20070812 Ver 1_19 - Wetland and Riparian Habitat Final Report (2)_20080502

Yadkin Project
FERC No. 2197 NC
WETLAND AND RIPARIAN
HABITAT ASSESSMENT
Final Study Report
JUNE 2005
Yadkin Project
FERC No. 2197 NC
WETLAND AND RIPARIAN
HABITAT ASSESSMENT
Final Study Report
Prepared for
ALCOA POWER GENERATING INC.
Yadkin Division
293 NC 740 Highway
Badin, NC 28009-0576
Prepared by
NORMANDEAU ASSOCIATES, INC.
25 Nashua Road
Bedford, NH 03110
R-19556.002
June 2005
Wetland and Riparian Habitat Assessment
Table of Contents
Page
SUMMARY ............................................................................................................................ vii
1.0 INTRODUCTION ........................................................................................................ ..1
2.0 BACKGROUND .......................................................................................................... ..1
3.0 STUDY AREA ............................................................................................................. ..3
4.0 STUDY PURPOSE AND OBJECTIVES ...................................................................... .. 3
5.0 STUDY METHODS ..................................................................................................... .. 3
5.1 HYDROLOGIC REGIME ........................................................................................... .. 3
5.2 MAP OF WETLANDS AND RIPARIAN HABITATS ........................................................ .. 4
5.2.1 Photointerpretation ..................................................................................... ..4
5.2.2 Image Transfer and Mapping ...................................................................... .. 6
5.2.3 Office Quality Control Methods .................................................................. .. 6
5.3 FIELD SURVEY ...................................................................................................... .. 7
5.4 ANALYSIS OF PROJECT OPERATION ........................................................................ .. 8
5.5 EFFECT OF ALTERED PROJECT OPERATION ............................................................. .. 9
6.0 LANDSCAPE SETTING .............................................................................................11
6.1 VEGETATION .................................................................. .......................................11
6.2 SUBSTRATES ................................................................... .......................................11
6.3 HYDROLOGIC REGIME ..................................................... .......................................14
6.3.1 Long-term Water Levels ....................................... .......................................14
6.3.2. 2004 Water Levels ............................................... .......................................14
7.0 SUMMARY OF EXISTING STUDIES AND INFORMATION ON THE
PROJECT AREA .........................................................................................................21
8.0 EXISTING CONDITIONS ..........................................................................................22
8.1 VEGETATION CHARACTERIZATION ............................................... ...........................22
8.1.1 Palustrine Forested Wetlands ............................................ ...........................22
8.1.2 Palustrine Forested Floodplain Wetlands ........................... ...........................29
8.1.3 Scrub-Shrub Wetland ....................................................... ...........................32
8.1.4 Sparse Scrub-Shrub Wetland ............................................ ...........................32
8.1.5 Emergent Wetland ........................................................... ...........................33
8.1.6 Aquatic Bed .................................................................... ...........................34
8.1.7 Upland ............................................................................ ........................... 34
8.2 WATER WILLOW ON NARROWS .................................................... ........................... 36
8.3 MAJOR WETLAND FUNCTIONS ..................................................... ...........................41
8.3.1 Flood Control .................................................................. ...........................43
8.3.2 Sediment Trapping ........................................................... ...........................43
8.3.3 Nutrient Removal ............................................................ ...........................43
8.3.4 Fish Habitat ..................................................................... ...........................44
8.3.5 Wildlife Habitat ............................................................... ...........................44
8.3.6 Social Values ................................................................... ...........................45
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Wetland and Riparian Habitat Assessment
9.0 EFFECTS OF CURRENT PROJECT OPERATION ..................................................45
9.1 HYDROLOGY ..........................................................................................................45
9.2 WATER WILLOW IN NARROWS ................................................................................45
9.3 DEVELOPMENT ......................................................................................................48
10.0 EFFECTS OF ALTERED PROJECT OPERATION ................................................... 47
10.1 HIGH ROCK ALTERNATIVE 1 - NEAR-FULL YEAR ROUND .........................................50
10.2 HIGH ROCK ALTERNATIVE 2 - EXTENDED NEAR-FULL SEASON ................................ 53
10.3 HIGH ROCK ALTERNATIVE 3 - ADDITIONAL USE OF STORAGE ..................................54
10.4 TUCKERTOWN ALTERNATIVE - INCREASED SHORT TERM FLUCTUATIONS .................. 55
10.5 NARROWS ALTERNATIVE - ADDITIONAL USE OF STORAGE ........................................ 55
10.6 FALLS ALTERNATIVE ..............................................................................................55
11.0 CONCLUSIONS AND RECOMMENDATIONS .........................................................55
12.0 REFERENCES CITED ................................................................................................53
APPENDIX A: PLANT SPECIES OBSERVED IN COVER TYPES THROUGHOUT THE
YADKIN PROJECT AREA
APPENDIX B: INCIDENTAL OBSERVATIONS OF WILDLIFE SPECIES OBSERVED
THROUGHOUT THE YADKIN PROJECT AREA
APPENDIX C: COMMENT RESPONSE TAB LE
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Wetland and Riparian Habitat Assessment
List of Figures
Page
Figure 1-1. Locus of Yadkin Project ............................................................................................2
Figure 5.4-1. Data collection form for water willow study .............................................................. 10
Figure 5.5-1. High Rock water level scenarios provided by APGL ................................................. 12
Figure 6.3-1. Minimum, mean and maximum daily water level elevations (USGS datum) in
High Rock Reservoir for the period of January 1, 1986 to December 31, 2003 ............. 16
Figure 6.3-2. Minimum, mean and maximum daily water level elevations (USGS datum) in
Tuckertown Reservoir for the period of January 1, 1986 to December 31, 2003............ 16
Figure 6.3-3. Minimum, mean and maximum daily water level elevations (USGS datum) in
Narrows Reservoir for the period of January 1, 1986 to December 31, 2003 ................. 17
Figure 6.3-4. Minimum, mean and maximum daily water level elevations (USGS datum) in
the Falls Reservoir for the period of January 1, 1986 to December 31, 2003 ................. 17
Figure 6.3-5. Comparison of 2004 water level elevations (USGS datum) with long-term mean,
and 2002 drought at High Rock Reservoir ................................................................. 19
Figure 6.3-6. Comparison of 2004 water level elevations (USGS datum) with long-term mean,
and 2002 drought at Tuckertown Reservoir ............................................................... 19
Figure 6.3-7. Comparison of 2004 water level elevations (USGS datum) with long-term mean,
and 2002 drought at Narrows Reservoir .................................................................... 20
Figure 6.3-8. Comparison of 2004 water level elevations (USGS datum) with long-term mean,
and 2002 drought at Falls Reservoir ......................................................................... 20
Figure 8.1-1. Cover types within the 200-foot Project Area on Upper High Rock Reservoir .............. 23
Figure 8.1-2. Cover types within the 200-foot Project Area on the Central Section of High
Rock Reservoir ...................................................................................................... 24
Figure 8.1-3. Cover types within 200-foot Project Area on Lower High Rock Reservoir ................... 25
Figure 8.1-4. Cover types within 200-foot Project Area on Tuckertown Reservoir ............................ 26
Figure 8.1-5. Cover types within 200-foot Project Area on Narrows and Falls Reservoirs ................. 27
Figure 8.2-1. Narrows Pier and Water Willow Study Area ............................................................. 38
Figure 8.2-2a. Example of a lot with an intact water willow bed on left side of dock and
clearing on right side .............................................................................................. 42
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Wetland and Riparian Habitat Assessment
Figure 8.2-2b. Example of clearing and sand imported within a water willow bed .............................. 42
Figure 8.2-3. Example of trampling impacts in water willow bed .................................................... 42
Figure 10-1. High Rock contour intervals from 624N - 618N and cover types, divided into
hydrogeomorphic sections used in alternatives assessment ......................................... 50
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Wetland and Riparian Habitat Assessment
List of Tables
Page
Table 6.2-1. Summary of hydric soils that may occur within the Project Area .......................... ....... 13
Table 6.3-1. Summary of water elevations (feet USGS) statistics in the Yadkin reservoirs
based on daily data (1986-2003)' and hourly data (1997-2003)b ........................... ....... 15
Table 6.3-2. Comparison of water elevation analyses for Falls Reservoir using daily and
hourly data for the period of 1997-2003 ............................................................. ....... 18
Table 8.1-1. Summary of acreages for cover types within 200 feet of Yadkin reservoirs ........... ....... 28
Table 8.1-2. List of dominant plant species by habitat on Yadkin Project Area ......................... ....... 30
Table 8.2-1. List of plant species observed in shallow marshes on Narrows Reservoir .............. ....... 37
Table 8.2-2. Characteristics of water willow, piers and shorelines of new and old piers ............ ....... 39
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Wetland and Riparian Habitat Assessment
SUMMARY
The Wetlands and Riparian Habitat Assessment Final Study Report presents the results of a survey of
wetland habitats at the Yadkin Project. The study was conducted by Normandeau Associates, Inc.
(NAI) as part of the Federal Energy Regulatory Commission (FERC) relicensing process for the
Yadkin Project. The study was conducted in accordance with the Final Study Plan that was
developed by Alcoa Power Generating, Inc. (APGI) in consultation with the Wetlands, Wildlife and
Botanical Issue Advisory Group (IAG). Specific objectives identified in the Final Study Plan
included:
¦ Identify and map vegetated wetlands and riparian habitats within the influence of reservoir water
levels, including aquatic beds, emergent and shrub-wetlands and some forested wetlands.
¦ Evaluate effects of current Project operations, including reservoir water level fluctuations, on these
wetlands and riparian habitats.
¦ Evaluate how significant changes in Project operations, including both increasing and decreasing
short-term and long-term reservoir drawdowns would impact existing wetlands, or would allow for
additional wetland development.
¦ Qualitatively assess the effects of reservoir facilities (such as piers, boat ramps, beaches, bulkheads
and other forms or shoreline hardening) on wetlands and riparian habitats, with a particular
emphasis on the potential impact of piers on water willow (Justicia americana) at Narrows
Reservoir.
In accordance with the study plan, Normandeau mapped all of the wetlands located within the study
area which included all of the Project reservoirs as well as the shoreline within 200 feet of the
reservoirs. Wetland delineation and mapping was done using aerial photography and field surveys.
Wetlands were categorized into six categories: forested wetland; forested floodplain wetland; scrub-
shrub wetland; sparse scrub-shrub wetland; emergent marsh; and aquatic bed. The remainder of the
study area was categorized into seven upland cover types
Of the four Yadkin Proj ect reservoirs, High Rock supports the greatest total acreage of wetland
habitat with a total of 3268 acres. The vast majority of the wetland acres found at High Rock are
concentrated in the upper end of the reservoir, where extensive areas of forested floodplain wetlands
exist and where sizeable scrub-shrub wetlands have developed on deltas and islands formed by
sediment deposits. Elsewhere in the reservoir, wetlands are noticeably absent, and there are almost
no stands of emergent marsh or aquatic bed wetlands.
The concentration of wetlands in the upper end of High Rock reservoir is primarily the result of
colonization by wetland vegetation on large areas of sediment deposition which has created a
complex of islands, deltas and sand bars. These wetlands provide the most abundant riparian habitat
on High Rock reservoir and are important to the reservoir as fish spawning and rearing habitat. These
delta wetlands appear to be relatively unaffected by fluctuating reservoir water levels, but are clearly
affected by high river flows which cause flooding in the floodplain and can generate flow velocities
that dislodge vegetation and remobilize the deposited sediments.
The paucity of wetlands in the lower portion of the reservoir is due to the current operation of the
reservoir which is characterized by a period of reservoir drawdown of between 10-15 feet during the
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Wetland and Riparian Habitat Assessment
fall and winter. In addition, drawdowns of 5 feet or more late in the summer growing season also
adversely impact wetland formation. Few native emergent or aquatic species can tolerate the
combined effects of the conditions created in the reservoir drawdown zone: flooding for periods in
the spring, followed by drying as the water levels drop in the late summer and fall. Exposure to
freezing and desiccation in the winter further stresses any overwintering plant material. Annuals are
the best strategists for taking advantage of regeneration opportunities, as was observed during the
drought of 2002 when entire sections of the reservoir that were exposed by the prolonged drawdown
were colonized in the late summer by a grass or sedge.
Tuckertown Reservoir supports 253.8 acres of wetlands. The wetlands at Tuckertown are a mix of all
six wetland types. Within each of the wetland types found at Tuckertown, the species composition of
the wetlands is very diverse. In particular, the emergent marsh and aquatic bed wetlands contain a
diverse mix of species and exhibit a classic pattern of zonation that is a characteristic of a healthy
wetland system. The extensive development of emergent marsh and aquatic bed wetlands at
Tuckertown is attributed to its relatively stable water levels, quiet water, and fine, gently sloping
substrates.
Narrows Reservoir supports 333.1 acres of wetlands. The most prevalent wetland type at Narrows is
emergent marsh which accounts for 178 acres of the total. In contrast to Tuckertown, emergent
marsh wetlands on Narrows are not species diverse but are instead dominated by water willow. In
some cases beds of emergent vegetation were found to be made up entirely of water willow. The
existence of large stands of water willow on Narrows suggests that growing conditions are very
suitable for this species which is particularly tolerant of alternating periods of inundation and
exposure.
Falls Reservoir supports only 3.2 acres of wetlands. This reservoir is characterized by steep, rocky
slopes and substrates and a riverine nature. These natural features along with very frequent
fluctuations in reservoir water levels serve to limit additional wetland development on Falls
Reservoir. The Falls Tailrace, which extends approximately 1 mile into Tillery Reservoir, was
estimated to have 8.1 acres of wetlands.
Summary of Wetland Acres at the Yadkin Project Reservoirs

