20150998 Ver 4_Modifications_20181019

Strickland, Bev
From: Cahoon, Steve <[e-mail]>
Sent: Friday, October 19, 2018 3:18 PM
To: Reusch, Eric G CIV USARMY CESAW (US); Higgins, Karen
Subject: [External] Duke Energy's Sutton Energy Complex - Emergency Repairs
Attachments: Sutton_Repair_Package_10192018.pdf
Good Afternoon,
As we have discussed, please find attached to this email information regarding several emergency repairs that have
taken place at the Sutton Energy Complex, specifically the cooling lake, in the wake of Hurricane Florence. The
information supplied in the application package, follows the information requested by the Corps in its September 10,
2018, memorandum detailing emergency permitting procedures.
Duke Energy has made the following emergency repairs to eliminate water from flowing out of the lake due to dam
breaches caused by the excessive rainfall from Hurricane Florence.
1) Constructed a Second Weir (Weir B) to isolate the largest breach (Breach 2), (Weir A previously permitted
SAW -2018-01861)
2) Temporary Repairs of Breach 1
3) Temporary Repairs of Breach 3
Permanent repairs to these breach areas, once designed, will be submitted to the Corps and DWR for permitting under
the normal permit process.
If you have any questions or need additional information, please contact me.
Steve Cahoon
Duke Energy
EHS — CCP Permitting and Compliance
Office - [phone]
Cell - [phone]
[e-mail]

Hurricane Florence made landfall in Wilmington, NC on Friday, September 14, 2018 and lasted
through Monday September 17, 2018. Over 26 inches of rain fell in Wilmington during
Hurricane Florence which caused flooding throughout the eastern North Carolina region.
Beginning on Thursday, September 20, 2018, three breaches and one area of slope movement
occurred at the Sutton Lake Dam at the Duke LV Sutton Energy Complex.
Duke Energy and our sub -consultants began engineering support for the Emergency Temporary
Repairs on Friday, September 21, 2018. Initial Emergency Temporary Repairs were completed
by Saturday, September 29, 2018. Additional temporary repairs began on October 12, 2018
and completed on October 16, 2018. The three Emergency Temporary Repairs included
rebuilding the dam for Breach 1, two (A and B) Emergency Weirs in the intake canal to keep
water from flowing through Breach 2 (Weir A previously permitted [SAW -2018-01861]), and to
rebuild the dam at Breach 3. Volumes of fill used for the breaches are estimates gathered in
the field before surveyors visited the site. Planning and design for permanent repairs to the
Sutton Lake Dam are currently underway.
1) Name of Responsible Party - Duke Energy Progress LLC
Bill Forster [phone]
2) Work Description — Breach 1 Repair
a. Construct a rock emergency dam to match the original dimensions of the dam prior
to Hurricane Florence to keep the water in Sutton Lake from flowing into the Cape
Fear River. Began construction of emergency dam repair at Breach 1 on 9/27/18
and was completed on 9/29/18.
b. Project used dump trucks and heavy equipment to place #4 stone, rip rap, Bin
Blocks, Super Sacks and Dura Skrim to construct a 255 -foot long dam repair that is
trapezoidal in shape and larger at the base with approximately 1,723 cubic yards of
material placed below the ordinary high water mark (OHWM).
c. Dredging —No dredging was performed.
d. Filling of Wetlands — No wetland areas were filled; fill placed only in open waters.
e. Please see the attached vicinity map.
f. Please see the attached plan view and cross section drawing.
3) Work Description — Breach 2 Repair— Weir B
The repair activity described below is designed to isolate Breach 2, thereby allowing a
permanent repair solution to be developed and to facilitate that repair once developed.
In addition, the upland area between the Cape Fear River and Breach 2 is being
reclaimed.
a. Construct a 6 foot sand and rock emergency weir (Weir B) within the intake canal
south of Breach 2 and Weir A to help isolate Sutton Lake from the Cape Fear River
Breach 2. Construction of Weir B began and was completed on 10/12/18.

