20030179 Ver 6_Monitoring Report_20090102

Pk Duke
Energy®
Carolinas
HYDRO STRATEGY & LICENSING
Duke Energy Carolinas, LLC
EC12Y/526 South Church Street
Charlotte, NC 28202-1802
Mailing Address:
EC12Y/P.O. Box 1006
Charlotte, NC 28201-1006
December 23, 2008
Mr. John Dorney
NC Division of Water Quality
1617 Mail Service Center
Raleigh, NC 27699-1617

Subject: Dillsboro Hydroelectric Project's November Water Quality Monitoring Report
Mr. Dorney:
Enclosed is the November pre-dam removal water quality monitoring report for the Dillsboro
Project. These data are provided per the 401 Water Quality Certification with Additional
Comments dated November 21, 2007. If you have questions regarding this report, please do not
hesitate to give me a call at 704/382-0805.
Sincerely,
I
4,,.k-
D. Hugh Barwick
Senior Environmental Resource Manager
Enclosure: Report
D
AN 2 2009
U64h - A'Al ER UUALITY
WETLANDS AND STORAIAiATER BRANCH
r

DILLSBORO HYDROELECTRIC PROJECT
(FERC No. 2602)
NOVEMBER 2008 WATER QUALITY REPORT
Prepared for:
DUKE ENERGY CAROLINAS, LLC
Charlotte, North Carolina
Prepared by:
DEVINE TARBELL & ASSOCIATES, INC.
Charlotte, North Carolina
DECEMBER 2008