Wetland Type High
Rock
Tuckertown
Narrows
Falls Falls
Tailrace Project
Total
Forested Wetland 234.2 64.3 51.2 0.3 5.8 355.8
Forested Floodplain
Wetland 2194.1 87.0 39.8 0 0.3 2321.2
Scrub-Shrub Wetlands 324.6 40.4 3.9 0.3 0.3 369.5
Sparse Scrub-Shrub
Wetlands 484.4 4.4 0 0 0 488.8
Emergent Marsh 28.1 44.7 178.2 2.6 1.7 250.1
Aquatic Bed 2.9 14.3 60.0 0 0 77.2
Reservoir Total 3268.3 253.8 333.1 3.2 8.1 38665
A second objective of the Wetlands and Riparian Habitat Assessment was to evaluate qualitatively
the potential impact to reservoir wetlands that would occur under alternative water level regimes. To
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Wetland and Riparian Habitat Assessment
address this issue, NAI examined three different water level scenarios for High Rock Reservoir, and
one each at Tuckertown and Narrows reservoirs.
The High Rock alternatives evaluated included: Alternative 1) maintaining the reservoir "near-full"
(within 3 feet of full) year round, Alternative 2) extending the season during which the reservoir was
maintained "near-full" and reducing the total magnitude of the winter drawdown, and Alternative 3)
increasing the winter drawdown and maintaining summer water levels within 5 feet of full in order to
use additional storage. The results of this analysis can be summarized as follows:
¦ Alternative 1 - "Near-Full Year Round" - a stable water level would result in the development of
emergent wetlands and aquatic beds along much of the shoreline of High Rock, probably similar
in zonation and species diversity to Tuckertown. A stable water level is also likely to have the
adverse impact of eliminating much of the black willow (Salix nigra) that has colonized the delta
area, particularly in the deeper areas. Emergents could colonize some of the areas, but the area
would be more vulnerable to riverine high flow events.
¦ Alternative 2- "Extended Near-Full Season" - a shorter winter drawdown would likely enhance
wetland development around the perimeter of High Rock, probably similar to Narrows with water
willow dominating the emergent wetlands. The black willow beds in the delta area would decline
similar to Alternative 1.
¦ Alternative 3 - "Additional Use of Storage" - would be most detrimental to existing wetlands
around High Rock. While the black willow stands on the delta area would probably thrive and
expand, the in-pond wetlands around the periphery of the reservoir would be less stable. The
combination of a longer winter drawdown, a lower average water level, and periodic full pond
levels would create a difficult environment for emergent wetlands to persist or colonize.
At Tuckertown, increases in short-term water level fluctuations by several feet could reduce the
species diversity and alter the zonation of the emergent wetlands now prevalent on the reservoir.
Water willow would be likely to expand, because of its tolerance of water level fluctuations. Aquatic
beds could also decline if the fluctuations were prolonged enough for them to dehydrate. Combined,
these two effects would degrade the wetlands to the more monotypic vegetation found on Narrows.
At Narrows, any change in project operation that would result in a greater winter drawdown and/or
more routine and deeper draws in the summer would likely have an adverse impact on the water
willow beds. While water willow is clearly tolerant of the current summer water level fluctuations,
the combination of a winter drawdown and greater summer fluctuations could exceed this species'
tolerance and result in a decline.
Finally, the wetlands study examined the impacts of piers on water willow at Narrows Reservoir.
Results of this part of the investigation showed that water willow is generally capable of growing
close to and around piers, even piers that are situated low to the water. However, associated uses of
the pier for boating, jet skis, swimming and other activities clearly can disturb and destroy these beds.
Other human disturbance activities along the shoreline such as the addition of sand and the intentional
removal of aquatic plants were also observed to have a detrimental effect on water willow located
along developed portions of Narrows Reservoir.
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Wetland and Riparian Habitat Assessment
1.0 INTRODUCTION
Alcoa Power Generating Inc (APGI) is applying to the Federal Energy Regulatory Commission
(FERC) for anew license for the Yadkin Hydroelectric Project. The Project consists of four
reservoirs, dams, and powerhouses (High Rock, Tuckertown, Narrows, and Falls) located on a 38-
mile stretch of the Yadkin River in central North Carolina (Figure 1-1). The Project generates
electricity to support the power needs of Alcoa's Badin Works and its other aluminum operations, or
is sold on the open market.
In this study, wetland and riparian habitats were mapped, inventoried, and characterized throughout
the study area. The effects of existing Project operations, including reservoir operations and tailwater
flows, were assessed, and potential changes to these habitats due to altered Project operations were
considered. In addition, at Narrows Reservoir, the impacts of piers on water willow (Justicia
americana) were assessed. Water willow is the dominant emergent aquatic vegetation throughout the
Yadkin Project, and is important for shoreline stabilization and fish habitat. The North Carolina
Wildlife Resources Commission (NCWRC) expressed particular concern for the impact of piers on
this species in Narrows Reservoir, which is the only one of the four reservoirs to have both an
abundance of water willow and piers.
2.0 BACKGROUND
As part of the relicensing process, APGI prepared and distributed, in September 2002, an Initial
Consultation Document (ICD), which provides a general overview of the Project. Agencies,
municipalities, non-governmental organizations and members of the public were given an opportunity
to review the ICD and identify information and studies that were needed to address relicensing issues.
To further assist in the identification of issues and study needs, APGI formed Issue Advisory Groups
(IAG) to advise APGI on resource issues throughout the relicensing process. Through meetings,
reviews and comments, the IAGs assisted in developing the Study Plans for the various resource
issues, and will further review and comment on the findings resulting from the implementation of the
study plans. The Wetlands, Wildlife and Botanical IAG was interested in the evaluation of wetlands
and riparian habitats under existing conditions, assessing how these habitats could be affected by
existing Project operations, and any changes that may occur as a result of altered Project operations, if
proposed. A draft study report was provided to the WWB IAG for review and comments. Comments
on the draft study report and how they were addressed in the final report are summarized in Appendix
C. This Final Study Report presents the findings of the Wetlands and Riparian Habitat Assessment
studies, following implementation of the Final Study Plan, dated June 2003.
In addition to a general assessment of Project wetlands, the NCWRC is also concerned with the
impact of piers on emergent wetlands and aquatic beds, particularly at Narrows Reservoir, which are
typically dominated by the species water willow. The NCWRC requested that this issue be a
secondary focus of this study, and Narrows Reservoir was selected as the appropriate study area.
Narrows Reservoir has an abundance of both water willow and piers, whereas the other three
reservoirs may have an abundance of one but not both. In a study conducted for APGI by NC State
University (Touchette et al. 2001), data on water willow growing under and adjacent to piers were
collected for one growing season. The purpose of this portion of the study is to conduct a follow-up
investigation, building on the information previously collected, to assess the relationship between
piers and water willow.
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Wetland and Riparian Habitat Assessment
Figure 1-1. Locus of Yadkin Project.
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Wetland and Riparian Habitat Assessment
3.0 STUDY AREA
The wetlands study area encompasses all four reservoirs under APGI management: High Rock,
Tuckertown, Narrows, and Falls (Figure 1-1). Upstream, the study area extended to the upstream
limit of the FERC Project boundary, approximately 1 mile north of Boone's Cave State Park on the
Yadkin mainstem. Similarly, on the South Yadkin River, the study area extended to the upstream
limit of the FERC Project boundary, approximately 6 miles from its confluence with the Yadkin
River. Downstream the study area extended approximately 1 mile below Falls Dam, which was
estimated to be the maximum extent of riverme flow in the Falls dam tailrace during low water on
Tillery Reservoir. In accordance with the study plan, all wetlands and riparian habitats within the
FERC Project boundary as well as all lands within 200 feet of the reservoir shorelines were included
in the study area. In addition, the study area was extended to include the zone of influence of
reservoir operations, which in a few places extended the study area beyond 200 feet.
The emergent wetlands on Narrows were assessed according to the distribution of piers constructed
since 1997. While the entire shoreline of Narrows was reviewed, the pier study focused on Heron
Bay and the northeastern arms of the reservoir where much of the new development has occurred.
4.0 STUDY PURPOSE AND OBJECTIVES
On March 13, and April 25, 2003 the Wetlands, Wildlife and Botanical IAG met and discussed
objectives for the wetlands and riparian habitat study. Over the course of those discussions the
following objectives were identified for the study.
¦ Identify and map vegetated wetlands and riparian habitats within the influence of reservoir
water levels, including aquatic beds, emergent and shrLb-wetlands and some forested wetlands.
¦ Evaluate effects of current Project operations, including reservoir water level fluctuations on
these wetlands and riparian habitats.
¦ Evaluate how significant changes in Project operations, including both increasing and
decreasing short-term and long-term reservoir drawdowns would impact existing wetlands, or
would allow for additional wetland development.
¦ Qualitatively assess the effects of reservoir facilities (such as piers, boat ramps, beaches,
bulkheads and other forms or shoreline hardening) on wetlands and riparian habitats, with a
particular emphasis on the potential impact of piers on water willow at Narrows
Reservoir.
The final study plan was distributed to the IAG in June 2003.
5.0 STUDY METHODS
5.1 HYDROLOGIC REGIME
To better understand the current hydrologic regime of the four Yadkin Project reservoirs, NAI
determined the minimum, mean and maximum daily water level elevations in each of the four Yadkin
reservoirs over a period of one year based on long-term records, as well as annual, monthly, weekly
and daily minima, means, maxima and ranges in water level elevations based on the same long-term
Wetland and Riparian Habitat Assessment
data record. The resulting summary of hydrologic conditions was used to assess the potential impact
of water level fluctuations on the aquatic and riparian habitats contained within each reservoir.
The reservoir elevation data for this investigation were provided by PB Power in the form of Excel
spreadsheets. Daily data were provided for the period of January 1, 1986 through December 31, 2003.
The water level data for Narrows from November 21 through December 26, 2003 were excluded from
the analysis because the reservoir was lowered 17 feet for the aquatic habitat survey (NAI 2004a).
The daily values do not represent a daily mean, but simply a "snapshot" view of water levels on each
day. Hourly data were provided for January 1, 1997 through December 31, 2003. The hourly data
provide the best resolution for this type of analysis, particularly when evaluating daily statistics, but
the seven-year period of record was not sufficient to adequately represent long-term averages. A
preliminary analysis to see how well the daily values match a daily mean calculated from the hourly
records was therefore conducted. For High Rock, Narrows and Tuckertown reservoirs, daily data
from January 1, 1997 through December 31, 2003 matched daily means calculated from hourly data
for that same time period extremely well'. In the Falls Reservoir, however, the relationship was
significant but with a weaker correlation (R2=0.51). The reason for this appears to be the greater
degree to which water levels fluctuate in the Falls reservoir on a daily basis compared to the other
reservoirs.
Since the annual, monthly and weekly statistics are based on a daily value (generally a daily mean),
these were generated using the longer period of record (1986-2003) using the daily values, which
were shown to provide a reasonable surrogate for daily means calculated from hourly values in three
of the four reservoirs. This same approach was used for the Falls Reservoir despite a weaker
correlation between hourly and daily data. An additional, more detailed comparison of each statistic
using daily and hourly data for just 1997-2003 was then conducted for the Falls reservoir, to provide
some judgment in interpreting the statistics generated from the long term daily records.
The 2004 water level data were processed separately from the 1986-2003 data to depict the water
levels during the time of the botanical and wildlife field work. Provided by PB Power, the values
were taken from the hourly data collected for midnight for each day. The 2004 data were compared
to the long-term daily mean, and the driest year for the period of record, 2002. Because 2004 was
extraordinarily wet during the latter part of the growing season, these years provide a broad spectrum
of reservoir water levels and environmental conditions.
5.2 MAP OF WETLANDS AND RIPARIAN HABITATS
5.2.1 Photointerpretation
In late July of 2003, true color aerial photographs were taken of the of the four-reservoir Project area
The aerials for the Upper Yadkin were flown on August 28, 2003. The resulting stereopairs, at a
scale of 1:9,600, showed aquatic and terrestrial vegetation at full leaf and water levels at or near full
pond in all four reservoirs. A total of 311 individual 9-inch by 9-inch photographs covered the
Project area in stereo at this scale, and delineations were made on approximately half of these.
A team of four scientists delineated upland and wetland cover types on these photographs using a
Sokkisha MS-27 mirror stereoscope with a 3X binocular and an Old Delft ODSS III mirror
' A simple linear regression of Y=X, where Y is the mean daily elevation based on hourly records and X is the
daily elevation from the daily records, resulted in R2 values of 0.88 to 0.99 for the High Rock, Narrows and
Tuckertown reservoirs.
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Wetland and Riparian Habitat Assessment
stereoscope with 1.5 to 4.5 magnification. Cover types were marked on clear acetate overlaid on the
photographs. On each photo, the delineators marked the apparent extent of full pond (shoreline),
represented by the edge of water or edge of woody or upland herbaceous vegetation along the
reservoir.
Wetlands were classified following the U. S. Fish and Wildlife Service method (Cowardin, et al.
1979). Mapping unit size for wetlands was 1/4 acre, or 100 ft by 100 ft (1/8 inch square on the
photos), and the labeled types included:
¦ PFOI - palustrine forested deciduous wetland,
¦ PFOlc - palustrine forested floodplain wetland, highly dependent on reservoir water levels,
¦ PSS1- palustrine scrub-shrub wetland,
¦ PSS1p- sparsely vegetated palustrine scrub-shrub wetland,
¦ PEM - palustrine emergent wetland,
¦ PUB - palustrine pond, unknown bottom,
¦ LEM - lacustrine emergent wetland (herbaceous wetland shoreline plants),
¦ LAB - lacustrine aquatic bed (submerged or floating leaved wetland plants),
¦ REM - riverine non-persistent emergent wetland,
¦ RAB - riverine aquatic bed, and
¦ OW - open water (reservoir or influenced by reservoir levels).
Several of these were combined into a common cover type in the final map. For instance, LAB and
RAB are depicted as AB (Aquatic Bed) because the microhabitat in which this cover type occurred
was more similar to a lacustrine condition (still water within the full pond line) even though several
beds occurred within riverine habitat. The same applies to PEM, LEM and REM which were
ultimately combined into a single EM (Emergent Marsh) cover type.
Terrestrial land use types within 200 feet of the shoreline and at least 400 feet long along the
shoreline (1/2 inch on the photos) were classified as follows:
¦ F - forest - including forestland in any stage of succession from recently cut to mature,
and including deciduous, coniferous and mixed forests,
¦ S - shrub, including areas, typically under powerlines, permanently maintained in the
shrub/sapling stage,
¦ G - urban/recreational grasslands - including parks, golf courses and very large
maintained lawns,
¦ Ap - agriculture, pasture - with no evidence of mowing or row crops,
¦ Ac - agriculture, crops - including row crops and hayfields,
Wetland and Riparian Habitat Assessment
R - residential, including small mowed yards, outbuildings, and small patches of natural
vegetation between houses,
¦ C - commercial/industrial, including adjacent parking areas, and
¦ M - bare soil or rock, mining, quarries, gravel pits.
Additional notations were made on each photo, including match lines, flightline and photo number,
control points (road intersections or other landmarks for matching to base maps), and question marks
for difficult areas where ground-truthing was deemed necessary.
During photo- interpretation, other resources were consulted for supporting information including
hydric soil maps, National Wetland Inventory maps, field notes and photos, and a set of black and
white stereo photos at a scale of 1:6,000 flown in March 1997. These photos were useful for
discerning conifers from deciduous trees and shrubs; persistent emergent vegetation from non-
persistent vegetation; soil drainage and topography under the canopy of forested wetlands; and other
details revealed at the larger scale.
5.2.2 Image Transfer and Mapping
Completed delineations were subjected to the Quality Control Procedure (see below), photocopied,
scanned, rubbersheeted/stiched together by a computer graphics expert and overlayed on electronic
color orthophotos flown in March 2002 of the Project area. The Project limits and the shoreline
within 200 feet of the reservoirs were established using a lakeshore polygon provided by PB Power
and based on the March 2002 orthophotos. Printouts of this product were then reviewed prior to
digitizing the cover type boundaries and developing a database using ArcView GIS versions 8.3 and
9.
APGI provided Normandeau with a GIS map of the reservoirs that had the shallow bathymetry
depicted in 2-foot contours. The contour limit for High Rock was approximately 12 feet below full
pond, 2 feet on Tuckertown, 17 feet on Narrows, and 2 feet on Falls. These contours were overlain
on the vegetation map. However the field assessment indicated that almost all of the vegetated
wetlands fell within the upper 3-5 feet of the reservoir beds, so the bathymetric contours were not
used. The contours were used as part of the estimate for the potential acreage of additional in-pond
vegetation during the analysis done to evaluate potential changes in reservoir water level regimes.
5.2.3 Office Quality Control Methods
Quality control (QC) was applied at several stages in the photo-interpretation process. As cover type
delineations of a photo flightline were completed, 30% to 100% of the flightline was reviewed by one
of the other delineating scientists for consistency and completeness. As errors, inconsistencies, or
differences of opinion were encountered, notations were made on the photos for revie w, discussion
and final modifications by the original delineator or a third delineator. Unresolved areas were marked
for ground-truthing.
After acetates were scanned and electronically stretched to the base map, a printout was reviewed by
a Senior advisor for completeness and consistency with delineation protocols. Cover-type boundaries
were traced and digitized, and a database and legend developed for each cover type. Each delineator
reviewed the portion of the printed cover type map for which he/she was responsible, and further
ground-truthing commenced.
Wetland and Riparian Habitat Assessment
5.3 FIELD SURVEY
Photointerpreted wetland cover types and locations were verified in the course of field work. Areas
of questionable identity were visited and the mapped lines and cover types evaluated and adjusted if
necessary. General wetland cover types were characterized by visiting multiple wetlands within a
given cover type and describing the plant community species composition and structure, soil
characteristics, soil moisture, and ground features such as amount of litter, rockiness, and
microtopography. Photointerpreted upland cover types were verified from the boat. These cover
types were not groundtruthed in detail, with the exception of upland forests in the vicinity of several
rare species habitats.
Ground-truthing visits were made to the Project area on several occasions, as listed below.
October 20-24, 2003 - Investigation of "new" emergent vegetation on High Rock Reservoir;
supplementary ground truthing of all High Rock Reservoir wetlands as viewed from the
water, and incidental ground-truthing of Narrows Reservoir.
December 17-19,2003 - Ground-truthing survey (primarily by boat) of wetlands around
Narrows Reservoir during drawdown to calibrate the signatures observed on the photographs
with the vegetation observed in the field, with particular attention to aquatic bed and
emergent communities. Also a survey of the riverine and bottomland reaches of High Rock
Reservoir was done.
2004 -Ground-truthing survey by boat and on foot of examples of all natural cover types
within the Project area to verify accuracy of the cover type map. Most shorelines of the
reservoirs were reviewed at least once during ground-truthing. Representative locations for
all cover types were intensively surveyed to determine the structure and composition of the
habitat. Three site visits were performed within the 2004 growing season to capture a broad
range of conditions:
• April 26 to May 4
• June 14 to June 22
• September 20 to October 3
Ground-truthing was performed by three senior field ecologists from Normandeau, who were
periodically accompanied by a local botanist, Dr. Peter Diamond, from the North Carolina Zoological
Park. Normandeau spent a total of 55 person-days in the field visiting representative cover types,
verifying the cover type map, and collecting water willow data. At the representative cover types,
data collected included plant species composition and abundance, wildlife observations, hydrologic
evidence (scour, sediment deposition, flood marks, saturation), and surficial substrate features
(stoniness, litter depth, coarse woody debris). Submerged aquatic vegetation was sampled using a
rake to determine presence and species composition. The extents of beds of submerged aquatic
vegetation were estimated in the office based on field notes and bathymetry because water clarity
prohibited aerial photo interpretation or mapping in the field.
In the office, the cover type maps were revised to reflect the ground-truthing results of the field work.
The final maps were subjected to another round of QC by an independent scientist reviewing sections
of each reservoir and comparing the field note annotations to the cover type map. The approved maps
Wetland and Riparian Habitat Assessment
were then analyzed in GIS (Arc View 9) to provide acreages of the various cover types in each
reservoir.
5.4 ANALYSIS OF PROJECT OPERATION
A combination of hydrologic information, reservoir bathymetry, and shoreline inspection were used
to assess the effects of current Project operations on natural resources around the reservoirs. Of
particular interest to the Wetlands, Wildlife and Botanical IAG were
¦ the effects of water level fluctuations on vegetation communities,
¦ erosion from boat wakes on bordering wetlands in coves,
¦ the impact of a sand-and-gravel extraction facility at the upper end of High Rock on nearby
wetland and riparian habitats, and
¦ the impacts of reservoir facilities and shoreline development on wetland and riparian habitats.
¦ a special emphasis was placed on the impact of piers on water willow beds in Narrows
Reservoir.
Water Willow
In the 2004 NAI study, the distribution of water willow on Narrows was delineated as part of the
cover type mapping. As described in the vegetation mapping methods section (Section 5.2), emergent
and submergent vegetation communities were mapped on all four reservoirs from true color aerial
photographs flown in mid-summer 2003, at a scale of 1:9600. Field verification of the mapped limits
and species composition of the cover types occurred throughout the growing season in 2004. While
the aerial photography was suitable for identifying the larger beds, it was less effective for detecting
small or narrow stands of emergent vegetation. These are beds that were typically less than 6 feet
wide, or occurred under trees overhanging the shoreline. To compensate for this difficulty, the cover
type maps were supplemented in the field by a more qualitative assessment that estimated the
percentage of the shoreline which supported water willow. As the shoreline was traveled, the
percentage of the shoreline that supported water willow was noted in general categories: 0%, 1-20%,
21-40%, 41-60%,61-80% and >80%. Almost 80% of the shoreline of Narrows was reviewed for this
purpose. In the office, the perimeter of the shoreline falling into each category was measured. The
beds were assumed to be 5 feet wide, and therefore the acreage of water willow formed by these small
beds could be estimated. These small beds are not shown on the cover type maps, but add
approximately 92 acres of emergent wetland on Narrows, or slightly more than the total mapped from
aerials.
The Wetland and Riparian Habitat Study Plan (2003) called for sampling a set of 15 "old" piers,
including the 5 studied by Touchette et al, (2001) and 15 "new" piers. The old piers were defined as
those piers constructed prior to 1997 as delineated by PB Power on a black-and-white orthophoto
dated March 1997. This delineation was laid over a true color orthophoto dated March 2002. Piers
that were not delineated were assumed to have been constructed after 1997 and therefore were
defined as new. The new piers were overlain on the cover type map and those that fell within water
willow beds were identified as potentially suitable for the water willow site work. Approximately 20
piers were identified in the office prior to field work. All of these piers were located in Heron Bay,
Gladys Fork and Reynolds Creek.
Wetland and Riparian Habitat Assessment
The field work for the water willow pier study occurred in late September 2004. The new piers
identified in the office were visually located from the boat using shoreline configurations and other
piers. Only piers which were located in beds of water willow or in potential water willow habitat
were sampled. In many instances, some or all aquatic vegetation had been cleared adjacent to the
dock and in front of other shoreline structures (retaining walls, boat launch ramps, boat houses, etc).
These docks were kept in the study if water willow beds were robust on at least one side of the pier.
Fifteen new piers were studied. At each pier, the study area was defined as within 20 feet of both
sides of the pier, which is similar to the &m width of the study area of Touchette et al. 2001. Data
collection included many features of the water willow bed, the dock and the adjacent shoreline. A
sample form is provided in Figure 5.4-1. Key parameters included the length, width and water depth
of the water willow bed on either side of the pier, the height and width of the pier within the water
willow bed, land use features such as shoreline structures, if any, and management of the aquatic bed,
if apparent. The permit number for each dock was recorded, which allowed us to collect information
from APGI on the history of the pier, thus the date the pier was built or modified was available as a
final check on the age of the pier. The permits for two piers indicated that they had been built or
substantially modified before 1997, however the photos and field indicators suggested that recent
disturbance or construction had occurred so these piers were retained as new in the study.
For the old piers (constructed prior to March 1997) and several additional new piers encountered after
the fifteen were completed, data collection was more qualitative. The percent cover of water willow
adjacent to, and under, the pier was estimated visually. The permit number and photodocumentation
were taken, and the pier, other shoreline structures and impacts to water willow were described. In
some instances, water willow bed characteristics such as width, percent cover and water depths were
measured.
5.5 EFFECT OF ALTERED PROJECT OPERATION
One of the objectives of this study was to evaluate the potential impact to Project wetlands associated
with altered reservoir water level regimes. The wetlands likely to be most affected by changes in the
hydrologic regime are those that are strongly influenced by the current hydrology of the reservoirs.
These include all wetlands occurring within the full pond limit of the reservoirs, and those bordering
the shoreline that are low enough in elevation to be seasonally affected by changes in reservoir water
levels. The cover types included aquatic beds, emergent wetlands, sparse scrub-shrub swamps, scrub-
shrub swamps that occur along the edge of the reservoirs, and forested floodplain wetland. The only
wetland cover type excluded from this analysis was the forested wetland, because this wetland type
typically had a hydrologic regime that was less influenced by reservoir hydrology than by
groundwater or other surface water (tributary streams or small ponds). All upland cover types were
assumed to be unaffected.
The analysis was conducted using several simplified water level regimes that were developed to
encompass the range of operational alternatives that are being considered in the relicensing. The
water level alternatives evaluated included:
Wetland and Riparian Habitat Assessment
Yadkin Water Willow/Dock Survey Form
Sample Label
Location
Date_
Permit No.
Water Willow Bed
Width: L
R
Exposure bearing
%Cover: L
R
Length: L
R
Fetch
Height: L_
R
Water depth:
Inner L Outer: L
R R
Substrates
Shoreline morphology
Other species
Dock
Length Width
Shoreline structures
Shallow water use
Shoreline vegetation: Canopy closure & structure
Understory
GPS coordinates: N W
Sketch
Figure 5.41. Data collection form for water willow study.
Height above full pond
Average: L
R
Photos
10
Wetland and Riparian Habitat Assessment
¦ High Rock- three alternative water level regimes (Figure 5.5-1):
¦ Alternative 1 - Near-Full Year Round; reservoir maintained within 3 feet of full
year round;
Alternative 2 Extended Near Full Season; a 10-foot average drawdown, similar to
existing conditions but a longer full pond period, refilling in March rather than April
and drawing down in November rather than mid-September;
Alternative 3 - Additional Use of Storage; drawing down 20 feet on average, with
the same refill and drawdown schedule as existing, but refilling to within 5 feet of
full pond (618.9 feet USGS, 650.0 feet Yadkin datum).
¦ Tuckertown - Increased Short Term Fluctuations - short-term reservoir fluctuations are
increased to 3-5 feet, compared to the current 1-2 feet.
¦ Narrows - Additional Use of Storage - no large water level changes, but winter
drawdown increased to 15 feet, and summer fluctuations more routine
and deeper (5-10 feet).
¦ Falls - No water level changes were examined
While all of the existing wetlands were observed to occur within the upper 5-6 feet in all the
reservoirs, the acreage of additional potential wetlands under the various hydrologic alternatives were
estimated from the 2-foot bathymetric contour intervals. These data were evaluated for potential
changes in species composition, structure and function, particularly to fish and wildlife for each cover
type for the three hydrologic alternatives on each reservoir.
6.0 LANDSCAPE SETTING
6.1 VEGETATION
According to the ecoregion classification of the USDA Forest Service (1994), the Yadkin Project area
lies within the Southern Appalachian Piedmont Section of the Southeastern Mixed Forest Province,
Subtropical Division of the Humid Temperate Domain. The Piedmont landscape constitutes an
irregular plain of ancient, chiefly pre-Cambrian and Palaeozoic rock that has disintegrated in place
and received additional unconsolidated material from higher ground to the west. This plain ranges in
elevation between about 250 feet and 1,100 feet in the Project area and immediate environs, the result
of differential erosion that has produced occasional isolated heights (e.g. Bald Mountain) and
moderately incised waterways. Erosion of the generally deep soils has been greatly accelerated by
the past two centuries of intensive agriculture, chiefly for cotton. Average annual precipitation ranges
from 45 to 55 inches. Temperature averages about 60 degrees F. The growing season lasts over 200
days. Natural vegetation in a relatively undisturbed condition supports deciduous and evergreen trees
in roughly equal proportions. The Yadkin River is one of the principal rivers of this geographic
Section.
6.2 SUBSTRATES
Within the reservoirs, the vast majority of the substrates exposed during drawdown were classified as
mud/sand/clay during the aquatic habitat surveys performed as part of the FERC relicensing effort
(Normandeau 2004a). This was consistent with field observations in which mineral fines were the
11
N
High Rock Water Level Scenarios
660
655
0
>- 650
a?
J
?-) 645
Y
U
O
640
LM
635
630
1/1
1/31 3/2 4/1 5/2 6/1 7/2 8/1 9/1 10/1 11 /1
Date
-m-"Existing Conditions" *Alt 1 Alt 2 Alta Normal Full Pond
Figure 5.5-1. High Rock water level scenarios provided by APGI.
12/1 1/1
CD
as
Q
Q