b. Project used dump trucks and heavy equipment to place sand, #57 stone and
geotextile to construct a 130 foot long, 6 foot high and 15 foot wide plug (at the
top), the weir is trapezoidal in shape and larger at the base. There was
approximately 650 cubic yards of material placed below the OHWM. The weir will
be removed after the permanent repair to the Breach 2 is completed.
c. Dredging —No dredging was performed.
d. Filling of Wetlands —No wetland areas were filled; fill placed only in open waters.
e. Please see the attached vicinity map.
f. Please see the attached plan view and cross section drawing.
4) Work Description — Breach 3 Repair
a. Construct a rock emergency dam to match the original dimensions of the dam prior
to Hurricane Florence to keep the Cape Fear River from flowing into Lake Sutton.
Initial construction of the emergency dam repair at Breach 3 began on 9/27/18 and
was completed on 9/29/18. Initial emergency repairs did stop the Cape Fear River
from flowing into the lake, but did not stop Sutton Lake from flowing into the river.
Hence, 170 Super Sacks were placed on the Sutton Lake side of the dam on
10/15/18 and 10/16/18 to better secure the Dura Skrim and solidify the breach
repair.
b. Project used dump trucks and heavy equipment to place #4 stone, rip rap, Bin
Blocks, Super Sacks and Dura Skrim to construct a 280 -foot long dam repair that is
trapezoidal in shape and larger at the base with approximately 1,873 cubic yards of
material placed below the OHWM.
c. Dredging— No dredging will be performed.
d. Filling of Wetlands —No wetlands were filled; fill placed only into open water.
e. Please see the attached vicinity map.
f. Please see the attached plan view and cross section drawing.
5) Duke Energy will:
a. Provide any mitigation required by the Corps of Engineers;
b. Duke Energy will perform all work in a manner that would avoid and minimize
impacts to waters of the US, including wetlands to the maximum extent practical;
c. All work will cease should historic or cultural resources be discovered and the Corps
and the State Historic Preservation Officer would be immediately notified;
d. No impacts will occur to threatened or endangered species due to this work;
e. All work will be done in an expeditious manner; and
f. There are no areas of temporary fill associated with the project.

BREACH 1
Cape Fear River
15 ft Dike -.Crest
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
- - - - - - - - - - - - - - - - - -
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Cooling Pond
Approximate/Assumed Breach Limits
- 259 ft
IF
Dike Crest
Cooling Pond 15 ft 10 Cape Fear River 10
HDPE/LDPE
Liner (If needed)
�1 Repair Material
Normal Pool (From Temporary Plug)
3'
Cooling Pond
Approximate/Assumed Breach Limits
wood COOLING POND MINOR BREACH 1
LEGEND: E-ironment& ff—tr�d—S.�tim.
*NOTE: REFERENCE ONLY. NOT TO SCALE. w„nom P W L.V. SUTTON ENERGY COMPLEX
DUKE SCALE: AS SHOWN DRAWN BY: JAH
ENERGY. JOB NO: 7812180050
DATE: 10/09/2018 CHECKED BY: ---

AL
EMERGENCY WEIR B
Towards Cooling Pond
15 ft
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Canal
Approximate/Assumed Breach Limits
130 ft
IF
Emergency Weir
� �
4 15 ft Canal (Away From Cooling Pond) Towards Cooling Pond 10
3/1
6 ft
wood COOLING POND EMERGENCY WEIR B
LEGEND: Envl,onment&1nfr,,t,, ,m S,1,fi,n,
*NOTE: REFERENCE ONLY. NOT TO SCALE. w„nom P W L.V. SUTTON ENERGY COMPLEX
DUKE SCALE: AS SHOWN DRAWN BY: JAH
��ENERGY. JOB NO: 7812180050
DATE: 10/09/2018 CHECKED BY: ---

15ft
5'x5'x3' Sandbags
4 Cooling Pond
Normal Pool
3'
Cooling Pond
Lake Bottom
LEGEND:
HDPE/LDPE
Liner (If needed)
Dike Crest
4- 15 ft 10
5'x5'x3' Sandbags
Repair Material
(From Temporary Plug)
BREACH 3
- 280 ft
Cape Fear River 10
Approximate/Assumed Breach Limits
"NOTE: REFERENCE ONLY. NOT TO SCALE.
Ak
Cape Fear River
Cooling Pond
IF
wood
COOLING POND MINOR BREACH 3
Environment S Inf—crud— Solutions
w„n�P �W
L.V. SUTTON ENERGY COMPLEX
DUKE
SCALE: AS SHOWN
NO: 7812180050
DRAWN BY: JAH
ENERGY,
DATE
DATE: 10/16/2018
CHECKED BY: ---

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