Devine Tarbell & Associates, Inc.
Consulting Engineers, Scientists, & ReguFa my Specialists
DILLSBORO HYDROELECTRIC PROJECT (FERC No. 2602)
NOVEMBER 2008 WATER QUALITY REPORT
TABLE OF CONTENTS
Section Title Paize No.
SECTION I INTRODUCTION ......................................................................................... I
SECTION 2 WATER QUALITY SAMPLING LOCATIONS .................................................3
SECTION 3 MONTHLY WATER QUALITY SAMPLING DATA .........................................4
APPENDICES
APPENDIX A - MAP OF WATER QUALITY MONITORING LOCATIONS
APPENDIX B - PHOTOS
APPENDIX C - FLOWS
DILLSBORO HYDROELECTRIC PROJECT (FERC No. 2602)
NOVEMBER 2008 WATER QUALITY REPORT
LIST OF TABLES
Table Title Paize No.
TABLE 1 APPROXIMATE FLOWS ON NOVEMBER 20, 2008 (CFS) ...............................5
TABLE 2 WATER QUALITY DATA COLLECTED ON NOVEMBER 20, 2008 ...............5
11
Section 1
Introduction
This report details and summarizes the monthly water quality results at the Dillsboro
Hydroelectric Project (FERC No. 2602) (the Project) for the month of November 2008. The
Project is located in southwestern North Carolina on the Tuckasegee River in Jackson County,
and includes a dam, reservoir, and powerhouse. The Dillsboro Dam and Powerhouse are located
at approximately River Mile (RM) 31.6. During the preparation of the Project relicensing
application, a considerable amount of information was obtained on environmental resources
within the Project area. Since that time, a License Surrender Application was submitted to the
FERC, and Duke Energy Carolinas, LLC (Duke Energy) is taking initiatives to mitigate for the
various impacts of decommissioning the Project. The environmental resource information
gathered for the relicensing application is currently being used by Duke Energy and Devine
Tarbell & Associates, Inc. (DTA) for the monitoring program in preparation for the removal of
Dillsboro Dam.
The Dillsboro Dam removal project includes a three-phase environmental monitoring effort. The
current, or Pre-Removal Phase, is being used to gather baseline information on the variability of
physical, chemical, and biological processes in the Tuckasegee River prior to dam removal. To
capture seasonal effects, this phase has been designed to occur the year prior to, and leading up
to, dam removal. Pre-Removal Phase Monitoring will include the relocation of downstream
mussel populations to areas above the Dillsboro Project with known mussel populations. Dam
Removal Monitoring will take place during the actual dam demolition and removal period, which
will include environmental parameter threshold triggers to maintain ambient conditions. Post-
Dam Removal Monitoring will assess specific physical, chemical, and biological changes in the
Project area to determine when the river system has returned to background ambient conditions.
The current Pre-Removal Phase spans from January to December of 2008 and this report details
the water quality portion of the overall environmental monitoring program for November 2008.
The purpose of the Pre-Removal Phase is to gain an understanding of baseline conditions, and
the associated seasonal variability of those conditions, in the Tuckasegee River through the year.
The water quality parameters of this study include temperature, dissolved oxygen (DO), specific
1
Section I
Introduction
conductance, pH, turbidity, and total suspended solids (TSS). These measurements are being
collected monthly to document these baseline conditions, and ultimately, for comparison with
water quality data collected during the removal and post-removal phases, and for comparison
with historical data.
2
Section 2
Water Quality Sampling Locations
The locations of the water quality sampling sites were selected based on agency consultation and
previous study locations. There are nine water quality sampling locations near Dillsboro Dam
(see Figure A-1 in Appendix A). Photos of each water quality sampling location are included in
Appendix B.
The water quality monitoring study includes sections of river both above and below Dillsboro
Dam and covers about 2.5 river miles on the Tuckasegee River.
¦ M-1L and M-1R are below Dillsboro Dam at river mile 31.1. M-1L is located on the left
bank ascending and M-1R is located on the right bank ascending. The right and left banks
at M-1 are monitored separately because of the change in water quality across the river
from the influence of Scott's Creek. Scott's Creek is just upstream of M-1 on the left
bank.
¦ M-2 is located in Scott's Creek approximately 0.1 mile upstream of the confluence with
the Tuckasegee River.
¦ M-3 is located just below Dillsboro Dam at river mile 31.5.
E M-4 is at river mile 31.7, just above the dam in Dillsboro Pond at river mile 31.7.
¦ M-5L and M-5R are located on the left and right banks ascending, respectively, in a riffle
just upstream of Dillsboro Pond at river mile 32.8 (M-5R was added after the January
sampling trip). The right and left banks at M-5 are monitored separately to study the
influence of the Tuckasegee Water and Sewer Authority (TWSA). TWSA's discharge
point is located just upstream of M-5 on the left bank.
¦ M-6 is located on Savannah Creek, just upstream of the confluence with the Tuckasegee
River.
¦ M-7 is located on the mainstem Tuckasegee River, just upstream of Savannah Creek at
river mile 33.6.
3
Section 3
Monthly Water Quality Sampling Data
Mainstem Tuckasegee River flows were recorded at two nearby USGS stream flow measuring
gauges on November 20, 2008, the day when water quality sampling took place. These stream
gauges are:
¦ USGS Gauge 03508050 Tuckasegee River at SR 1172 near Cullowhee, NC; and
¦ USGS Gauge 03510577 Tuckasegee River at Barker's Creek, NC.
Flow data from the USGS gauges is included in Table C-1 in Appendix C. In addition to flow
data collected at USGS gauges, DTA measured the flows at two main tributaries within the study
area: Savannah Creek and Scott's Creek. These tributary flows were measured at the same time
that water quality sampling took place (Table C-2 in Appendix C). The approximate flow at
each mainstem site during the time that the water quality data was collected was determined
based on a combination of flows measured at the USGS gauge near Cullowhee and the tributary
flows measured by DTA. Flows measured at the upstream Cullowhee gauge (RM 47.0) were
increased by 8% to account for the additional drainage area between the gauge and Savannah
Creek. The timing of the flow was then adjusted from the gauge location to each water quality
monitoring location based on a previous travel time study. The flow measured at Savannah
Creek was then added to monitoring locations between Savannah Creek and Scott's Creek. For
water quality monitoring locations below Scott's Creek, both Savannah Creek and Scott's Creek
measured flows were added to the adjusted mainstem flow. The resulting approximate flows for
each water quality monitoring location are provided below in Table 1.
At each of the water quality sampling sites, temperature, DO, specific conductance, pH,
turbidity, and TSS were measured. The water quality sampling parameters are summarized in
Table 2. The water quality instrument used in this study was a Hydrolab® MSS. The Hydrolab
was calibrated in a laboratory just before the November 2008 sampling trip, including a Winkler
Titration. DTA checked the calibration of the Hydrolab against known standards prior to, and
after, the November sampling trip.
4
Section 3 Monthly Water Quality Sampling Data
TABLE 1
APPROXIMATE FLOWS ON NOVEMBER 20, 2008 (CFS)
Location Description Flow
M-1 L Left ascending bank below Scott's Creek (RM 31.1) 90
M-1R Right ascending bank below Scott's Creek (RM 31.1) 90
M-2 Scott's Creek 27
M-3 Below Dillsboro Dam (RM 31.5) 60
M-4 Above Dillsboro Dam (RM 31.7) 60
M-5L Left ascending bank above Dillsboro Pond (RM 32.8) 60
M-5R Right ascending bank above Dillsboro Pond (RM 32.8) 60
M-6 Savannah Creek 20
M-7 Above Savannah Creek (RM 33.6) 40
TABLE 2
WATER QUALITY DATA COLLECTED ON NOVEMBER 20, 2008
Location Description Temp DO Cond pH Turb TSS
(degrees C) (mg/L) Si (units) (NTU) (mg/L)
Left ascending bank below
M-11,
Scott's Creek RM 31.1 5.7 12.40 32 6.73 2.0 < 2.0
Right ascending bank below
M-1R
Scott's Creek RM 1) 5.3 12.52
1 31 6.57 1.7 < 2.0
M-2 Scott's Creek 5.4 12.41 49 6.90 1.7 < 2.0
M-3 Below Dillsboro Dam 5.4 12.14 27 6
57 2
3 < 2
0
RM 31.5 . . .
M-4 Above Dillsboro Dam 6.0 11.62 29 6
67 2
3 2
8
RM 31.7 . . .
M-51, Left ascending bank above 8.1 11.49 50 6
87 2
4 2
2
Dillsboro Pond RM 32.8 . . .
M-5R Right ascending bank above 6.4 11.87 27 6
52 1
7 < 2
0
Dillsboro Pond RM 32.8 . . .
M-6 Savannah Creek 5.7 12.17 35 6.82 2.3 < 2.0
M-7 Above Savannah Creek 7.0 11
53 23 7
26 1
6 < 2
0
RM 33.6 . . . .
.-F-- -p"' wow ati-y- vy UIc vunc nueigy t\na1yuQd1 LU00['dWry at tne mcuture Nuclear Gompiex in
Huntersville, North Carolina. This laboratory is certified by the North Carolina Division of Water Quality.
The water quality sampling trip took place on November 20, 2008. Prior to the sampling trip,
there were three consecutive days without precipitation according to the USGS precipitation
gauge at Bryson City, which records daily rainfall. The water quality data collected during the
November sampling trip was collected under slightly higher flow conditions compared to the
October sampling trip. November's sampling trip took place during one of the lowest flow
conditions of the entire Pre-Removal Phase water quality monitoring. According to standards set
by the North Carolina Division of Water Quality, the upper end of the study reach (Savannah
5
Section 3 Monthly Water Quality Sampling Data
Creek to Dillsboro Dam) is classified as Class C freshwaters/trout, and the study reach below
Dillsboro Dam is classified as Class C freshwaters. All of the water quality parameters collected
during November 2008 were within the set limits for Class C freshwaters/trout above the dam
and Class C freshwaters below the dam.
All DO values were above water quality limits for Class C freshwaters/trout above the dam
(6 mg/L daily average; 5 mg/L daily minimum) and for Class C freshwaters below the dam
(5 mg/L daily average; 4 mg/L daily minimum). The specific conductance values measured in
Scott's Creek and at M-5L were noticeably higher than the values measured at the other water
quality sampling locations. Scott's Creek has typically had the highest specific conductance
values of all of the monitoring locations each month during this study. M-5L is located on the
mainstem just downstream of the Tuckasegee Water and Sewer Authority which likely
contributed to the high specific conductance measurement. Turbidity values at sampling
locations below Dillsboro Dam were all within the state standard of 50 NTUs and sampling
locations above Dillsboro Dam were all within the state standard of 10 NTUs. In fact, all
turbidity values collected during sampling were less than 3 NTUs. Water temperatures in the
Tuckasegee and Savannah and Scott's Creek have all dropped a couple of degrees due to the
change in seasons.
As part of the Pre-Removal Phase Monitoring study, DTA plans to continue to collect water
quality data in a variety of flows. This will demonstrate how the water quality in the Tuckasegee
River changes during normal seasonal storm events.
6
APPENDICES
APPENDIX A
MAP OF WATER QUALITY MONITORING LOCATIONS
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APPENDIX B
PHOTOS