01
a
n
y
y
CD
C4
C4
CD
ti.
Wetland and Riparian Habitat Assessment
dominant substrate type in both the vegetated and unvegetated shallows. Several notable exceptions
occur on Tuckertown and Falls where ledge and rock were the prevalent shallow substrate along steep
shoreline sections. On High Rock, boulders, ledge, cobble and gravel collectively composed less than
2% of the substrate in the drawdown zone. Artificially-placed items such as trees, stumps, and tires
which are placed by agencies and home owners to provide fish habitat as well as docks, riprap and
other shoreline structures occupied another 2.5% of High Rock's drawdown zone.
Within 200 feet of the reservoirs, the soils are primarily formed from residuum weathered from fine-
grained metamorphic rock or igneous pyroclastic rocks such as Carolina slate, phyllite or sericite
schist. The riverine system upstream of the reservoirs is dominated by moderately broad, nearly level
floodplains adjacent to the river. The side slopes of the reservoirs are generally steep with slopes
ranging from 8 to 45%. Depth to bedrock is variable ranging from exposed outcrops to greater than
40 inches in depth. Common soils within the uplands include Appling sandy loam, Enon fine sandy
loam, Wedowee sandy loam, Pacolet sandy loam, and Pacolet sandy clay loam. The degree of surface
boulders varies within the Study Area with the majority of soils having few surface boulders
compared to the Uwharrie stony silt loam, which has slopes ranging from 15 to 45%, and is very
bouldery.
Table 6.2-1 provides a summary of hydric soils that potentially may occur within the Project Area. "A
hydric soil is a soil that formed under conditions of saturation, flooding, or ponding long enough
during the growing season to develop anaerobic conditions in the upper part" (Federal Register, July
13, 1994, http://soils.usda.gov/use/hydnc/ntchs/tech notes/notel.html, December 14, 2004). Hydric
soils are used as one of the parameters in defining wetlands according to the 1987 Corps of Engineers
Wetlands Delineation Manual.
Table 6.2-1. Summary of hydric soils that may occur within the Project Area.
Map Unit Name Hydric inclusions 1 Normal Location Flood Frequency
Altavista sandy loam 1 Depressions adjoining uplands Occasionally
Armenia silt loam2 1,3 Depressions Occasionally
Chewacla loam 1 Adjoining upland sideslo es Frequently
Cid-Li num Complex 1 Depressions, along draina ewa s
Helena sandy loam 1 Depressions, along drainageways
Iredell loam 1,3 Depressions
Kirksey-Cid Complex 1 Depressions
Lignum silt loam 1 Depressions, along drainageways
Oakboro silt loam 1 Depressions, along draina ewa s Frequently
Roanoke loam 1 Occasionally
Sedgefield fine sandy loam 1 Depressions, along drainageways
Wahee loam 1,3 De ressons, along draina ewa s Occasionally Hydric codes:
1. Hydric soils only because of saturation for a significant period during the growing season.
2. Hydric soils that are frequently flooded for long or very long periods during the growing season.
3. Hydric soils that are ponded for long or very long periods during the growing season.
2 Bolded map units are all hydric or have hydric soils as a major component. Plain text map units have inclusions of hydric
soils or have wet spots.
13
Wetland and Riparian Habitat Assessment
6.3 HYDROLOGIC REGIME
6.3.1 Long-term Water Levels
High Rock Reservoir
Daily water levels in the High Rock reservoir over thel8-year period of record are plotted in Figure
6.3-1. Full-pond elevations have occurred during all months of the year, though more frequently
during late winter and early spring. Water levels in the reservoir were generally highest during the
spring and declined as summer progressed, with the lowest daily values observed in July and August.
Out of the four reservoirs in the Yadkin system, High Rock exhibited the greatest range in elevation
on an annual basis (Table 6.3-1). On the shorter time scales, however, elevations varied to a similar or
lesser extent than in the other reservoirs, and declined to zero at the weekly and daily time scales.
Tuckertown Reservoir
Daily elevations in the Tuckertown reservoir exhibited a less distinct seasonality compared to the
High Rock reservoir (Figure 6.3-2), although minimum elevations on the monthly, weekly and daily
time scales also occurred during July (Table 6.3-1). Overall, elevations within the Tuckertown
reservoir were the most stable and exhibited the smallest range of variation of each of the four
reservoirs, on all time scales except for the daily range.
Narrows Reservoir
The Narrows reservoir showed a greater degree of seasonal change compared to Tuckertown and
Falls, but less than that observed in High Rock (Figure 6.3-3). On average the reservoir water levels
were highest in late March through April, then declined to a September low. Refill occurred through
the fall and early winter. Minimum water levels were observed in late winter and late summer, with
reservoir maxima at full pond almost continuously from mid-January through early May.
Falls Reservoir
Although water levels in the Falls reservoir showed the highest degree of daily, weekly and monthly
variability (Table 6.3-1), overall there was no discernible seasonal pattern apparent in the long term
daily records (Figure 6.3-4). Extreme low water events in March 1998, September 1993 and mid-
October in 1988 were the source of the most of the minimum values observed on each time scale
examined. A further analysis of how well results using the daily values compared to those generated
from daily means based on hourly data for the Falls reservoir was conducted, since initial analyses
indicated that the relationship between the two was not as strong as for the other three reservoirs.
Looking just at 1997-2003, there were few differences in the results using the two different sets of
records on an annual, monthly and weekly basis (Table 6.3-2). In fact, results for the shorter period
of record, whether for daily or hourly data, were not substantially different than those based on the 18
year period of daily records.
6.3.2. 2004 Water Levels
Most of the field work for the wetland and terrestrial habitat evaluations was performed in 2004. To
provide some perspective on the hydrologic conditions observed during field work, the daily water
levels in 2004 (January to October) were overlain on the historical daily mean water levels for the
period January 1986 to October 2004, along with the daily water levels recorded in 2002 (Figures 6.3-
5 to 6.3-8). 2002 data were included because of the extremely low flows observed in that year
compared to the above-average flows of 2004. Water levels in the Yadkin Project reservoirs varied in
response to changes in their storage, which is dependent upon changes in their inflow and outflow.
14
v,
Table 6.3-1. Summary of water elevations (feet USGS) statistics in the Yadldn reservoirs based on daily data (1986-2003)' and hourly
data (1997-2003)b.
RESERVOIR (Normal Full Pond Elevation)
Time Scale High Rock (623.9 FT) Tuckertown (564.7 FT) Narrows (509.8 FT) Falls (332.8 FT)
Statistic Date(s) Statistic Date(s) Statistic Date(s) Statistic Date(s)
Annual Range'
Minimum 8.83 1990 1.60 1988 2.19 1989 2.60 1994
Mean 13.49 2.42 4.09 5.90
Maximum 23.62 2002 3.30 2000 11.92 2002 17.83 1998
Monthly Range'
Minimum 0.88 Jun-99 0.25 * 0.30 Feb-98 0.57 Jul-87
Mean 4.38 1.22 1.50 2.01
Maximum 15.66 Feb-89 2.90 Mar-91 8.07 Oct-95 17.67 Mar-98
Monthly Elevation'
Minimum 599.86 Jul-02 561.38 Jul-00 497.82 Aug-02 314.80
Mean 618.87 563.75 508.23 331.47
Maximum 623.90 * 564.70 * 510.30 Oct-90 332.80
Weekly Range'
Minimum 0.00 * 0.00 * 0.00 * 0.00
Mean 1.62 0.60 0.59 1.13
Maximum 10.35 29-31 Dec-96 2.90 3-9 Mar-91 8.07 1-7 Oct-95 17.51 1-7 Mar-98
Weekly Elevation'
Minimum 599.86 14-20 Jul-02 561.38 2-8 Jul-00 497.82 25-31 Aug-02 314.80
Mean 618.84 563.75 508.22 331.47
Maximum 623.90 * 564.70 * 510.30 14-20 Oct-90 332.80
Daily Rangeb
Minimum 0.00 * 0.00 * 0.00 * 0.00
Mean 0.38 0.32 0.20 1.09
Maximum 4.02 15 Feb-97 2.68 14 Jun-00 1.60 21Mar-03 17.51 6 Mar-98
Daily Elevation
Minimum 599.82 20 Jul-02 561.38 8-9 Jul-00 497.71 31 Aug-02 314.80
Mean 618.28 563.70 508.22 331.54
Maximum 623.90 ** 564.77 10 Jan-00 509.91 29 Aug-02 332.90 20 Mar-03
(DD
Q
Q

01
a
n
y
y
fD
C4
y
fD
Occurred more than once during period of record.
Occurred multiple times between 24 April and 4 May 1997,28-31 January 1998, 5-7 February 1998,10-13 March 1998,18-25 April 1998, 8-12 May 1998, and on
several dates in March, April, July, August and September of 2003.
Wetland and Riparian Habitat Assessment
690
625t-- ----- FULL POND ---
6Z0
F-
LL
c
615
N
LU
610
6051
eooi
Jan l Feb l Mar l Apr l May l Jun j Jul l Aug l Sep l Oct l Nov IDec l
Mirimum Daily\/alue
Mean Daily\/alue
Mabmun DailyValue
Figure 6.3-1. Minimum, mean and maximum daily water level elevations (USGS datum) in
High Rock Reservoir for the period of January 1, 1986 to December 31, 2003.
586
565 FULL FOND
564
F-
LL
c
O cs3
N
LU
562
5611
5601
Jan IFeb l Marl Apr IMay l Jun I Jul l Aug l Sep l Oct l Nov l Dec l
Mirimum Daily\/alue
Mean Daily\/alue
Mabmun Daily\/alue
Figure 6.3-2. Minimum, mean and maximum daily water level elevations (USGS datum) in
Tuckertown Reservoir for the period of January 1, 1986 to December 31, 2003.
16
Wetland and Riparian Habitat Assessment
jA PaIED
u_
0
w
Jan j Feb IMar l Apr IMay l Jun I Jul j Aug j Sep j Oct I Nov j Dec l
Mirimum Daily\/alue
Mean Daily\/alue
Ma arum Daily\/alue
Figure 6.3-3. Minimum, mean and maximum daily water level elevations (USGS datum) in
Narrows Reservoir for the period of January 1, 1986 to December 31, 2003.
FULL POND
------------------------------------------------------------
u_
°- 331
W
Jan j Feb IMar l Apr IMay l Jun I Jul j Aug j Sep j Oct I Nov j Dec l
Mirimum DailyValue
Mean DailyValue
Mabmun DailyValue
Figure 6.3-4. Minimum, mean and maximum daily water level elevations (USGS datum) in
the Falls Reservoir for the period of January 1, 1986 to December 31, 2003.
17
Wetland and Riparian Habitat Assessment
Table 6.3-2. Comparison of water elevation analyses for Falls Reservoir using daily and hourly
data for the period of 1997-2003.
DATASOURCE
Time Scale Daily Records Hourly Records
Statistic Date(s) Statistic Date(s)
Annual Range
Minimum 2.86 1997 3.33 1997
Mean 5.63 6.10
Maximum 17.83 1998 17.99 1998
Monthly Range
Minimum 0.62 Mar-97 1.00 Jan-97
Mean 2.35 3.19
Maximum 17.67 Mar-98 17.94 Mar-98
Monthly Elevation
Minimum 314.80 Mar-98 314.80 Mar-98
Mean 331.53 331.55
Maximum 332.80 Apr-O 1 332.90 Mar-03
Weekly Range
Minimum 0.15 26 Jan- 1 Feb-97 0.15 26 Jan- 1 Feb-97
Mean 2.28 2.28
Maximum 17.66 1-7 Mar-98 17.66 1-7 Mar-98
Weekly Elevation
Minimum 314.80 1-7 Mar-98 314.80 1-7 Mar-98
Mean 331.54 331.54
Maximum 332.90 16-22 Mar-03 332.90 16-22 Mar-03
18
Wetland and Riparian Habitat Assessment
690
625
620
H
LL
c
615
N
LU
610-
605-1
6001
FULL FOND
Jan I Feb l Marl Apr l May l Jun j Jul l Aug l Sep l Oct l Nov l Dec l
2002 Daily Elevation
2004 Daily Elevation
Historical Daily Mean
Figure 6.3-5. Comparison of 2004 water level elevations (USGS datum) with longterm mean,
and 2002 drought at High Rock Reservoir.
586
565
564
H
LL
c
O cs3
N
LU
562
5611
5801
Jan I Feb l Marl Apr l May l Jun j Jul l Aug l Sep l Oct l Nov l Dec l
2002 Daily Elevation
2004 Daily Elevation
Historical Daily Mean
Figure 6.3-6. Comparison of 2004 water level elevations (USGS datum) with long-term mean,
and 2002 drought at Tuckertown Reservoir.
19
FULL FOND
-----------------------------------------------------------
Wetland and Riparian Habitat Assessment
512
510
50B
H
LL
c
O ms
N
LU
534-
5M-1
5001
FULL FOND
Jan I Feb l Marl Apr l May l Jun j Jul l Aug l Sep l Oct l Nov l Dec l
2002 Daily Elevation
2004 Daily Elevation
Historical Daily Mean
Figure 6.3-7. Comparison of 2004 water level elevations (USGS datum) with longterm mean,
and 2002 drought at Narrows Reservoir.
34
33
3i2
H
LL
c
31
N
LU
3'0
FULL FOND
391
381
Jan I Feb l Marl Apr l May l Jun j Jul l Aug l Sep l Oct l Nov l Dec l
2002 Daily Elevation
2004 Daily Elevation
Historical Daily Mean
Figure 6.3-8. Comparison of 2004 water level elevations (USGS datum) with long-term mean,
and 2002 drought at Falls Reservoir.
20
Wetland and Riparian Habitat Assessment
Factors controlling inflow included streamflow from tributary streams and for the three downstream
reservoirs, the hydropower operations, which also controls the outflow from each of the reservoirs.
When compared with the three downstream reservoirs, High Rock has experienced the greatest range
in daily mean water levels over the period of a year (Figure 6.3-5). This is due to its dependence on
inflows from the Yadkin River and its large storage volume (234,100 ac-ft.) for hydropower
production. During the study period (June 1999 to October 2004), below normal inflows to High
Rock Reservoir were experienced from mid-1999 to the beginning of 2003. The USGS (2003) has
noted that streamflow conditions in North Carolina were below normal for the water years 1998 to
2003, when below average precipitation was recorded in drainages across the state. The lowest water
levels recorded in High Rock Reservoir, during the study period, occurred during the summer months
of 2002, with water levels up to 19.5 feet lower than the historical daily mean. The decline in water
levels beginning in May 2002 and into July 2002 reflects the decline in inflow from its major
contributing drainages, the South Yadkin River and the Yadkin River. During the 2002 water year
(October 2001 to October 2002) historical low annual mean flows were recorded for both of these
drainages. The annual mean flows for both the South Yadkin River and the Yadkin River in 2002
were roughly one third their period of record annual means. The water levels slowly rebounded in
late 2002 to above average in response to increased precipitation and inflows.
In 2004, when the wetlands and terrestrial studies were performed, water levels in High Rock
Reservoir were, for the majority of the year first quarter of the year, at or below the historical daily
mean (Figure 6.3-5). This was in response to lower than average inflows. From May to October, in
response to higher inflows, water levels in the High Rock Reservoir were higher than average.
Of the three remaining reservoirs, only Narrows experienced prolonged below normal water levels in
2002 (Figure 6.3-7). While only half the size of High Rock Reservoir, Narrows storage volume
(129,100 ac-ft) is 19 times larger than Tuckertown (6,700 ac-ft) and 31 times larger than Falls (4,190
ac-ft). Lower than average water levels were experienced at Narrows in the summer of 2002. Water
levels during this period were up to 6.5 feet lower than the historical daily mean. As mentioned
previously, these low water levels were in response to below normal streamflow conditions in the
drainage basin and the required downstream releases in accordance with the Drought Contingency
Plan. z In 2004, water levels at Narrows were generally above the historical daily mean, except for
short periods in the winter months (January through March).
The Tuckertown and Falls Reservoirs are relatively small impoundments and have minimal storage
compared with High Rock and Narrows. As a result, the water levels in these reservoirs vary over a
limited range, four feet or less at Tuckertown and three feet or less at Falls (Figures 6.3-6 and 6.3-8).
In addition, extended periods of below or above average water levels are absent, although the
frequency of water level changes is much greater at both of these reservoirs.
7.0 SUMMARY OF EXISTING STUDIES AND INFORMATION ON THE
PROJECT AREA
In the last several decades, natural areas inventories for Rowan County (Baranski 1994) and for the
Yadkin River corridor (Baranski 1993) have occurred. These studies have included floristic studies
and descriptions of portions of the Yadkin Reservoirs, as did a management plan for the Uwharrie
2 APGI in cooperation with NC, SC and Progress Energy prepared and implemented a Drought Contingency
Plan during the summer of 2002.
21
Wetland and Riparian Habitat Assessment
National Forest (USFW 1986). The Uwharrie National Forest also recently completed a botanical
survey (Sharp, 2004)
Three previous studies of water willow on Narrows Reservoir have occurred since 1997. The first is
a study by Boaze (1997) which characterized the distribution of water willow on Narrows, on the
basis of one map in 1991 and a second survey later in the 1990's. A second study was completed as
part of the Narrows and Falls Reservoirs Shoreline Management Plan (Yadkin 1999). This study
included a less detailed map of "emergent/submergent wetlands", which one can assume were
dominated by water willow. In a third study performed by North Carolina State University, water
willow was field mapped and sampled for productivity, water quality parameters, distribution relative
to exposure and adjacent shoreline land use, and the effects of boat docks and piers (Touchette et al.
2001). This study also included an assessment of fish communities within and immediately adjacent
to the water willow beds
Of key interest to the present assessment are the water willow distribution results of the three studies.
While all three studies yielded similar results, Touchette et al (2001) gave the most detailed
breakdown of the distribution of water willow on Narrows. These authors identified three areas
supporting the largest stands of water willow: Heron Bay, the southwestern cove of Narrows, and the
Yadkin River below Tuckertown dam. Other areas of abundant water willow include Garr Creek,
Gladys Fork and Reynolds Creek. The shoreline along the Uwharrie National Forest supported
relatively small stands of water willow, primarily due to its steep slope.
The effects of piers on water willow were examined by Touchette et al. (2001) at five piers that had
well developed water willow beds on both sides of the pier. Parameters measured included dock
height, dock width, percent light transmission, shoot density, above- and below-ground plant
biomass, and mean plant weight. Light transmission and the plant characteristics were measured
adjacent to the dock, and at 2-m intervals to 8 in distance on both sides of the piers. Their study
found that water willow occurrence could be strongly correlated with light availability. On average,
light transmissivity was 10% of full intensity underneath the piers, increased to 70% at 2 in from the
piers, and was up to 80-90% at 4-8 in from the piers. Plant productivity followed the trends in light
availability, with no plants occurring under the docks, and the highest productivity at 4-8 in. At 2 m,
the productivity was somewhat less than at 4-8 in. The authors estimated that little water willow
growth occurred at light transmission of less than 60%.
8.0 EXISTING CONDITIONS
8.1 VEGETATION CHARACTERIZATION
The cover types around the four reservoirs were very similar in species composition and structure.
Slope, aspect and surficial geology were more important determinants than water body, with the
exception of the riverine sections above High Rock. Here, river processes are the dominant influence
on the formation of wetlands, and have resulted in a sub-type of floodplain wetland distinct from
those of the reservoirs. This distinction aside, in general, the cover type descriptions are common to
the entire Project Area (Figures 8.1-1 through 8.1-5; Table 8.1-1).
8.1.1 Palustrine Forested Wetlands
This wetland type occurred above the full pond line, typically small in area and associated with small
streams or the upper reaches of larger streams. Often linear in shape as they bordered a stream, the
hydrology of these wetlands within 200 feet of the reservoir was a combination of groundwater,
22
Wetland and Riparian Habitat Assessment
Ism
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Figure 8.1-1. Cover types within the 200-foot Project Area on Upper High Rock Reservoir.
23
Wetland and Riparian Habitat Assessment
r figure u. i-/-. cover types imutin ute /-uu-loot rrojecr Area on ute central ?,ecuon of reign xocx reservoir.
24
Wetland and Riparian Habitat Assessment
Figure 8.1-3. Cover types within 200-toot Project Area on Lower High Rock Reservoir.
25
Wetland and Riparian Habitat Assessment
Figure 8.1-4. Cover types within 200-foot Project Area on Tuckertown Reservoir.
26
Wetland and Riparian Habitat Assessment
Figure 8.1-5. Cover types within 200-foot Project Area on Narrows and Falls Reservoirs.
27
Q
71
° Table 8.1-1. Summary of acreages for cover types within 200 feet of Yadkin reservoirs.

