20030179 Ver 6_Monitoring Report_20090130

WEnergy®
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
January 28, 2009
Mr. John Dorney
NC Division of Water Quality
1617 Mail Service Center
Raleigh, NC 27699-1617
Subject: Dillsboro Hydroelectric Project's December Water Quality Monitoring Report
Mr. Dorney:
Enclosed is the December 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. This concludes our one year of pre-dam removal water
quality monitoring. Following dam removal (presently scheduled for January 2010), we will
implement our post-dam water quality monitoring. If you have questions regarding this report,
please do not hesitate to give me a call at 704/382-0805.
Sincerely,
b. l 4t4 &Wy?k
D. Hugh Barwick
Senior Environmental Resource Manager
Enclosure: Report
U9@20YR,
JA N 3 0 2009
QUALITY AND STOR MWATER BRANCH
DILLSBORO HYDROELECTRIC PROJECT
(FERC No. 2602)
DECEMBER 2008 WATER QUALITY REPORT
Charlotte, North Carolina
Prepared by:
HDRIDTA
Charlotte, North Carolina
JANUARY 2009
tuuh6l
DTA
Prepared for:
DUKE ENERGY CAROLINAS, LLC
DILLSBORO HYDROELECTRIC PROJECT (FERC No. 2602)
DECEMBER 2008 WATER QUALITY REPORT
TABLE OF CONTENTS
Section Title Page 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)
DECEMBER 2008 WATER QUALITY REPORT
LIST OF TABLES
Table Title Page No
TABLE I APPROXIMATE FLOWS ON DECEMBER 28, 2008 (CFS) ...............................5
TABLE 2 WATER QUALITY DATA COLLECTED ON DECEMBER 28, 2008 ................5
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 December 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 HDRIDTA
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 December 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
conductance, pH, turbidity, and total suspended solids (TSS). These measurements are being
Section 1
Introduction
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-11, is located on the left
bank ascending and M-1 R is located on the right bank ascending. The right and left banks
at M-l 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.
¦ 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 December 28, 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, HDRIDTA 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 Q. 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 HDRIDTA. 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. HDRIDTA checked the calibration of the Hydrolab against known standards prior to,
and after, the December sampling trip.
4
Section 3 Monthly Water Quality Sampling Data
TABLE 1
APPROXIMATE FLOWS ON DECEMBER 28.2008 (CFS)
Location Description Flow
M-11- Left ascending bank below Scott's Creek (RM 31.1) 360
M-1R Right ascending bank below Scott's Creek (RM 31.1) 360
M-2 Scott's Creek 226
M-3 Below Dillsboro Dam (RM 31.5) 130
M-4 Above Dillsboro Dam (RM 31.7) 130
M-5L Left ascending bank above Dillsboro Pond (RM 32.8) 130
M-5R Right ascending bank above Dillsboro Pond (RM 32.8) 1.30
M-6 Savannah Creek 68
M-7 Above Savannah Creek (PM 33.6) 60
TABLE 2
WATER QUALITY DATA COLLECTED ON DECEMBER 28.2008
Location Description Temp DO Cond pH Turb TSS
(degrees C) (mg/L) ( Sj (units) (NTU) (mg/L)
M-11 Left ascending bank below
,
Scott's Creek (RM 3 L 1) 10.8 10.51 27 6.08 5.6 5.4
M-1R Right ascending bank below

Scott's Creek (PM 1) 10.5 10.60 22
1 6.48 6.4 5.6
M-2 Scott's Creek 11.2 10.50 30 6.80 31.6 42
M-3 Below Dillsboro Dam
RM 3 1.5) 10.3 10.76 ZO 6.56 3.9 3.4
M-4 Above Dillsboro Dam

RM 31.7) 10.4 10.36 20 6.60 4.4 5.0
M-51 Left ascending bank above
,
Dillsboro Pond RM 32.8) 10.3 10.56 24 6.68 2.5 2.2
M-5R Right ascending bank above

Dillsboro Pond RM 32.8) 10.7 10.57 26 6.75 7.8 6.2
M-6 Savannah Creek 11.0 10.49 31 6.73 17.7 24
M 7 Above Savannah Creek