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Photo B-1: M-1L, Left Ascending Bank below Scott's Creek (RM 31.1)
Photo B-2: M-2, Scott's Creek
Photo B-3: M-3, Below Dillsboro Dam (RM 31.5)
Photo B-4: M-4, Above Dillsboro Dam (RM 31.7)

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Photo B-6: M-5R, Right Ascending Bank above Dillsboro Pond (RM 32.8)
Photo B-5: M-5L, Left Ascending Bank above Dillsboro Pond (RM 32.8)
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Photo B-7: M-6, Savannah Creek

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Photo B-8: M-7, Above Savannah Creek (RM 33.6)
APPENDIX C
FLOWS
The table below provides recorded flows at these USGS stream gauges. The date of the
sampling trip is included, as well as the weather conditions.
TABLE C-1
FLOWS ON NOVEMBER 20, 2008
Weather Conditions: Sunny, 46 degrees
Cullowhee Barker's Creek
Time Stage
ft Discharge
cfs Stage
ft Discharge
cfs
11:00 3.78 32 3.07 191
11:15 3.78 32 3.05 186
11:30 3.77 31 3.05 186
11:45 3.76 30 3.04 183
12:00 3.82 37 3.03 181
12:15 5.06 333 3.03 181
12:30 5.33 432 3.02 178
12:45 5.40 460 3.02 178
13:00 5.41 464 101 176
13:15 5.42 468 3.00 173
13:30 5.41 464 3.00 173
13:45 5.48 492 2.99 171
14:00 5.68 575 2.99 171
14:15 5.84 645 2.98 168
14:30 5.89 668 2.98 168
14:45 5.92 682 2.97 166
15:00 5.94 691 2.97 166
15:15 5.95 696 2.96 164
15:30 5.95 696 2.96 164
15:45 5.89 668 2.95 161
16:00 5.75 605 2.95 161
In addition, tributary flows near Dillsboro Dam were measured as part of the water quality
monitoring at Savannah Creek and Scott's Creek. Flows were measured manually using a hand
held Swoffer velocity meter and topset wading rod.
TABLE C-2
TRIBUTARY FLOW MEASUREMENTS
Tributary Date and Time Flow (cfs)
Savannah Creek 11/20/08 15:00 20
Scott's Creek 11/20/08 15:50 27
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