High Rock Tuckertown Narrows
acres % acres % acres %

Falls
acres

%

Falls Tailrace
acres %
9
0) Wetland
0
0 Forested wetland 234 2.1% 64 3.2% 51 2.2% <1 0.2% 6 8.7%
0 Forested floodplain wetland 2194 19.7% 86 4.3% 40 1.7% <1 0.4%
Scrub-shrub wetland 325 2.9% 40 2.0% 4 0.2% <1 0.2% <1 0.5%
Sparse scrub-shrub wetland 484 4.3% 4 0.2% 0.0%
Emergent marsh 28 0.3% 45 2.2% 179 7.5% 3 1.5% 2 2.6%
Aquatic bed 3 0.0% 14 0.7% 60 2.5%
Upland
Forested 4796 43.0% 1597 79.6% 1242 52.2% 159 93.0% 59 87.3%
Grassland 106 1.0% 16 0.8% 50 2.1%
Agricultural cropland 372 3.3% 34 1.7% 4 0.1%
Agriculture pasture 84 0.8% 72 3.6% 0.0%
N Mineral 9 0.1% 3 0.2% <1 0.0% 5 2.8% <1 0.5%
Oc Residential
2401 0
21.5%
27 0
1.3%
731 0
30.7%
Commercial/Industrial 107 1.0% 5 0.2% 20 0.9% 2 1.2%
Total 11143 100.0% 2008 100.0% 2381 100.0% 170 98.9% 68 100.00/0
*includes 86.2 acres of photointe rpreted emergent marshes, and 92 acres e stimated during field surveys.
(DD
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Q
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Q
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y
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Wetland and Riparian Habitat Assessment
streamflow, and reservoir water levels. Within the wetland a strong moisture gradient was evident,
running from annual floodplain along the stream bank and reservoir edge to a transitional wetland on
the upland edge. In areas of steep topography, this gradient occurred within a short distance, creating
high variability within the wetland plant community. This cover type was common around all of the
reservoirs and was a dominant cover type, with the exception of High Rock where the floodplains on
the upper portion of the reservoir formed the vast majority of all wetlands (Table 8.1-1).
Despite the variability in terrain and drainage, the dominant tree species in the palustrine forested
wetland were fairly uniform: sweet gum (Liquidambar styraxiflua), sycamore (Platanus
occidentalis), red maple (Acer rubrum), river birch (Betula nigra) and overcup oak (Quercus lyrata),
among others (Table 8.1-2). The understory structure was more variable, responding to light
availability, soil moisture and soil chemistry. The shrub layer was often sparse, with common shrub
species including silky dogwood (Corpus amomum), and the invasive bush honeysuckle (LoniceraX
Bella). Poison ivy (Rhus radicans) and yellow jessamine (Gelsemium sempervirens) were dominant
lianas(vines). Species variability was highest in the herb layer as this layer is even more responsive
to microsite conditions. Dominants included lizards tail (Saururus cernuus) at the water's edge,
several sedges (Carex crinita, C. lupulina and C. tribuloides), spotted touch-me-not (Impatiens
capensis), and the invasive browntop (Microstegium vimineum). Indian sea oats (Chasmantheum
latifolium) frequently dominated the transitional area to upland if sufficient light was available.
8.1.2 Palustrine Forested Floodplain Wetlands
This cover type had two distinct habits in the study area. The most abundant was confined to the
deltaic section of upper High Rock reservoir where large quantities of sediment are deposited (Figure
8.1-2; Table 8.1-1). Large deposits of silt and sand have been accreting in this area for decades, on
which vegetation colonizes when the elevation and stability of the bar is adequate. Without
vegetation, the bars are very dynamic, changing shape and location with storm and water levels. With
vegetation, the bars become more stable, which establishes a positive feedback cycle of more
accretion and stability which allows vegetation to expand and mature, which further enhances
sediment accretion and stability. In this wetland type, black willow (Salix nigra) was the sole
dominant in both the tree layer and the shrub layer as a young sprout. Occasional sycamore and red
maple were also observed. The herb layer was also limited in both diversity and distribution,
developing a tenuous hold on the unstable and wettest downstream tips of newly forming bars.
Annuals dominate here, including smartweeds (Polygonum lapathifolium and others) and beggar's
ticks (Bidens frondosa).
A second variation of the forested floodplain wetland occurred along low-lying lands adjacent to the
reservoirs. These were often associated with historic stream terraces which still flood during high
flow events. The hydrologic forces of deposition, and occasionally scour, were visible as sediment
deposits and a thin litter layer over stratified mineral soils. Along the larger streams, frequent
overbank flooding has resulted in the formation of levees. These features were most pronounced
along the Upper Yadkin mainstem and the South Yadkin River where the levees were several feet
higher in elevation than the surrounding floodplain wetland, and supported upland plant communities.
(Because of their narrow, linear nature, the levees were included in the dominant cover type behind
them). Clearly significant flood events still occur during periods of high river flows on these two
rivers within the Project Area. Water stains and flood debris were visible in trees 10 feet above the
floodplain floor. Evidence of this level of flooding was not observed on the lacustrine portions of the
29
Wetland and Riparian Habitat Assessment
Table 8.1-2. List of dominant plant species by habitat on Yadkin Project Area.

Plant Layer & Species
Common Name ILL
w
-1?
TREES
Acer rubrum Red Maple D X X X
Acer saccharinum Silver Maple D D X
Acer saccharum leucoderme Chalk Sugar Maple D
Aesculus sylvatica Painted Buckeye X D
Betula nigra River Birch D X X X X
Carpinus caroliniana American Hornbeam x X D
Carya cordiformis BitternutHickory X D
Carya glabra Pignut Hickory D
Carya tomentosa MockernutHickory D
Cornus jlorida Flowering Dogwood x X
Fraxinus pennsylvanica Green Ash D D X X
Liquidambar styracijlua Sweet Gum D D X X
Liriodendron tulipifera Tulip Tree x X D
Nyssa sylvatica Black Gum D
Oxydendrum arboreum Sourwood X D
Pinus echinata Short -leaf Pine D
Pinus taeda Loblolly Pine D
Pinus virginiana Virginia Pine X D
Platanus occidentalis American Sycamore D D X
Populus deltoides Cottonwood D X X X D
Prunus serotina Black Cherry D
Quercus alba White Oak X D D
Quercus falcata Southern Red Oak x X D
Quercus lyrata Overcup Oak D D X
Quercus phellos Willow Oak D D X
Quercusprinus (Q. montana) Chestnut Oak X D
Salix nigra Black Willow X D D D X X
Ulmus alata Winged Elm X

SHRUBS
Cephalanthus occidentalis Buttonbush x X D D X
Cornus amomum Silky Dogwood D X D X
Ligustrum sinense Chinese Privet X D X
Lonicera x Bella Bush Honeysuckle D D
Rosa wichuraiana Memorial Rose D
Vaccinium arboreum Farkleberry D
Vaccinium stamineum Deerberry D

LIANAS
Campsis radicans Trumpet Creeper x X D
Gelsemium sempervirens Yellow Jessamine D D
Lonicera japonica Japanese Honeysuckle x X D
Parthenocissus quinquefoha Virginia Creeper X D X
Puerarza lobata Kudzu D
Rhus radicans Poison Ivy D D X
Vitis sp. Grape species X D X

(continued)
30
Wetland and Riparian Habitat Assessment
Table 8.1-2. (Continued)
Plant Layer & Species Common Name W
HERBS
Hexastylis arifolium Arum-leaved Heartleaf D
Aneilema keisak MarshDewflower D
Arisaema cf triphyllum Swamp Jack-in-the-
Pulpit D X X
Arundinaria gigantea Cane x X
Asplenium platyneuron Ebony Spleenwort D
Aster cf. lateriflorus Calico Aster x X X
Aster cf. vimineus Small White Aster X D
Bidens frondosa Devil's Beggar-ticks D
Boehmeria cylindrica Small-spike False Nettle D
Carex crinita Fringed Sedge D X
Carex lupulina Hop Sedge D X D
Carex pensylvanica Pennsylvania Sedge D
Carex tribuloides Blunt Broom Sedge D X X
Chasmanthium latifolium Indian sea oats x
Chimaphila maculata Spotted Wintergreen x X
Coreopsis verticillata Verticillate Tickseed D
Eleocharis obtusa Blunt Spikerush D
Elymus virginicus Virginia Wild Rye D X X
Eupatorium rugosum White Snakeroot x X X
Glechoma hederacea Gill-over-the-ground D X
Heterotheca (Pityopsis) graminifolia Grass-leaved Golden-
aster D
Hibiscus moscheutos Swamp Rosemallow x X D
Hieracium venosum Veined Hawkweed D
Houstonia caerulea Bluets X D
Impatiens capensis Spotted Touch-me-not D D X
Juncus effusus Smooth Rush D X
Justicia amen .cana Water Willow X D
Laportea canadensis Canada Wood Nettle D X
Lemna minor Lesser Duckweed D
Ludwigia uruguayensis (L.
hexapetala) Uruguay Water Primrose x X D D
Microstegium vimineum Nepalese Browntop D D X
Oxalis violacea Violet Wood Sorrel D
Panicum stipitatum Stipitate Panic Grass D
Polygonum lapathifolium Willow-weed D
Polystichum acrostichoides Christmas Fern x X D
Pteridium aquilinum Bracken D
Salvia lyrata Lyre-leaf Sage X D
Saururus cernuus Lizard's Tail x X D
Schoenoplectus tabernaemontani Soft-stemmed bulrush x
Sisyrinchium angustifolium Blue-eyed-grass X X