RM 33.6) 10.2 10.61 18 6.71 2.3 < 2.0
-- - -- -.... , , -sy --y-at uawiawiy UL use iwcuwre LNuciear t ompiex in
HuntersvilIe, North Carolina. This laboratory is certified by the North Carolina Division of Water Quality.
The water quality sampling trip took place on December 28, 2008. Prior to the sampling trip,
there were four consecutive days with precipitation (totaling 0.97 inch) according to the USGS
precipitation gauge at Bryson City, which records daily rainfall. HDRIDTA reported steady rain
during the sampling trip and the USGS precipitation gauge recorded 0.86 inch of rain on
December 28, 2008. The water quality data collected during the December sampling trip was
collected under substantially higher flow conditions compared to the September, October, and
November sampling trips due to the rain event. According to standards set by the North Carolina
5
Section 3 Monthly Water Quality Sampling Data
Division of Water Quality, the upper end of the study reach (Savannah Creek to Dillsboro Dam)
is classified as Class C freshwaters/trout, and the study reach below Dillsboro Dam is classified
as Class C freshwaters. Most of the water quality parameters collected during December 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 and pH values at each
sampling location were all relatively close in proximity. Turbidity values at sampling locations
on the Tuckasegee River below Dillsboro Dam were all within the state standard of 50 NTUs.
Turbidity data collected at sampling locations on the Tuckasegee River above Dillsboro Dam
were all within the state standard of 10 NTUs. The two tributaries, Savannah and Scott's Creek,
both had elevated turbidity values of nearly 18 and 32 NTUs, respectively, likely due to the
runoff event at the time of sampling. Both of these tributaries are classified as Class C
freshwaters/trout with a state standard of 10 NTUs. Similarly, Savannah and Scott's Creek also
had elevated TSS levels. A combination of higher air temperatures and increased surface runoff
due to the rain event caused water temperatures at all of the sampling locations to be nearly twice
that of water temperatures recorded in November 2008.
As part of the Pre-Removal Phase Monitoring study, HDRIDTA 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
a ? =
o r
.---
ie C4
?' • ? ?:' art ?
A . a>; H
? , r a r?a.f ? aqi,

r
03
4{
?
L

L
? ? +w
1 ,
77

C-A

? iS
}4 v
y
f
t ?.
`
"
til ? e.
tl,
#?. ?i+ rte' r ?: `,
? '?
?
` , ? y
'
'
?
?
,- 1a
?a ii
?1
•
Y
.?
` -•• ! _
?
+? ?e ??? ??•'' y I4T
? ? ?`- ?r
ly ??\? . .?'•"?..?-.-
' ??7Lrr., 'fi`r'-?4
t ? , f
4,

' '
' ?
•
/J/ `- ?
?j • I., ? t } .. }? r ?J
'?"• •..>?1'?tei.? ? ;..r, ?
r ? t.?.-. Y
?;? .. -
R '
41 b.

? •
:? t ? ?
g?+ \ { ti
car , S .

APPENDIX B
PHOTOS
Photo B-1: M-111, Right Ascending Bank below Scott's Creek (RM 31.1)
Photo B-2: M-2, Scott's Creek

4 i-?t Y
* r
y Y
Photo B-4: M-4, Above Dillsboro Dam (RM 31.7)
Photo B-3: M-3, Below Dillsboro Dam (RM 31.5)

4
1 Y'
Photo B-5: M-5L, Left Ascending Bank above Dillsboro Pond (RM 32.8)
r
_ t
Photo B-6: M-5R, Right Ascending Bank above Dillsboro Pond (RM 32.8)

C' .,.???A"t f. .fl ?:'a ,. 1' ?tt, , +a ?•? ? .y.e •Y 1' III
Photo B-7: M-6, Savannah Creek
?? ?? t?,.y.F C• y / ' i

l

X11 _ '+!• i?.xd.'?YPi.Y '?r`i' Y
1
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-I
FLOWS ON DECEMBER 28, 2008
Weather Conditions: Steady rain, 60 degrees
Cullowhee Barker's Creek
Time Stage
(ft) Discharge
cfs Stage
ft Discharge
cfs
7:00 3.92 51 3.65 388
7:15 3.91 49 3.65 388
7:30 3.92 51 3.64 384
7:45 3.95 55 3.65 388
8:00 3.91 49 3.64 384
8:15 3.93 52 3.65 388
8:30 3.92 51 3.64 384
8:45 3.92 51 3.64 384
9:00 4.03 68 3.64 384
9:15 4.60 193 3.63 380
9:30 4.84 261 3.64 384
9:45 4.92 286 3.64 384
10:00 4.94 293 3.66 393
10:15 4.93 290 3.67 397
10:30 4.96 299 3.69 406
10:45 5.35 440 3.70 410
11:00 5.82 636 3.72 419
11:15 5.98 710 3.74 428
11:30 6.05 743 3.76 437
11:45 6.06 748 3.78 447
12:00 6.07 753 3.80 456
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 12/28/08 10:00 68
Scott's Creek 12/28/08 11:15 226

.-r
U
NW
W
r?
_V
?7r
n
y
c3
"J
J
3
v
R
73
bA
c
a.
c
n
L
L
n
:C
G
O
u
n
n
O
U
a?
bU
R
bq
y
y
3
0
x
0
N
N
x
0
N
x
O
n
N
\J
x
O
r
N
T
x
0
rq
N
x
x
0
a
c\
o y
? R
N 0
10
00
O
O
M
x
0
0
M
x
0
M
M
00
M
x
O
M
x
0
o
o ? o ° o 0 0 °o ? °o
(SjJ) MOjA

N
1
U
W
1?1
C.)
z
19
v
U
L
s
L
ar
CQ
L
6J
z
U
U
bQ
a?
..1
V
F
0
rl
M
M
O
CIO
/CS
V
h

n
J
CS
3

T
L

:J
n
L
V
1
^J
L
n
v
L
x
0
3
N
N
x
O
nl
x
C7
N
O
O
N
a
x
0
N
b
x
0
a
N
n
o
c
1.0
O
O
M
x
O
0
M
Q
x
O
M
M
x
M
x
O
M
x
O
O
O O O O
[V N ^ O O
O ?n
(SJ3) M0(64