue. We also need to add
about 10 feet of class II on the far bank as we discussed in the field.
Are you agreeable to this proposal?
I!Irr�7ail �;urre,�l�ui�dc,i��:e, C�u ai�d ��ruir7 U•ii� �ci�dcr i� �ul����;�E� �C�u U•ic, I"J,�, I ul�li�; I'�Ee,�;ur;� I...aw ai�d rr�7ay I�c rll��:lu�crl �C�u �C�h•ih�rl I�artle,�,