D = dominant, X = common or frequent in occurrence.
31
Wetland and Riparian Habitat Assessment
reservoir, and appeared to dissipate in the delta area of High Rock between the I-85 bridge and the
Potts Creek area.
Plant species diversity was higher in this type of floodplain wetland, with black willow still abundant
in the tree canopy of low-lying areas, but also overcup oak, silver maple (Acer saccharinum), green
ash (Fraxinus pennsylvanica) and American sycamore (Platanus occidentalis), plus many upland
species on the levees (Table 8.1-2). Invasives were most abundant in this cover type, probably
because of the frequent disturbance. Shrubs included buttonbush (Cephalanthus occidentalis), silky
dogwood, and two invasive species, bush honeysuckle, and Chinese privet (Ligustrum sinense). The
herbaceous layer was highly variable depending on level of disturbance and moisture regime. The
nettles (Laportea canadensis and Boehmeria cylindrica), Virginia wild rye (Elymus virginicus),
touch-me-nots (Impatiens capensis and I. pallida), and the invasive gill-over-the-ground and
Nepalese browntop all dominated in many examples of this cover type, along with many other species
(Appendix A). Vines were also an important structural component of many floodplain wetlands,
including several grapes (Vitis rotundifolia and V. vulpina), poison ivy and Virginia creeper
(Parthenocissus quinquefolia ).
8.1.3 Scrub-Shrub Wetland
Scrub-shrub wetland occurred throughout the reservoir system, with the exception of Falls. They
were most abundant on High Rock delta area, where they colonized slightly deeper sediment deposits
than the forested floodplain wetlands (Figure 8.1-2; Table 8.1-1). In these areas, young black willow
formed large stands of scrub-shrub wetlands immediately downstream of the forested wetlands, and
unless a large flood event scours out the sediment, these shrub wetlands will quite rapidly evolve to
forest. Very few other species occurred with the black willow, just the occasional buttonbush and
sycamore.
Black willow, buttonbush and silky dogwood (Corpus amomum) dominated the remaining smaller
scrub-shrub wetlands around the reservoirs. Most occurred in similar conditions as found in the
larger delta wetlands primarily on sediment bars and shallow substrates associated with tributary
mouths. Larger streams such as Abbotts Creek and Cranes Creek had more scrub-shrub wetland than
the smaller tributaries, presumably due to the higher sediment loads, deposition and scour associated
with the larger streams.
This wetland type is very dynamic due to the nature of its substrate source and type. Between high
flood events which can scour out sediment and the associated vegetation, and drought (or prolonged
drawdown) which can allow the vegetation to expand and solidify its grip on the substrate, scrub-
shrub wetlands can shift, grow or shrink on an annual basis. Examples include the drought period
which ended and was most pronounced in 2002, during which scrub-shrub wetlands on High Rock
expanded on the substrates exposed by the low water levels. Many one-to-five-year old seedlings
were observed in the 2003 field work at lower elevations than the adjoining forested and shrub
wetlands. The combination of two years of above-average water levels and flood events in 2003 and
2004 greatly reduced the extent and survival of these young seedlings, as observed in 2004 field
work. (Section 8.1.4)
8.1.4 Sparse Scrub-Shrub Wetland
This cover type was developed to describe the more tenuous of the scrub-shrub communities
described above. In the aerial photographs, extensive beds of scattered woody seedlings occurred on
32
Wetland and Riparian Habitat Assessment
sediment deposits approximately 2-3 feet below the full pool line on High Rock reservoir. Ground
truthing in the fall of 2003 confirmed colonies of widely-spaced black willow seedlings. Additional
ground truthing in 2004 found that many of these seedlings had died, presumably due to the near-full
pond conditions that occurred at High Rock for two successive years. While black willow is tolerant
of a wide variety of hydrologic conditions, including drought and flooding, it is intolerant for long
periods of either. Because of this highly dynamic response, the sparse scrub-shrub wetland beds
delineated on the cover type maps were modified in the field to better reflect 2004 conditions, on the
assumption that seedlings which survived through 2004 were likely to persist in the future. With
additional sediment trapping, these sparse scrub-shrub wetlands will quickly evolve into typical
scrub-shrub wetlands, and when adequate height is attained, into forested floodplain wetland. Even
when reduced during the 2004 ground truthing, this cover type remained the second most abundant
wetland cover type in High Rock (Table 8.1-1).
8.1.5 Emergent Wetland
The distribution of emergent wetlands was defined by the slope and substrates of the littoral zones,
and water level fluctuations of the reservoirs. On High Rock, emergent wetlands were very limited,
composing only 0.3% of all wetlands (Table 8.1-1). Those that occurred were confined to a narrow
zone near the full pond line, with the exception of the invasive Uruguay water primrose (Ludwigia
uruguayensis) on Abbotts Creek (Figure 8.1-2). The large drawdown that occurs in most years is
very likely the primary cause for the paucity of emergent marshes. Although 2004 had above average
water levels and High Rock was within several feet of full pond during every field trip, no emergent
marsh vegetation was observed more than 2-3 feet below the full pond line. Both Narrows and
Tuckertown had much more extensive emergent marsh development than High Rock (Figures 8.1-4
and 5; Table 8.1-1). On Tuckertown, which has a relatively stable water level regime, emergent
marshes were much more extensive along the shoreline, but remained confined within the top several
feet of the lake bed. This relatively narrow zone was probably the result of stable water levels
throughout most growing seasons. On Narrows, which typically experiences a moderate drawdown
with considerable weekly variability, the emergent marsh extends 1 -2 feet deeper into the lake than
High Rock and Tuckertown. These plants are most likely taking advantage of the additional growing
space available for portions of the growing season, created by modest, short-term drawdowns. At full
pond, the deeper plants are stressed, and at drawdown the higher plants are sustained by occasional
wetting as the reservoir refills periodically. Because the emergent wetlands on Narrows are most
prevalent on gradual shorelines, it is likely that groundwater is also an important component in
maintaining dewatered emergents. On Falls, which experiences frequent minor drawdown, the
emergent wetlands are limited by both the high water and the steep rocky shoreline. This reservoir
had the lowest acreage of wetlands of the four reservoirs, although emergents formed the greatest
percentage cover in this upland-dominated system.
The upland extent of the emergent marsh was limited typically by either a shoreline structure
(retaining wall, riprap) or a natural bluff along the shore at the full pond line. In areas where the
shoreline was gradual, the emergent marsh would frequently grade into a scrub-shrub wetland, or a
forested wetland under which light limitation halted the dominance by emergent species.
In High Rock, the few emergent marshes that occurred were dominated by water willow or, in one
case on Abbotts Creek, the invasive Uruguay water primrose. On Narrows and Falls, the emergent
marshes were almost exclusively dominated by water willow, often with smaller components of
lizards tail (Saururus cernuus) and swamp rose mallow (Hibiscus moscheutos). Emergent marshes
33
Wetland and Riparian Habitat Assessment
were most diverse in Tuckertown, often forming broad bands with well defined zonation of plant
species. While water willow continued to be a dominant component, other common species included
lizards tail, pickerel weed (Pontedaria cordata), swamp rose mallow, soft rush (Juncus effusus), soft-
stemmed bulrush (Schoenoplectus tabernaemontani), and spike rushes (Eleocharis obtusa and E.
quadrangulata). In Ellis Creek cove, American lotus (Nelumbo lutea), an exotic species, formed two
dense beds.
8.1.6 Aquatic Bed
Aquatic beds occurred in two of the reservoirs, Tuckertown and Narrows (Figures 8.1-4 and 5; Table
8.1-1). In Tuckertown, the beds typically occurred adjacent to emergent beds in the quieter coves and
tributary arms. In Narrows, the beds were confined to the four backwater ponds created by the
railroad bed on the west side of the reservoir. At all sites, gradual slopes and fine substrates provided
a suitable habitat. The high nutrient levels in both reservoirs also enhance growth of aquatics
(Normandeau 2004c). The lowest depth to which aquatic beds occurred in both reservoirs was 5-6
feet below full pond, probably due to light limitation in the water column. Secchi depth
measurements are commonly used to assess the depth of the photic zone in lakes. Most submerged
aquatic vegetation can persist at approximately 2-3 times the Secchi depth. Secchi depths ranges
were 2.6 -5.9 feet in Tuckertown and 2.1-3.2 feet in Narrows. In Tuckertown, the relatively stable
water levels provide a well defined zone for aquatics to establish. In Narrows, the backwater ponds
are all connected to the main body of the reservoir and therefore draw down periodically. During
drawdown the aquatic beds are exposed to desiccation, and freezing in the winter. The persistence of
aquatic beds in the ponds suggests that effects of Narrows water level fluctuations are moderated by
some other hydrologic factor (e.g., abundant groundwater) in some areas. It is likely that these beds
decline during years of greater drawdown, and expand during periods of more frequent high water
levels, such as 2003 and 2004. At High Rock, the large annual drawdown greatly limits the
establishment and survival of aquatic beds. On Falls, the steep rocky slopes, rocky shoreline, strong
currents and frequent water level fluctuations combine to minimize the potential for aquatic beds.
On Tuckertown and Narrows, aquatic species varied with location. Tuckertown had extensive beds
of native elodea, primarily (Elodea canadensis), with common associates of coontail (Ceratophyllum
demersum) and spike rush (Eleocharis cfacicularis). Hydrilla (Hydrilla verticillata), apotentially
aggressive invasive, occurred near the River Road boat launch, but was not a dominant. In Narrows,
the backwater ponds supported some elodea, as well as slender naias (Naias gracillima), a stonewort
(Chara zeylanica) and leafy pondweed (Potamogeton fohosus).
8.1.7 Upland
With the exception of the Forested Upland, the Upland cover types received little scrutiny under the
assumption that the developed cover types provided minimal natural resource value. The following
descriptions provide composites of the various upland cover type categories.
Forest : Typical forest vegetation of the Project area conforms closely with the Dry-to-Mesic Oak-
Hickory Forest (Piedmont Subtype), described by Shafale (2003) as perhaps the most common forest
association in the Piedmont. The acidic soil promotes dominance by heath species in the shrub
understory, e.g. the blueberries Vaccinium arboreum, V. stamineum, and sourwood (Oxydendrum
arboreum). The tree canopy usually comprises white oak (Quercus alba) and northern red oak (Q.
rubra), and pignut hickory and mockernut hickory (Carya glabra and C. tomentosa (alba)). This
forest type represents conditions midway between relatively dry and moist extremes of upland
34
Wetland and Riparian Habitat Assessment
vegetation. It occupies mid-slope positions of an intermediate gradient, and seldom faces either full
south or north.
At the drier end of the upland hydrosequence, on ridge tops and south-facing slopes, southern red oak
(Q. falcata) replaces northern red oak, and black gum (Nyssa sylvatica) assumes more importance
among the usual hickories and heaths. On exceptionally dry sites, e.g. root-restricting soils that are
shallow to bedrock or constitute dense clay hardpan, blackjack oak (Q. marilandica), post oak (Q.
stellata) and short-leaf pine (Pious echinata) may predominate.
At the moist end of the upland hydrosequence, American beech (Fagus grandifolia) typically has a
place, often dominant, along with sugar maple (Acer saccharum var. saccharum and barbatum), tulip
tree (Liriodendron tulipifera) and water oak (Q. nigra). Such forest includes some alluvial
bottomland and other low landscape positions, reaching upgradient in ravines and on north-facing
slopes, with the addition notably of chestnut oak (Q. prinus (montana)), flowering dogwood (Corpus
Florida), loblolly pine (Pious taeda) and Virginia pine (P. virginiana). Herbaceous dominants include
arum-leaved heartleaf (Hexastylis arifolium) and Christmas fern (Polystichum acrostichoides). Soils
relatively rich in exchangeable bases and organic matter generally coincide with these low-lying
mesic forest types. Particularly rich sites may include hop hornbeam (Ostrya virginiana), red
mulberry (Mopus rubra), an occasional basswood (Tilia americana), maidenhair fern (Adiantum
pedatum), and an abundance of several Viburnum species. Not all mesic sites are necessarily rich,
however. Steep, north-facing bluffs often promote the dense growth of heath shrubs, e.g. mountain
laurel (Kalmia latifolia) and Vaccinium species under chestnut oak, American beech and white oak.
When the natural upland forest succession is set back by periodic disturbance, typically logging and
wildfire, the pines (loblolly, short-leaf and Virginia) are among the first forest trees to occupy the
early tree seedling and sapling growth. Although fire of natural origins is no longer to be expected in
a rapidly developing lakeshore environment like the Project area, logging will continue to favor the
fast-growing softwoods. Wherever forest tracts are left undisturbed, and slower-growing but longer-
lived tree species (notably several of the oaks) assume dominance on suitable sites, the overall
proportion of pine as a canopy component may decline.
Grassland: In the Piedmont, naturally occurring areas dominated by grasses (Family Poaceae) and
forbs (most other herbaceous species, with typically broader leaves) result primarily from forest
wildfire. Since wildfire is now suppressed in the Project area, this early-succession cover type occurs
primarily as a deliberate product of vegetation management, wherever woody plant growth has to be
routinely discouraged, i.e. most notably along electric power transmission lines (Normandeau 2004d).
Golf courses and the landscaping around large buildings often create a particularly refined kind of
grassland that deserves recognition as this cover type because of its great extent-a lawn on an
institutional scale.
Grassland-Shrubland: This cover type represents a slightly later stage in a plant community's
succession as it reverts to forest. Tree and shrub seedlings that germinated along with herbaceous
plants now begin to assert dominance as they rise to rival the height of the taller herbaceous plants
and spread progressively over the shorter ones. In the Yadkin Project Area, this cover type was used
only in areas where routine disturbance maintained this cover type for long periods of time, e.g, under
powerlines. A description of the typical Yadkin maintenence program and schedule is provided in the
Transmission Line and Project Facility Habitat Assessment (Normandeau 2004d).
35
Wetland and Riparian Habitat Assessment
Agriculture (cropland): This land receives periodic tilling and planting treatments. It often
comprises fields of soy, cotton and hay in the Project area and vicinity, typically in relatively low-
lying, level terrain.
Agriculture (pasture): This cover type represents areas that are subject to grazing by livestock.
Superficially, it resembles Agriculture cropland or Grassland, but the herbaceous plants comprise
many species and grow to irregular heights owing to preferential selection by the livestock, and the
terrain is often uneven, on poorer soil than that used for cultivation.
Residential. Around the reservoir shoreline, the residential pattern comprises chiefly individual
houses or trailers separated from one another by small patches of lawn and scattered trees or, at a
lower density, by the remnant natural forest. At extreme low density, where residential structures and
activities disrupt or fragment the tree canopy and shoreline vegetation only minimally, they were
included in the upland forest cover type.
Commercial. Included with this infrequent shoreline cover type is all commercial and industrial
activity. In the Project area, the principal manifestations of both commercial and industrial land use
are related to the generation, transmission and application of energy, including the dams. Other
examples of commercial activities within the Project Area included marinas, and selected boat
landings.
Mineral. Large expanses of unvegetated soil, usually the result of sand and gravel extraction and
stockpiling or recent land development, constitute most of this minor cover type. Also included are
extensive rocky outcrops and outcrop clusters, which often provide basking sites and safe
underground shelters of importance to lizards and snakes.
8.2 WATER WILLOW ON NARROWS
On Narrows, water willow tends to form a near monoculture within the persistent emergent
community. Table 8.2-1 includes a list of species occurring within emergent beds in Narrows. Every
bed was dominated by water willow, frequently with no other species present. Lizards tail (Saururus
cernuus) and marsh mallow (Hibiscus moscheutos) were common secondary herbaceous species
within the marsh, as was the shrub buttonbush (Cephalanthus occidentalis). All other species
occurred infrequently and in low densities. These results differ somewhat from those of Touchette et
al. (2001), in which pickerelweed (Pontederia cordata), marsh purslane (Ludwigia sp), nice cutgrass
(Leerzia oryzoides) and redroot cyperus (Cyperus erythrorhizos) were described as the dominants
along with water willow in the emergent marsh. These species were present in 2004, but in low
abundance. Part of the explanation for the discrepancy may lie in the variability inherent in emergent
fringing marshes, especially following the severe drought years of 2001 and 2002, and the wet year of
2004. It is also possible that lizards tail was misidentified as pickerelweed in the 2001 report, because
NAI observed lizards tail to be a common species throughout all four reservoirs and pickerelweed,
which is similar in appearance, was mostly confined to quiet coves in Tuckertown.
Approximately 178 acres of water willow were recorded on Narrows (Table 8.1-1). Almost half of
them (86 acres) occurred in beds large enough to be delineated from the aerial photographs. The
remainder (92 acres) resulted from estimates of small and/or narrow beds fringing the edge of the
reservoir. Some of these smaller beds were patches (probably temporary) colonizing pockets of
sediment along rocky shores. Many others were more continuous bands that were 5-15 feet wide,
partially hidden under the tree canopy. In total, 30% of the shoreline of Narrows was estimated to
36
Wetland and Riparian Habitat Assessment
Table 8.2-1. List of plant species observed in shallow marshes on Narrows Reservoir.
Species Common Name Frequency
Justicia americana Water willow Abundant
Saururus cernuus Lizards tail Common
Hibiscus moscheutos Swamp rose mallow Common
Ce halanthus occidentalis Buttonbush Uncommon
Leerzia oryzoides Rice cut grass Uncommon
Pontederia cordata Pickerelweed Rare
Ludwi is s Marsh purslane Rare
Cyperus erythrorhizos Red-root cyperus Rare
Sa ittaria latifolia Broad-leaved arrow-head Rare
Cuscuta s p. Dodder Rare
Rhexia sp. Meadow beauty Rare
Tradescantia sp. Spiderwort Rare
Pistia stratiotes Water lettuce Rare
Betula nigra River birch Rare
Pol onum la athifolium Willow weed Rare
Echinochloa crusgalli Barnyardgrass Rare
Glyceria sp Manna grass Rare
Panicum cf. sti itatum Panic grass Rare
Sacciolepis striatus American cupscale Rare
support water willow. This number is probably an underestimate because approximately 20% of the
shoreline was not included in the survey.
The structural characteristics of the water willow beds were quite uniform throughout the Narrows
reservoir. The width of the beds was determined by the slope of the shore and the corresponding
water depths. During the 3 days of the pier study, water levels in Narrows were between 507.7 and
508.2 feet elevation USGS (539.0 and 539.5 feet Yadkin datum), which is approximately 1.5 to 2 feet
below full pool. The maximum water depth in which water willow typically occurred was 3 feet (5
feet below full pool). In general, water willow was densest between approximately 1.5 and 2.5 feet
below full pool. Plant heights ranged between 2.5 and 3.0 feet in the densest part of the bed. Plants
became shorter towards the upland and were typically tallest in the deepest water (up to 4.5 feet).
The upland extent was typically limited by either a shoreline structure (retaining wall, riprap) or a
natural bluff along the shore at the full pond line. In a few locations, the shoreline was gradual
enough to allow a more diverse freshwater marsh community to develop. Dominant species included
lizards tail, soft rush (Juncus effusus), rice cut grass (Leerzia oryzoides), and shrubs such as
buttonbush. Here the water willow mixed with the other species in a relatively narrow zone before
quickly declining upgradient.
To evaluate pier effects on water willow, a total of 34 piers and their surrounds were studied (Figure
8.2-1 and Table 8.2-2). Fifteen were considered new piers (constructed after March 1997), and 16
were old piers (constructed before March 1997). Three additional new piers were visited because
they provided good examples of either extreme of water willow impacts. The table is sorted in
increasing order of percent cover by water willow within the study area for each pier (20 feet to either
37
Wetland and Riparian Habitat Assessment
Figure 8.2-1. Narrows Pier and Water Willow Study Area.
38
w
Table 8.2-2. Characteristics of water willow, piers and shorelines of ne w and old piers.
% Water
Sample Year Constructed % Water Willow Under
# 1 or Modified 2 Willow Pier Water Willow Impacts Shoreline Type Substrate Type Comments
1998 0 0 Clearing around ramp & on Retaining wall & Suitable Dense water willow on natural
both sides ramp with float substrates adj to lot
1975 0 0 Clearing, beach? Retaining wall, dock, Suitable fines Good stand on edge of property,
not sure on right none in front, attempting to expand
1983 0 0 Not sure if cleared or too deep Retaining wall, dock 2' below full pond, otherwise suitable
1984 0 0 Not sure if cleared or too deep Retaining wall, dock 2' below full pond, May be cleared originally &
gravelly silt over substrates too deep for
bedrock recolonization
1985 0 0 Clearing in front of ret wall Retaining wall, dock Not sampled but Water willow well established on
- natural on adj lot appear suitable natural side
1987 0 0 Clearing in front of ret wall Retaining wall, dock? Gravel over
bedrock, emersed
1995 2 5 Clearing, imported sand? Retaining wall, dock Suitable fines Remnant water willow under dock
w/ stairs, beach?
1965 20 0 Clearing on both sides, Natural gentle bank Suitable Dense water willow on natural
brought in sand w/ dock & jet ski substrates on both sides
ramp
1999 25 0 Clearing in front of riprap Riprap, dock, retain Not sampled but Newish dock with riprap, fine water
wall on adj prop appears suitable willow in front of adj retaining wall
1983 30 0 Clearing on east side, far west Retaining wall, dock, Suitable coarse Water willow bed confined by
unused boat ramp retaining wall
WW15 2000 34 0 Boat ramp, clearing on right 1' bluff, gravel strand Silt with gravel
side with retaining wall strand
WW13 2001 40 0 Right side cleared, stairs Retaining wall, stairs, Gravelly silt
1962 40 0 Clearing around dock & on Retain wall, dock, Suitable Mod water willow bed on right side
left side boat ramp & house behind dock & along wall
1968 40 0 Clearing, boat ramp Retain wall, dock, Suitable fines Narrow water willow bed on left of
wide boat ramp wall, stops abruptly at both ends
1985 40 2 Clearing & old ways onto Retaining wall, dock, Not sampled but Water willow well established on
boathouse old ways appears suitable either side of clearing, attempting to
recolonize
WW12 1991 42 0 Jet ski ramp, boat ramp, Retaining wall, 2.5', Rocky gravelly silt Considered new in field-did not
clearing right side cleared appear in 1997 photo and had new
appearance. APGI records indicate
no construction since 1991.
f(D
a?
Q
01
Q
(continued)
0
Table 82-2. (Continued)
% Water
Sample Year Constructed % Water Willow Under
# 1 or Modified 2 Willow Pier Water Willow Impacts Shoreline Type Substrate Type Comments
WW8 2003 45 0 Boat landings on both sides of Eroding bank, 1', Fibric muck to 4"+
Comm dock drfitwood at base
WW14 1998 47 0 Jet ski ramp, other disturbance 24" Retaining wall Silt
WWI 1998 50 0 Footiboat traffic Eroding bluff, T with Gravelly silt
bedrock
2003 50 5 Major impacts from New dock & rock Suitable mostly Viable water willow patch on both
construction & clearing? gabions coarse sides
WW4 1998 51 0 Boat & foot traffic Natural gentle bank Silt loam
WW2 2003 58 0 Clearing around dock, esp R Eroding bluff, 1-3' Gravelly & sandy
side silts
WW3 2000 67 13 Footiboat traffic on R side, 60' l'bluff Gravelly silt
"beach" cleared to R of study
area
WWII 2002 70 0 Stairs & path Eroding bluff, 25 Cobble, gravelly
silt
WW5 1998 74 0 2 dogs routinely swim from T bluff with 2' Gravelly silt
shore erosion
WW9 1999 74 0 Light impacts from canoe Low bank Gravelly silt
landing on L side,
1980 75 2 Clearing by dock Retaining wall, dock Suitable Water willow on both sides of dock,
w/ stairs narrowed by retaining wall
1992 80 75 Clearing for boat ramp and by Retaining wall, boat Suitable Good water willow beds on both
pier ramp sides, good ex of low impact dock
WW7 1998 87 0 None at dock, 25' beach Eroding bluff, 35 Silty clay
cleared further down
WW10 2002 87 13 None Eroding bluff, 2' Gravelly silt
WW6 2004 92 38 None Riprap on W, eroding Gravelly sandy silt
bluff on E
1976 100 75 None - dense bed on both sides Retaining wall, low Suitable Good narrow stand in front of ret
dock wall
1998 100 100 None - dense bed on both sides Natural bluff with old Suitable Excellent example of low impact
low dock dock
2003 100 100 Slight productivity reduction Natural eroding Gr silt New, high dock allows water willow
under dock forested bluff underneath
Average 47.6 12.5
f(D
a?
Q
01
Q
' Piers with "WW" designation were part of the new pier study.
2 Bolded dates are "new" piers that were constructed or modified after March 1997.
Wetland and Riparian Habitat Assessment
side of the pier plus the pier). On average, water willow cover was approximately 48% of the
potential suitable habitat available, ranging the full spectrum of extremes between 0% and 100%
cover. Within the new piers, the range was smaller, between 34% and 92% cover.
The amount of water willow under the piers was much lower than the total pier study area, with an
average of 13% (Table 8.2-2). Only 11 of the 34 piers had any water willow under them at all. In
some cases, available light may have been a limiting factor, but in many cases, the vegetation appears
to have been removed. Most of the piers with 0% cover under the pier had considerably less cover
within the entire study area. The maximum width of the piers studied was 10 feet, and many were 8
feet or less, therefore the maximum percentage of the water willow habitat within a pier study area
that could be occupied by the pier (and potentially be unavailable to water willow) was 20%. Light
impacts due to the pier on adjacent water willow could lower the productivity of the beds but not their
presence. Therefore, any additional loss in percent cover above 20% can be attributed to land use and
human activities. Observed shoreline management and other human activities included complete
vegetation removal or mowing, importing sand for beaches, foot traffic from the shore to deeper
water, small boat access, and j et ski and boat ramp traffic.
Of the 6 piers with no water willow within the study area, all had suitable substrates and presence of
water willow in adjacent undisturbed sites (Table 8.2-2). Two had water levels that may have been
too deep at the foot of their retaining walls to support water willow, but the remaining four had either
emersed shorelines or very shallow flooding, both of which fell within the typical hydrologic setting
for water willow. In these cases, it is apparent that disturbance and possibly clearing are a factor in
the lack of water willow. Eight piers had more than 75% cover by water willow. These eight
included both old and new piers, with a range of pier heights and widths. Most had some amount of
water willow under the pier, with the exception of one that was well shaded by trees. In this instance,
the combination of shade from both the forest canopy and the pier may have provided too little light
transmission to support water willow. Other factors such as fetch, substrate and age of pier or its
modification had little discernible effect on predicting the presence or absence of water willow.
Within many of the pier study areas, robust water willow beds ended abruptly at the edge of activity
areas such as boat ramps, property lines, jet ski ramps, and swimming areas (see examples in Figure
8.2-2a and 2b). In other locations, the demarcation was less clear, but human disturbance was evident
as trampling and drag marks from boats (Figure 8.2-3). In the first instance, clearing was typically
complete with no or few stems of water willow remaining. In the second case, broken stems and
remnant root material were evident. Conversely, several docks were encountered in which vigorous
water willow formed an unbroken band on both sides and underneath the docks (Figure 8.2-4). The
construction date for these piers ranged from 1976 to 2003, indicating that height and age of the pier
is of less influence on water willow than the management and activity level within the water willow
bed.
8.3 MAJOR WETLAND FUNCTIONS
While many wetland functions were discussed in the characterization of the cover types (Section 8. 1),
it is worthwhile to summarize them to describe the overall contributions of wetlands to the Yadkin
Project Area. No systematic wetlands functions and values assessment was applied in this study, but
most assessment methods look at a similar suite of functions: flood control, sediment trapping,
nutrient removal, fish and wildlife habitat, and social values. A summary of wetland functions based
on observation of relevant physical and biological features of the four reservoirs is discussed below.
41
Wetland and Riparian Habitat Assessment
Figure 8.2-2a. Example of a lot with an intact water willow bed on left side of dock and
clearing on right side.
Figure 8.2-2b. Example of clearing and sand imported within a water willow bed.
Figure 8.2-3. Example of trampling impacts in water willow bed.
42

Wetland and Riparian Habitat Assessment
Figure 8.2-4. Example of robust water willow beds co-existing with piers in Narrows Reservoir.
8.3.1 Flood Control
Wetlands have long been recognized for their ability to slow and retain flood waters, thereby reducing
downstream damage by flooding. This is especially true in large river systems like the Yadkin.
Evidence of overbank flooding along the riverine portions of the Yadkin River and South Yadkin
River indicated that floods regularly occur up to 10 feet above normal. The floodplain and levee
habitats observed in this area are a product of the floods, but are also very effective at storing
floodwaters, therefore moderating flood events. These habitats are less common on the reservoirs,
most having been submerged at the time of their creation. The steep rocky shores of many sections of
the reservoirs are ineffective for flood storage. Yadkin operates High Rock Reservoir as a storage
reservoir and therefore, to the extent possible, generally tries to "capture" high reservoir inflows.
However, its size relative to the Yadkin River watershed limits its storage capacity during large
floods.
8.3.2 Sediment Trapping
As has been discussed in the Sediment Fate and Transport draft report (Normandeau 2004b), a large
sediment load enters High Rock from the Yadkin River and its tributaries. Much of this sediment
settles out as it enters the quieter waters of the reservoir. Deposition is most visible in the delta area
forming at the upper end of High Rock Reservoir. While substantial deposition was also apparent in
the floodplain wetlands of the Upper Yadkin and along the reservoir shores, this deposition can only
occur during flood periods and is probably minor compared to the sediment deposition that occurs
within the reservoir itself in the course of a typical year
8.3.3 Nutrient Removal
Wetlands have long been known to provide nutrient removal, transformation and attenuation from
surface and groundwater. All of the Yadkin reservoirs are eutrophic, and have high nutrient levels in
the water column for many months (Normandeau 2004c). As with the sediments, most of the
nutrients come from the larger watershed, although the dense development around sections of the
shores of High Rock and Narrows also contributes locally. The wetlands within the full pond limits
of the reservoirs have the ability to remove a portion of the nutrients. This would include most of the
shrub swamps, emergent wetlands and aquatic beds, but the small percentage of these wetlands
43
Wetland and Riparian Habitat Assessment
relative to the volume of water and quantity of nutrients in the collective system limit their
effectiveness. The large deltaic wetlands at the top of High Rock provide the greatest potential for
nutrient removal, but those are effective only during the portions of the growing season when water
levels are within the root zone of the plants. Although the elevation of the sediment bars is not
known, it is likely that they are exposed, and therefore unavailable for nutrient removal, for the latter
half of the average growing season. Tuckertown and Narrows, though 6 and 3 times smaller than
High Rock, respectively, have more acreage of emergent marsh and aquatic bed. The overall acreage
of wetlands are lower in both Tuckertown and Narrows due to the extensive acres of floodplain forest
and shrub swamp in the upper end of High Rock Reservoir, but the potential for nutrient removal by
emergent marsh and aquatic beds is higher because they are inundated much longer than the shrub
wetlands. On Falls, the low percentage of wetlands and low residence time for the water limit the
ability of this reservoir to provide nutrient removal.
8.3.4 Fish Habitat
As has been noted in the fish habitat report (Normandeau 2004a), wetlands provide important fish
habitat as breeding for many species, nursery habitat for young, cover for small resident species, and
forage for larger fish. The structure of the cover appears to be more critical than the composition, as
many lakeshore owners recognize in their creation of artificial cover with docks, trees, tires and other
debris. However, a study of water willow and fish habitat (Touchette et al. 2001) identified 17
species that use emergent wetlands in the course of the year, more than any other shallow-water
habitat. While fisheries in all four reservoirs appear to be healthy, the wetland structure and
distribution of each reservoir surely affect the fish populations. On High Rock the low percentage of
in-pond wetlands can have adverse impacts for centrarchid spawning. This family of fish, which
includes large-mouth bass, black crappie and bluegills, require water levels in the late winter and
spring that provide access to vegetated shallows to spawn (Normandeau 2004a). If the wetlands are
only a small component of the available habitat or are unavailable due to low water, these fish
experience a lower breeding success, and a loss of nursery and forage habitat. In High Rock, the bulk
of the spawning habitat lies in the scrub-shrub wetlands in the delta area in the upper end of High
Rock Reservoir. While this wetland type is one of the largest cover types in High Rock, it is
concentrated in one area of the reservoir and the rest of the reservoir has relatively little in-pond
wetlands available. A broader distribution and wider variety of in-pond wetlands would likely
enhance the centrachid populations in High Rock. The other three reservoirs have more wetland
habitat and/or smaller drawdowns, therefore access to wetlands during the spawning season is less of
a limiting factor.
8.3.5 Wildlife Habitat
Wetlands function to provide breeding, feeding and shelter habitat for terrestrial wildlife species. In
the Yadkin Project area, the large expanses of undeveloped lands that remain on all four reservoirs
combine with the open water of the reservoirs themselves to provide habitat for a wide variety of
wildlife species. Incidental observations of all wildlife during field work yielded more than 81 bird,
15 reptile, 16 amphibian and 5 mammal species or sign (Appendix B). Many of these were wetland-
dependent, relying on wetlands for a critical part of their life cycle: wood ducks, herons, prothontary
warblers, many reptiles, all amphibians, and beaver. The distribution of wildlife reflected the
available habitats around the reservoirs, with herons and egrets, for example, being most prevalent on
Tuckertown and Narrows, which had the most extensive emergent wetlands. Even the narrow water
willow beds fringing much of Narrows frequently supported foraging herons and egrets, a brood of
44
Wetland and Riparian Habitat Assessment
waterfowl or molting adult ducks. Turtles were abundant in all the reservoirs, with the possible
exception of Falls, but were most commonly observed in the upper reaches of the tributaries and
coves, where quiet water and ample cover was available. On High Rock, for example, turtles were
plentiful on upper Flat Swamp Creek, the Eagle Point Preserve area, and similar areas, while being
noticeably fewer on the more developed sections.
The American bald eagle is a protected wildlife species, listed as Threatened by the State and by the
US Fish and Wildlife Service. This species regularly breeds on some or all of the reservoirs in any
given year, using the open water for foraging and the adjacent forested habitat for nesting and
roosting (Center for Conservation Biology, 2004). No other known rare, threatened or endangered
terrestrial wildlife species occurs in the area that could be considered reservoir-dependent
(Normandeau 2004e)
83.6 Social Values
Attributes of wetlands that pertain to human perceptions are considered social values, and include
aesthetics, cultural (historic), active recreation (hunting and fishing), passive recreation (hiking, bird
watching), and education. Almost all wetlands provide one or more of these functions, and on the
Yadkin Project, this holds particularly true. The heavy use of the reservoirs and the Yadkin River
demonstrates the recreational function of the open water of the reservoirs, and the wetlands contribute
to both the active and passive forms by providing habitat for waterfowl and fish. The aesthetic
component is somewhat more subjective. While most would agree that wetlands lend beauty to the
landscape, wetland vegetation is sometimes perceived as an obstruction to recreation and the view of
the water. The tendency for lakeshore owners to clear out woody and emergent vegetation in front of
their homes has greatly diminished wetlands in those areas, especially on Narrows where the potential
for wetland development remains high.
9.0 EFFECTS OF CURRENT PROJECT OPERATION
The effects of current operation of the four reservoirs on wetlands and riparian habitats fall into two
general categories: direct effects from reservoir management, and secondary effects from reservoir
development. The first category includes hydrologic conditions, such as water levels, sediment
deposition and water quality. The second category relates to development, primarily residential,
around the periphery of the reservoirs, and recreational use, primarily boating and fishing, on the
reservoirs.
9.1 HYDROLOGY
As discussed in Section 6.3, the four reservoirs have significantly different hydrologic regimes based
on their original design and Yadkin's current management strategy. High Rock is the primary
storage reservoir for the system, and fluctuates the most seasonally (average 13.5 feet), monthly
(average 4.38 ft) and weekly (average 1.62 feet). Narrows experiences less drawdown (average 4.09
feet) with lower monthly (average 1.5 feet) and weekly (average 0.59 feet) fluctuations than High
Rock. Tuckertown and particularly Falls are operated on a run-of-river basis, and as a result have
short-term fluctuations of 2.42 and 5.90 feet, respectively, with little discernible seasonal effect.
These varying hydrologic regimes, in combination with shoreline characteristics, affect the
development of plant communities around the four reservoirs. Wetlands bordering and within the full
pond limits of the reservoirs are most affected because they are so closely tied to hydrologic
45
Wetland and Riparian Habitat Assessment
conditions. The upland communities within the Project Area are affected less by reservoir-related
hydrology and more by soils, aspect, slope, and groundwater levels. At High Rock, two processes are
fundamental to wetland development: water level fluctuation and sedimentation. Water level
fluctuation impacts vary with location on High Rock. Because the reservoir is so large, with long
arms following the various major tributary valleys, the center of the reservoir has developed
conditions more similar to a lake, while the tributary arms retain more riverine characteristics.
The riverine condition is most pronounced along the Yadkin River and the South Yadkin Rivers
within the upper portion of High Rock Project boundary. These are the largest rivers contributing to
High Rock, and as such, flow slows gradually over several miles before entering the truly lacustrine
portion of the reservoir. The length and magnitude of the gradient varies with river conditions, being
most pronounced during periods of high flow. The well defined river bed continues southward until it
begins to widen south of the I-85 bridge. North of the I-85 bridge, scouring appears to be the primary
influence on the plant communities, with little in-river vegetation and well developed bordering
forested floodplains in low-lying areas. South of the bridge, a depositional environment prevails,
resulting in extensive sediment bars that are colonized with varying aged stands of black willow.
This area forms the largest complex of wetlands in High Rock. The black willow ranges from 40-foot
trees to young seedlings forming sparse scrub-shrub wetlands. Sediment carried in by the river is
steadily accreting in this area, with shallow bars extending below Potts Creek that, while extremely
dynamic, are continuing to expand. The black willow stands function to hasten sediment deposition
by further slowing flow of the Yadkin. These processes are visible at a smaller scale on all of the
tributaries to High Rock, with transition areas from riverine conditions to the reservoir, and sediment
bars at the tributary mouths. Forested floodplain wetlands border the tributary banks and black
willow trees and shrubs dominate the accreting sediment bars.
Reservoir water levels have relatively little influence on the riverine floodplain wetlands of the
Yadkin River and the South Yadkin River within the Project area. Instead, these areas are most
influenced by rivers flows. With the large volumes of floodwater that pass down both rivers in most
years, in-river vegetation is scoured away, and the floodplain forested wetlands are replenished and
maintained, probably producing conditions similar to those that existed prior to construction of High
Rock dam.
The remaining wetlands on High Rock are much smaller in extent and more varied in composition.
They have formed on low-lying lands adjacent to the edge of the reservoir, and thus are affected by a
combination of reservoir water levels, groundwater and local surface water flow (runoff and small
drainages). Reservoir water levels are most influential at full pond, when flooding or soil saturation
occurs. When reservoir water levels drop, the wetlands continue to receive water from the other
terrestrial sources, therefore the reservoirs contribute to less of the hydrologic budget of many of
these wetlands. This wetland type was universal around all four reservoirs.
Noticeably lacking on High Rock are emergent wetlands and aquatic beds, composing only 0.6% of
all wetlands. While many factors probably contribute to this paucity (high energy from currents and
wave action, and low light penetration), the large seasonal water level drawdown is the primary one.
Few native emergent or aquatic species can tolerate the combined effects of the extreme conditions
created in the drawdown zone: flooding for prolonged periods in the spring, followed by drought as
the water levels drop well below the rooting zone in the late summer and fall. Exposure to freezing
and desiccation in the winter further stresses any overwintering plant material. Annuals are the best
46
Wetland and Riparian Habitat Assessment
strategists for taking advantage of regeneration opportunities, as was observed during the extreme
drought of 2002, when entire sections of the drawdown zone were colonized in the late summer by a
grass or sedge. Although the species was not identified, the plants were surely annuals that seeded on
the newly exposed lower substrates. These plants were killed later that fall when water levels
recovered. In 2004, when water levels remained high for the entire growing season, the narrow
drawdown zone was largely bare where perennial species (water willow, pickerel weed, elodea)
would be expected.
The other extreme of wetland habitat development is illustrated by Tuckertown, where relatively
stable water levels, quiet water, and fine, gently sloping substrates combine to allow extensive and
diverse emergent wetland development. Located mostly along the arms of the flooded tributaries, the
emergent marshes exhibited well defined zonation of pickerel weed, water willow, and cattail within
the full pond limit, often grading to shrub swamp above full pond. Aquatic beds, primarily native
elodea, formed in deeper water. The depth to which aquatics extended (approximately 5-6 feet) was
probably governed by light limitation in the water column more than water level fluctuation.
The complexity of wetland development within Narrows reservoir fell between High Rock and
Tuckertown, with emergent wetlands being more extensive but lower in species diversity than on
Tuckertown. Water willow formed the vast majority of the emergent community, with other species
being low in number and distribution (see section 9.2). Aquatic beds were abundant in the four small
ponds west of the railroad bed on the west side of Narrows. These areas are connected to the main
body of the reservoir and therefore fluctuate with the reservoir (NAI 2004a), but the aquatics appear
able to persist in dry years and expand in wet years.
At Falls, the combination of frequent water level fluctuations, high flows and steep, rocky substrates
limit the in-pond wetland development. Water willow beds have developed in a few areas where
slopes, substrates and a lack of scour permit. Aquatic beds were completely absent and would
unlikely ever be prevalent due to the high flows and lack of fines in this reservoir.
9.2 WATER WILLOW IN NARROWS
The distribution of water willow in Narrows underscores the tolerant, persistent nature of this plant.
An early successional species, it is capable of exploiting a wide range of growing conditions,
including moderate fluctuations in water levels. In undeveloped areas, the distribution of water
willow appeared driven by a combination of substrate, light availability, shoreline slope, and
shoreline use. The most extensive water willow beds were those established on fine (sand or silt)
substrates, with high light availability, shallow sloping shores, water depths at full pond of less than 3
feet, and limited human activity within the bed. However, attesting to its highly tolerant nature, many
other, albeit smaller, beds occurred under less than ideal conditions, such as rocky substrates,
overhanging trees, and chronic or periodic stress from human activity. Exposure to wave action and
currents typically prevents growth of many emergent species, but appeared to be a relatively
unimportant factor on water willow at Narrows. For example, several shallow subsurface bars in
Heron Cove supported extensive water willow beds but were highly exposed to wind, waves and boat
wakes. These beds were well established and appeared on all of the vegetation maps cited above, and
therefore are clearly able to withstand exposure for long periods of time.
The 2004 pier study underscored the tolerance of this species. Unlike the Touchette et al. (2001)
study, the presence and density of water willow appeared to be more closely linked with land use than
47
Wetland and Riparian Habitat Assessment
the influence of the pier on light availability. In general, percent cover of water willow ranged from
34 to 92% cover at the new piers (Table 8.2-2). In preparation for the field work, height and width of
the piers were assumed to be significant factors in that lower, wider piers would reduce light
availability to vegetation underneath the pier. This assumption was partially borne out in the field, in
that the lower docks generally had less water willow. However, a stronger association between the
distribution of water willow and piers appeared to be land use and shoreline use levels. Deliberate
land clearing and incidental disturbance appeared to play a major role in limiting the distribution of
water willow in the immediate vicinity of development.
As discussed in the Fisheries section (8.3.4), water willow is important for fish habitat, providing
refuge and forage for minnows and the juveniles of many larger species. Touchette et al. (2001)
captured 17 species in minnow traps and seines within, and adjacent to, water willow beds, which
supported seven or more species than other shoreline types sampled. Fish species diversity and
abundance were higher in sheltered water willow beds compared to exposed beds, and fish tended to
use the beds more in the summer months. The Narrows hydrologic regime allows access to all or
portions of the water willow beds for much of the growing season. In wet years such as 2004, water
levels stay close to full pond for much of the growing season, allowing inundation of, and therefore
fish access to, most of the water willow beds. In an average year, water levels typically remain within
2 feet of full pond, and thus continue to inundate the lower portion of the water willow beds. If water
levels drop below approximately 5 feet in Narrows, most of the water willow observed in 2004 would
be unavailable to fish. Water willow appears to be a very adaptable species, however, and may
extend further down the littoral zone as the water level drops in dry years.
The loss of water willow due to development is potentially large. While this study did not attempt to
estimate the acreage of habitat lost, the findings indicate more than half (52%), of the water willow
associated with lake shore development is eliminated during and after construction. This estimate of
loss is very likely an underestimate because the study only looked at piers where some water willow
was evident nearby or on adjacent lots. Many piers were observed where all water willow appeared
to have been eliminated on consecutive lots, therefore were ineligible for this study. Had they been
included, the complete loss of water willow on these lots would have further raised the estimate of
impact.
9.3 DEVELOPMENT
Human impact on the reservoirs can be viewed from two perspectives: the larger picture is
watershed-wide, and includes the major impacts of sedimentation and eutrophication to the reservoirs,
described in NAI 2004b and NAI 2004c, respectively. These are of such magnitude and regional
significance as to be beyond the immediate influence of the Yadkin Project or its operation. More
local issues include the use of the reservoirs and development along the shorelines. As described in
the water willow discussion for Narrows (Section 9.2), human development around the reservoirs can
have a profound effect on existing wetlands. Direct human impacts observed during field studies
include physical development (piers, retaining walls, beaches), vegetation removal and disturbance,
wave scour from boats and jet skis, and land management adjacent to the reservoirs. In the 2004
study of Narrows, over half of the water willow beds growing in front of developed shorelines had
been intentionally cleared, or incidentally impacted through human related disturbance. It is likely
that plant species diversity in the remaining emergent marshes on Narrows is reduced by the impacts
of wakes from boats and jet skis. Water willow appears capable of withstanding wave impacts from
48
Wetland and Riparian Habitat Assessment
wakes and exposure as well as tolerating the drawdown. Species which are more prevalent on the
quieter coves of Tuckertown, such as pickerel weed, cattail, and soft-stemmed bulrush, may be more
vulnerable to wave action and less tolerant of a drawdown
The effects of recreational use and development around High Rock are similar to those on Narrows.
While the number of emergent beds on High Rock is currently low due in most part to the drawdown
the impacts from human use observed on Narrows apply to High Rock as well. This would result in
further inhibition of emergent wetland development. Boat wakes are likely an added aggravation to
woody or emergent seedlings attempting to establish or persist on marginal habitats, including both
naturally colonizing black willows and the on-going effort to re-establish buttonbush (Lexington
Dispatch, November 21, 2003).
10.0 EFFECTS OF ALTERED PROJECT OPERATION
As described in Section 5.5, one objective of this study was to evaluate the potential effect on
wetlands associated with alternative reservoir water level regimes, particularly at High Rock. While
the riparian floodplains on the Yadkin River mainstem and South Yadkin River would be little
affected by any changes in the current High Rock water level regime, the impacts to wetlands around
the reservoir itself are potentially great. The following discussions evaluate potential changes in
wetlands, and by necessity, make the assumption that no major changes in sediment transport and
water quality occur.
The predictions of change in High Rock wetland vegetation are based on professional judgment
derived from experience on other reservoirs and familiarity with local conditions. Vegetation
distributions in Tuckertown and Narrows reservoirs were part of the evaluation, as was experience on
other reservoirs. The time frame in which the change is considered could also have an impact on the
estimate of acreage. In the short term, a sudden change in hydrologic regime may produce an
immediate response in the vegetation that is not representative of the mature community, such as the
quick flush of shrub seedlings, grasses and sedges observed in High Rock following the 2002
drought, or the dieback of those same species the following year when more typical water levels
returned. Over the very long term, sediment accretion and changes in water quality could result in
unforeseen increases or declines in vegetation. The estimates provided here are based on the
anticipated response of the vegetation following stabilization after the initial disturbance from the
new hydrologic regime, and under a long-term average of climatic conditions. Due to the lack of
precision possible in such an assessment, the percent change in wetland acreage was rounded to the
nearest quarter (25%, 50%, 75% and 100% relative to existing conditions). Because of the different
responses anticipated for the woody wetlands dominating the sediment bars in Upper High Rock
(Delta Area) and the largely unvegetated portions of the lower reservoir (Main Body), the two areas
were analyzed separately (Figure 10-1). The more riverine section above the I-85 bridge was
assumed to remain relatively unchanged under any of the reservoir water level alternatives considered
and was, therefore, excluded from the analysis (Yadkin River). The acreages of change are intended
to be representational only to provide the reader an estimate of the relative degree and distribution of
change.
49
Wetland and Riparian Habitat Assessment
Legend
n 618' Contour
?I620' Contour
1622' Contour
0624' Contour
" Section Boundary
Wetland Cover Types
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High Rock
Figure 10-1. High Rock contour intervals from 624N - 618N and cover types, divided into hydrogeomorphic sections used in alternatives assessment.
50
Wetland and Riparian Habitat Assessment
.9L
Legend
618'C'ontaGr
62T Contour
fm1 ;.onk=Vr
I..'y'... ontJ4r
IWetand Cover Types
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Figure 10-1. (Continued). High Rock contour intervals from 624N - 618N and cover types, divided into hydrogeomorphic sections used in alternatives assessment.
51
Main Body of
. T
1N!-1- r%--§- a
Wetland and Riparian Habitat Assessment
10.1 HIGH ROCK ALTERNATIVE 1- NEAR-FULL YEAR ROUND
Maintaining the reservoir near-full (within 3 feet of full) year round would result in multiple changes
to the in-pond wetlands. In the delta area at the upper end of High Rock Reservoir, the extensive
black willow forested wetlands would likely decline. While this species can tolerate flooding for long
periods of time, it can not survive permanent inundation. In the short term, the sediment bars would
become more dynamic without the stabilizing effects of the black willow. Those that have elevations
within 2 or 3 feet of full pond would be periodically colonized with emergent marsh species that can
withstand high flows, possibly water willow. However, without woody vegetation, it is likely that
major flood events would periodically scour away the vegetation and portions of the sediment to
redeposit it further downstream. Over time, the elevation of some of the bars would likely accrete
sufficiently to allow black willow to recolonize at a higher elevation, and allow some form of the
current mid-stream woody wetlands to re-establish. Approximately 25% of the existing wetland acres
in each of the contour intervals in the delta area of High Rock were estimated to remain as vegetative
wetland under this alternative (Table 10-1), with the assumption that the remainder would be drowned
under the permanent high water.
Table 10-1. High Rock estimates of wetland (acres) for the upper 6 feet of lake bottom under
three hydrologic alternatives.
Location and Hydrologic
Alternative
624-622 Contour Interval (acres)
622-620 620-618
<618 Vegetation
Total % of
Existing Acres of
Change
Upper High Rock Delta (Total Acres)
Area of Contour Interval 416 201 243 714
(Wetland Acres)
Existing* 340 164 198 368 1070 100% 0
Full Pond** 85 41 50 92 268 25% -803
Extended*** 85 41 50 92 268 25% -803
Storage**** 340 164 198 368 1070 100% 0
Main body of High Rock (Total Acres)
Contour interval 1001 578 723 10056
(Wetland Acres)
Existing 543 0 0 0 543 100% 0
Full Pond 751 434 542 0 1727 318% 1184
Extended 501 289 0 0 790 145% 247
Storage 136 136 88 0 360 66% -183
Combined (Wetland Acres)
Existing 883 164 198 368 1613 100% 0
Full Pond 836 475 592 92 1994 124% 381
Extended 585 330 50 92 1057 66% -556
Storage 475 300 286 368 1430 890/0 -183
* Delta - uses mapped PF01 c, PSS, and PEM numbers, distributed proportionately across 624-618 contours Main body -
uses PFOlc, PSS & PEM acres in 624-622 contour only
**Delta -Uses 25% of existing, assuming rest drowns. Main body -assumes 75% of contour vegetated, rest unavailable
due to exposure, slope & substrate
* * * Delta - Uses same number as full pond, assuming flooded all growing season. Main body - uses 25% of 2 upper
contours, assuming rest would not persist thru drawdown; no vegetation below 620 because of drawdown
52
Wetland and Riparian Habitat Assessment
Around the periphery of High Rock, maintaining a full pond regime would allow more extensive
emergent and aquatic beds to develop. In areas of shallow substrates, species similar to those of
Tuckertown would likely establish: water willow, pickerelweed, cattail, and square-stem spike rush.
Aquatic beds may form immediately off-shore from the emergents, although light limitation in the
water column is likely to continue in High Rock. However, similar to the shrub wetlands in Upper
High Rock, the woody floodplain forests and shrub wetlands that are abundant at the upper ends of
the larger tributaries will be pushed back by the stable full pond level, and replaced by emergent
wetlands.
For the in-lake acreage estimate of near-full conditions in Table 10-1, 75% of the upper 6 feet of the
reservoir (75% of the total acreage in each 2' contour interval) were assumed to have the potential to
develop a combination of emergent wetland and aquatic bed. The remaining 25% of the littoral zone
would be unavailable due to exposure, slope and substrate. Below a depth of 6 ft (<618' contour), it
was assumed no wetlands would develop due to water depth and limited light penetration. These
numbers were derived in part from observations in Tuckertown. While lacking in bathymetry below
the top 2 feet, much of the Tuckertown shoreline in the tributary arms supported emergent wetlands
and aquatic beds, while the mainstem had less, due mostly to steeper sides and rocky substrate. In
High Rock, the slopes are frequently less steep, and have fine mineral substrates, but exposure to
fetch and boat wakes may limit in-lake wetland development.
These anticipated changes would probably enhance fish populations on High Rock by improving in-
lake wetlands for spawning, nursery and shelter habitat. The overall acreage of wetland is anticipated
to increase, as well as the distribution of wetlands, so that fish species would have access to more
extensive emergent and shrub wetlands around most of the periphery of the reservoir. An associated
wildlife habitat improvement would also occur, as is seen at Narrows Reservoir. These same
wetlands and aquatic beds have the potential to become an annoyance to boaters and lake shore
owners, as well as locations for invasives to establish, especially in the high-nutrient environment
now found at High Rock.
10.2 HIGH ROCK ALTERNATIVE 2 - EXTENDED NEAR-FULL SEASON
In this alternative, the extent of the drawdown would be similar to existing conditions, but the timing
of the draw would allow the reservoir to refill sooner and delay the start of the winter drawdown from
mid-September to November. This alternative would probably have a similar impact to the black
willow beds in the upper High Rock delta as Alternative 1, because the willow would theoretically be
inundated the entire growing season. The emergent beds would respond in an intermediate fashion
between existing conditions and full pond Alternative 2 would be beneficial to the establishment of
some emergent species, but not the full suite found in Tuckertown. Pickerelweed and cattail are
typically sensitive to winter drawdowns. Water willow would be the most likely species to expand,
because it appears to be most tolerant of some fluctuations in water levels and may tolerate the winter
drawdown better than other species. No increase in aquatic bed acreage would be anticipated,
because aquatics, as their name suggests, can not withstand extended periods of dewatering. The
resulting community would be most similar to that found in Narrows.
For estimating acreages in Upper High Rock, the same assumptions as for the near-full scenario were
applied to the extended near-full season alternative: approximately 25% of the existing delta
wetlands were estimated to remain, assuming that the remainder would be drowned under the
continuous high water through the growing season (Table 10-1). For the main body of the reservoir,
53
Wetland and Riparian Habitat Assessment
50% of the upper 4 feet of lake bottom (50% of the total acreage in the 624-622 and 622-620 contour
intervals) were assumed to have the potential to support emergent wetlands (Table 10-1). The lower
depths were assumed to remain unvegetated because the aquatics could not tolerate the winter
drawdown, and the low water clarity would probably limit water willow growth below 4 feet. The
50% estimate is higher than the 30% cover of emergents observed at Narrows in 2004, but is
reasonable due to the significantly less rocky, more gradual shoreline at High Rock compared to
many sections of Narrows.
Despite the loss of wetlands in the delta area, this alternative may have a beneficial impact for fish
and wildlife species due to the expansion of wetlands around the periphery of the reservoir. By
dispersing suitable habitat over a broader area, fish and wildlife would have a wider variety of habitat
conditions available and be subject to less concentrated predator pressure. The winter drawdown
may reduce the risk of aquatic invasives compared to the near-full alternative, because drawdown is a
control technique for a number of these species.
10.3 HIGH ROCK ALTERNATIVE 3 - ADDITIONAL USE OF STORAGE
This alternative considers drawing down the water 20 feet on average, on the same schedule as
existing conditions, but refilling to 5 feet below full pond. This would have substantial impacts to
both the black willow delta wetlands and the remnant in-pond wetlands currently persisting in High
Rock. The deeper drawdown is probably of little consequence, but not refilling to the current summer
levels, which are frequently within 2-3 feet of full, would result in less flooding of the wetlands. On
the delta, the current trend of black willow establishing as seedlings and ultimately growing to
forested wetland would accelerate. The lower water levels would allow black willow and other
species to establish and grow more rapidly, and expose more sand bar area for colonization. The
existing bars would be more stable, requiring an even larger flood to impact them, and the hastening
of woody growth would further deter erosion and increase deposition. Many of these species would
be adversely impacted, possibly killed, during wet years such as 2003 and 2004 which will inevitably
produce extended periods of full pond. The extent of emergent wetlands in the main body of the
reservoir would probably remain little changed, although their position might change as they followed
the water level down. Woody species would likely encroach on the available habitat created along
the shore by the lower drawdown. However, these scrub-shrub species would be subject to the same
high-water events as the delta areas, and many encroaching plants may periodically dieback.
The estimate of wetland in the delta area under the storage scenario was kept the same as the existing
acreage of floodplain forest, shrub swamp and emergent wetland (Table 10-1). Under the storage
scenario, however, the wetlands would be much more dynamic, expanding in dry years and being
pushed back during wet years.
To estimate acreage of lake bottom supporting wetland vegetation, 50% of the existing vegetation
was assumed to persist in the upper 4 feet of the reservoir (50% of existing wetland acreage in
contour intervals 624-622 and 622-620, distributed equally between both contour intervals), with the
rest periodically dying back during high water events (Table 10-1). Emergent wetland and shrub
swamp vegetation is expected to re-establish at the lower fill line (5 feet below full pond, 520-518
contour), therefore the existing amount of those cover types (88 acres) was included in the estimate
for this alternative. Woody species would also encroach on the available habitat created along the
shore by the lower drawdown. However, these scrub-shrub species would be subject to the same
high-water events as the delta areas, and most encroaching plants would periodically die back.
54
Wetland and Riparian Habitat Assessment
Functionally, this storage alternative would be the least beneficial of the three hydrologic alternatives
to fish and wildlife species. Not only would the net availability of habitat be reduced, the anticipated
instability and yearly variability of the wetlands would result in a decline in spawning and nursery
success. Invasive aquatic plant species may have an advantage in this alternative because they are
often able to tolerate variable hydrologic conditions better than native species.
10.4 TUCKERTOWN ALTERNATIVE - INCREASED SHORT TERM FLUCTUATIONS
There are no plans to make any changes to reservoir operations at Tuckertown. However, if changes
in Project operations resulted in short-term water level fluctuations of 3-5 feet at Tuckertown,
compared to the current 1-2 feet, it could have the effect of reducing the diversity and possibly the
extent of emergent wetlands and aquatic beds in Tuckertown. Species diversity would be expected to
decline because the zonation which currently exists within the emergent marsh would be disrupted.
The species more tolerant of water level fluctuation, i.e., water willow, would likely expand to the
detriment of the other species. Pickerelweed, for one, is relatively intolerant of frequent water level
fluctuations, and would likely decline. Aquatic beds could persist if drawdowns during the growing
season were brief enough to not dehydrate them completely and if drawdowns during the winter were
brief enough to avoid freezing and desiccation. Some reduction in the aquatic bed productivity and
possibly extent is to be expected, especially toward the upper limit of aquatic bed growth.'
10.5 NARROWS ALTERNATIVE - ADDITIONAL USE OF STORAGE
If Yadkin Project operations were altered in order to utilize the additional storage available at
Narrows, more frequent drawdowns of 5-15 feet would result (as compared to the existing
drawdown limit of about 6 feet). From a wetland perspective the primary concern with increasing the
magnitude, frequency or duration of drawdowns at Narrows Reservoir would be the effect on
emergent wetlands (predominantly water willow). As discussed previously, water willow is an early
successional emergent that appears to withstand some level of periodic drawdown. However,
increasing the drawdown at Narrows during the winter could have the effect of desiccating and
freezing water willow beds that are mostly inundated Lmder the current Project operation. This
species appears able to tolerate the frequent fluctuations of the growing season water level that
currently occurs on Narrows, so an increase in magnitude at that time of year may not be detrimental
as long as refill continues at a similar frequency as current operations. Additionally, the combined
effects of an increase in the frequency, duration or magnitude of water level fluctuation in the winter
and summer could exceed water willow tolerance, and result in a decline.
10.6 FALLS ALTERNATIVE
Because Falls is so small and has such limited storage, no changes in the operation of Falls reservoir
were evaluated and no changes in the plant community attributable to Project operations are
anticipated.
11.0 CONCLUSIONS AND RECOMMENDATIONS
The wetland cover types around the four reservoirs are generally similar in species composition and
structure, with the exception of the floodplain wetland forests lining the Yadkin and South Yadkin
Rivers at the upper end of High Rock Reservoir. The forces maintaining these floodplain forests are
primarily riverme, including regular flooding and scouring during periods of high precipitation and
runoff within the Yadkin River watershed. The wetlands on the reservoirs have adapted over time to
55
Wetland and Riparian Habitat Assessment
the hydrologic patterns of each reservoir, all of which are more lacustrine in nature than riverine, with
the possible exception of Falls. Among the four reservoirs, the distribution of wetland cover types is
varied. High Rock is dominated by forested floodplain wetlands, predominantly on the portions of
the tributary streams that are influenced by reservoir water levels, and the delta area, where the
Yadkin River deposits much of its sediment load as it enters the quieter waters of the reservoir.
Forested floodplain wetlands dominated by black willow have established on the sediment bars, and
function to stabilize the existing bars and trap additional sediment. Early scrub-shrub stages of black
willow growth on the newly forming bars provide important fish habitat. On Tuckertown Reservoir,
forested wetlands are the most abundant wetland cover type, occurring in scattered stands at the
mouths of most tributaries. Narrows has relatively few wetlands overall (approximately 11%), of
which the most abundant cover type is emergent, with almost all beds dominated by water willow.
Falls has the fewest wetlands both in acres and percent (2%). Its steep, rocky sides and riverine
nature preclude wetland formation adjacent to the reservoir, and in-pond wetlands are limited by the
frequent water level fluctuations, and associated scour and currents resulting from its run-of-river
mode of operation. Narrows and High Rock have the most human development. High Rock has over
three times as much area in development as Narrows. Although NAI's estimate of the percentage of
developed shoreline around High Rock is relatively low (20%), this number is misrepresentative
because it includes the mostly undeveloped shorelines of the Yadkin and South Yadkin Rivers.
Calculating the developed area for High Rock Reservoir only (below the I-85 bridge), the percentage
rises to 25%. This number is more similar to that of Narrows, where almost one-third (31%) of the
shoreline is developed.
Water willow is an important ecological feature on Narrows. Narrows is the only reservoir where
emergent wetlands and shoreline development are extensive. High Rock and Falls have little
emergent marsh development, and Tuckertown has little shoreline development. On Narrows, the
emergent wetlands line 30% of the shoreline, mostly in beds too narrow or small to be mapped from
aerial photographs. These beds, almost exclusively dominated by water willow, provide important
fish and wildlife habitat, functioning as spawning grounds, forage and resident fish habitat, and thus
providing forage for piscivorous wildlife, and cover for waterfowl. Shoreline development has
adversely affected water willow by clearing and disturbance. Of the water willow beds studied in the
vicinity of docks, more than half of the water willow no longer existed.
Key wetland functions provided by the wetlands surrounding the four Yadkin reservoirs include flood
control and fish habitat. Flood control is most prevalent on the floodplain forests of the Yadkin
River, the South Yadkin River, and the larger tributary streams, most of which drain into High Rock.
These wetlands act to store flood waters and delay drainage, thereby reducing the flood crest. Habitat
for fish spawning, nursery, and forage is provided by wetlands on all four of the reservoirs: mostly in
the scrub-shrub wetlands of the delta area on High Rock, and the emergent wetlands on Tuckertown,
Narrows and, to a limited extent, on Falls. This function is provided only when water levels are high
enough to inundate the wetlands, which is generally limited to the early part of the growing season in
High Rock, with the exception of wet years such as 2004, and sporadically all year in Narrows. On
Tuckertown and Falls, both of which have more frequent, smaller fluctuations than High Rock or
Narrows, the wetlands are available to fish for most of the year. Wildlife habitat is an important
function on High Rock, Tuckertown and Narrows, providing forage and shelter for a variety of
wetland-dependent terrestrial birds, reptiles, amphibians and mammals. On Falls this function is
limited by the small area of wetlands relative to the reservoir. Other wetland functions, including
sediment trapping, nutrient removal, and social value are limited by the small size of the wetlands
56
Wetland and Riparian Habitat Assessment
relative to the size of the Yadkin River watershed and the large concentrations of sediment and
nutrients entering the reservoir system from upstream. The wetlands are indirectly contributing to
social values through recreation (fishing, hunting, and bird watching) by fish and wildlife
enhancement. The aesthetic values of the wetlands appear to be appreciated from afar, but many
shoreline landowners choose to clear wetlands and other vegetation to provide better access and
views of the water.
The hydrologic regime of the reservoirs, as determined by current Project operations, is a major
determinant in the distribution and type of in-pond wetlands. The wetlands adjacent to the
reservoirs, but above the full pond elevation are typically less influenced by reservoir water levels
because these wetlands frequently receive hydrologic inputs from other sources, such as groundwater
and surface flows. On High Rock, the delta area is a result of sediment deposition occurring when
flow down the Yadkin River is slowed by the impoundment sufficiently to drop some of the fines
suspended in the water column. This delta area is vegetated by floodplain forested wetlands and
scrub-shrub wetlands, all dominated by black willow. It is probably the primary spawning ground for
many fish species in High Rock when inundated in the spring and early summer. The late summer
drawdown that is typical on High Rock allows the black willow to persist, but at the same time is
limiting to the development of more typical lake-shore emergent wetlands and aquatic beds. In
contrast, Tuckertown Reservoir has the most stable water regime of the four reservoirs, and also has
the most diverse emergent wetland development and aquatic beds. Narrows is intermediate in in-
pond wetland quality between High Rock and Tuckertown, with more extensive emergents than
Tuckertown, but less species diversity. The lower species diversity can probably be attributed to the
greater drawdowns experienced on Narrows, which water willow alone appears to tolerate.
Changes in Project operations could alter the hydrologic regimes and thus could have significant
impacts to the wetlands of the three largest reservoirs. This study evaluated the effects of three
alternative reservoir water level regimes on High Rock:
¦ Alternative 1 - "Near-Full Year Round" - a stable water level would result in the
development of emergent wetlands and aquatic beds along much of the shoreline of High
Rock, probably similar in zonation and species diversity to Tuckertown. A stable water level
is also likely to have the adverse impact of eliminating much of the black willow that has
colonized the delta area, particularly in the deeper areas. Emergents could colonize some of
the areas, but the area is likely to be less stable and more subject to shifting sediment during
large flood events. In general fish and wildlife habitat would be enhanced, although the risks
of colonization by invasive aquatics would also increase.
Alternative 2 - "Extended Near-Full Season" - a shorter winter drawdown would likely
enhance wetland development around the perimeter of High Rock, probably similar to
Narrows with water willow dominating the emergent wetlands. Water willow is able to
tolerate the fluctuating water levels on Narrows and may be able to persist in many areas
through a winter drawdown on High Rock. The black willow beds in the delta area may
decline somewhat, however they would probably persist given that periodic exposure during
portions of the growing season occurs now in most years and would likely continue under
Alternative 2. This occasional exposure and drainage would probably be sufficient to allow
the established black willow stands to persist. Fish habitat may be improved under this
57
Wetland and Riparian Habitat Assessment
alternative because of the wider distribution of wetlands around the periphery of the
reservoir.
Alternative 3 - "Additional Use of Storage" - this alternative would be most detrimental to
existing wetlands around High Rock. While the black willow stands on the delta area would
probably thrive and expand, many of the remnant in-pond wetlands around the periphery of
the reservoir would be less stable. The combination of a longer winter drawdown, a lower
average water level, and periodic full pond levels would create a very difficult environment
for emergent wetlands to persist or colonize. It is possible that woody species, primarily
black willow and button bush, would tolerate the extremes of conditions created by this
alternative and expand around the shoreline of the reservoir, but their potential to contribute
to fish habitat would be limited by the lower average full pond line. Also, the risks of
excessive flooding during wet years could result in considerable dieback of the encroaching
woody species. Fish habitat would decline under this alternative due to a combination of
less available wetland acreage and more seasonal and annual variability. Invasive aquatic
plants would potentially be able to out compete native aquatics in this more variable
environment.
At Tuckertown, increases in short-term water level fluctuations by several feet would likely reduce
the species diversity and alter the zonation of the emergent wetlands now prevalent on the reservoir.
Water willow would be likely to expand, because of its obvious tolerance of water level fluctuations
on Narrows. Aquatic beds could also decline if the fluctuations were prolonged enough for them to
dehydrate. Given that this reservoir has the highest quality in-pond wetlands of the four, based on
both species diversity and zonation, the alternative regime could be detrimental by degrading the
wetlands to the more monotypic vegetation found on Narrows.
At Narrows, utilization of more of the reservoir's storage capacity, which would result in a greater
winter drawdown and more routine and deeper draws in the summer, could have an adverse impact on
the water willow beds. While water willow is clearly tolerant of the current summer water level
fluctuations, the combination of a winter drawdown and greater summer fluctuations could exceed
this species tolerance and result in a decline. The abundance of fish and wildlife observed on
Narrows depends in large part due to the habitat provided by the water willow, and would likely
decline along with the loss of water willow.
12.0 REFERENCES CITED
APGL 2002. Yadkin Hydroelectric Project FERC No. 2197 NC Project Relicensing, Initial
Consultation Document, September, 2002. ALCOA Power Generating Inc, Yadkin Division,
Badin, NC
Baranski, M.J. 1993. Natural areas inventory for the Yadkin River corridor in Davie, Davidson, and
Rowan Counties, North Carolina. Conservation Trust for North Carolina, Raleigh, NC.
Baranski, M.J. 1994. Natural areas inventory for Rowan County, North Carolina. Conservation Trust
for North Carolina, Raleigh, NC.
Boaze, J.L. 1997. Badin Lake water willow mitigation evaluation. Fish & Wildlife Associates,
Whittier, NC
58
Wetland and Riparian Habitat Assessment
Center for Conservation Biology. 2004. An assessment of the bald eagle and great blue heron
breeding populations along High Rock, Tuckertown, Narrows and Falls Reservoirs in Central
North Carolina. Prepared for Yadkin, Inc., Badin, NC.
Cowardin, L.M., V.Carter, F.C. Golet, and E.T.LaRoe. 1979. Classification of wetlands and
deepwater habitats of the United States. U.S. Fish & Wildlife Service, FWS/OBS-79/31.
Environmental Laboratory. 1987. Corps of Engineers wetlands delineation manual. Tech.Rep. Y-
87. U.S.Army Engineers Waterways Experiment Station, Vicksburg, MS.
Federal Register, July 13, 1994, http://soils.usda.gov/use/hydnc/ntchs/tech notes/notel.html,
December 14, 2004
Goldsmith, R., D.J.Milton, and J. Wright Horton, Jr. 1988. Geologic map of the Charlotte 1 degree
X 2 degree quadrangle, North and South Carolina, Map I-1251-E, Miscellaneous
Investigations Series, United States Geological Service, Washington, DC.
J. Bean, Yadkin field staff, personal communication, 2004.
Normandeau. 2004a. High Rock Reservoir aquatic habitat study. November 2004, Prepared for
Alcoa, Yadkin Division, Badin, NC.
Normandeau. 2004b. Sediment Fate and Transport, Draft Study Report. Yadkin Project Relicensing,
December, 2004. Prepared for Alcoa, Yadkin Division, Badin, NC.
Normandeau. 2004c. Yadkin Hydroelectric Project, FERC No. 2197 NC, Water Quality, Draft Study
Report. December, 2004. Prepared for Alcoa, Yadkin Division, Badin, NC.
Normandeau. 2004d. Transmission Line and Project Facility Habitat Assessment. Draft report.
Yadkin Project Relicensing, December, 2004. Prepared for Alcoa, Yadkin Division, Badin,
NC.
Normandeau. 2004e. Rare, Threatened and Endangered (RTE) Species Survey Report. Draft report.
Yadkin Project Relicensing, December, 2004. Prepared for Alcoa, Yadkin Division, Badin,
NC.
R.A. Johnson. 2004. Yadkin field staff, personal communication.
Schafale, M.P. 2003. Piedmont Guide The Carolina vegetation survey. www.bio.unc.edu/faculty/
peet/lab/cvs/pubs/piedmont.gd.doc. Draft update to Schafale, M.P. 2000. Classification of
the natural communites of North Carolina: Fourth approximation. NC Natural Heritage
Program, Dept. of Environmental and Natural Resources, Raleigh, NC.
Sharp, Shannan. 2004. Personal communication. US Forest Service, Uwharrie National Forest.
Touchette, B.W., J.M Burkholder, and H.B.Glascow. 2001. Distribution of water willow (Justicia
Americana L.) in the Narrows Reservoir. Center for Applied Aquatic Ecology, North
Carolina State University. Raleigh
USDA Forest Service. 1994 (July). Ecological subregions of the United States: section descriptions.
Report WO-WSA-S, USDA Forest Service, Washington, DC.
USFW. 1986. Land and Resource Management Plan, 1986-2000, Croatan and Uwharrie National
Forests. Forest Service, Southern Region, US Department of Agriculture, Asheville, NC.
Yadkin, Inc. 1999. Yadkin Project Shoreline Management Plan. Vol. 1, FERC Project No. 2197,
ALCOA, Yadkin Division, Badin, NC.
59
Wetland and Riparian Habitat Assessment
APPENDIX A
Plant Species Observed in Cover Types
Throughout the Yadkin Project Area
Wetland and Riparian Habitat Assessment
H abita t Type
w w3 3 3 w
Species Common Name PF01 PFOlc PSSl PSSp PEM AB UPL
TREES
Acer saccharum barbatum x
Acer saccharum leucoderme Chalk Sugar Maple X
Aesculus sylvatica Painted Buckeye x X
Ailanthus altissima Tree of Heaven X
Albizia julibrissin Mimosa
Betula nigra River Birch x X X X X
Carpinus carohniana American Hornbeam x X X
Carya carolinae-septentrionalis x
Carya cordiformis BitternutHickory x X
Carya glabra Pignut Hickory X
Carya ovata x
Carya sp. Hickory species x
Carya tomentosa MockernutHickory X
Castanea dentata x
Celtis laevigata x X
Cercis canadensis x X
Chionanthus virginicus x X
Cornus jlorida Flowering Dogwood x X X
Diospyros virginiana x
Fagus grandifolia x X X
Fraxinus amencana x X
Fraxinus pennsylvanica Green Ash x X X X
Fraxinus spp. Ash species x X X
Ilex opaca x X X
Ilex sp. X
Juglans nigra x
Juniperus virginiana x X
Liquidambar styracijlua Sweet Gum x X X X
Liriodendron tulipifera Tulip Tree x X X
Nyssa sylvatica Black Gum x X
Ostrya virginiana x X
Oxydendron arboreum Sourwood x X
Paulownia tomentosa x
Pinus echinata Short -leaf Pine X
Pinus sp. Pine species x
Pinus taeda Loblolly Pine X
Pinus virginiana Virginia Pine x X
Platanus occidentalis American Sycamore x X X
Populus alba x
Populus deltoides Cottonwood x X X X
Prunus serotina Black Cherry X
Prunus sp. Cherry species x
Quercus alba White Oak x X X
Quercus coccinea x X
Wetland and Riparian Habitat Assessment
H abita t Type
w w3 3 3 w
Species Common Name PF01 PFOlc PSS1 PSSp PEM AB UPL
Quercus falcata Southern Red Oak x X X
Quercus lyrata Overcup Oak x X X
Quercus marilandica x X
Quercus nigra x X
Quercus phellos Willow Oak x X X
Quercusprinus (Q. montana) Chestnut Oak x X
Quercus rubra x X X
Quercus spp. Oak species x X X
Quercus stellata x
Quercus velutina x
Robinia pseudo-acacia X
Salix nigra Black Willow x X X X X X
Salix sp. Willow species x X X
Sassafras albidum x
Taxodium distichum x X X
Ulmus alata Winged Elm x X X
Ulmus americana x X X
Ulmus rubra x
Ulm us sp. X

SHRUBS
Alnus serrulata x X X X
Amelanchier arborea x
Amelanchier sp. X
Amorpha fruticosa X
Amorpha schwerinii Piedmont Indigo-bush x
Amorpha sp. X
Calycanthus florzdus X
Ceanothus amen .canus x
Cephalanthus occidentalis Buttonbush x X X X X
Cornus amomum Silky Dogwood x X X X
Crataegus uniora x
Euonymus amen .cana x
Gaylussacia frondosa X
Hamamelis virginiana x
Hypericum sp. X X
Ilex decidua x X
Ilex laevigata
Itea virgin ica x X
Kalmia latifolia x X
Leucothoe racemosa x
Ligustrum japonicum Japanese Privet
Ligustrum sinense Chinese Privet x X
Lindera benzoin x
Lonicera X
Lonicera sp. X
Wetland and Riparian Habitat Assessment
H abita t Type
w w3 3 3 w
Species Common Name PF01 PFOlc PSS1 PSSp PEM AB UPL
Lonicera x Bella Bush Honeysuckle X X
Magnolia acuminata X
Rhododendron arborescens X
Rhododendron maximum X
Rhododendron nudiflorum X X
Rhus aromatica X
Rosa multiflora Multiflora Rose X
Rosa palustris X
Rosa wichuraiana Memorial Rose X
Rubus argutus Blackberry
Sambucus canadensis X X
Staphylea trifolia X X
Styrax grandifolia X
Symplocos tinctoria X
Vaccinium arboreum Farkleberry X
Vaccinium sp. X
Vaccinium stamineum Deerberry X
Viburnum acerifolium X
Viburnum dentatum X X X
Viburnum prunifolium X
Viburnum rufidulum X

HERBS
Actaea sp. X
Agave (Manfreda) virginica X
Agrostis sp. X
Allium sp. X
Amphicarpa bracteata X
Amsonia tabernaemontana X
Andropogon virginicus (A. glomeratus) X X
Aneilema keisak MarshDewflower X
Antennaria plantaginifolia X
Anthoxanthum odoratum Sweet Vernal Grass
Apios americana X
Arisaema cf triphyllum Swamp Jack-in-the-Pulpit X X X
Arundinaria gigantea Cane X X
Asarum canadense X
Asclepias tuberosa X
Asplenium platyneuron Ebony Spleenwort X
Aster X X
Aster cf. lateriflorus Calico Aster X X X
Aster cf. vimineus Small White Aster X X
Aster linariifolius X
Aster sp. X X
Aureolaria pectinata X
Aureolaria sp. X
Wetland and Riparian Habitat Assessment
H abita t Type
w w3 3 3 w
Species Common Name PF01 PFOlc PSS1 PSSp PEM AB UPL
Aureolaria virginica x
Azolla caroliniana x X
Bambusaceae A bamboo x
Baptisia alba Thick-pod White Wild
Indigo X
Bidens arzstosa x
Bidens discoidea x
Bidens frondosa Devil's Beggar-ticks X
Boehmeria cylindrica Small-spike False Nettle X
Boltonia caroliniana x
Botrychium sp. Grape Fern species x
Campsis radicans Trumpet Creeper x X X
Cardamine concatenata x
Carex alata x
Carex baileyi x X
Carex comosa x X
Carex crinita Fringed Sedge x X
Carex folliculata X
Carex lupulina Hop Sedge x X X
Carex lunda x
Carex muhlenbergii x
Carex pensylvanica Pennsylvania Sedge X
Carex rosea x
Carex scoparia x
Carex sp. X X X
Carex tribuloides Blunt Broom Sedge x X X
Carex typhina x X X
Cf. Veronica sp. X
Chasmanthium latifolium x X X
Chenopodium sp. X
Chimaphila maculata Spotted Wintergreen x X
Chrysogonum virginianum x
Cirsium carolinianum Carolina Thistle X
Clitoria mariana x
Comandra umbellata x
Commelina sp. X X
Commelina virginica x X
Coreopsis auriculata x X
Coreopsis major x
Coreopsis sp. X X
Coreopsis ver2icillata Verticillate Tickseed X
Cunda oreganoides x
Cuscuta sp. X X X
Cyperus lancastriensis x
Cyperus ovularzs x
Cyperus sp. X
Wetland and Riparian Habitat Assessment
H abita t Type
w w3 3 3 w
Species Common Name PF01 PFOlc PSS1 PSSp PEM AB UPL
Cyperus strigosus x
Dichanthelium sp. X
Dioscorea batatas x
Diospyros virginiana x
Dulichium arundinaceum x
Echinochloa crus-galli x
Eclipta alba x
Eleocharis obtusa Blunt Spikerush X
Eleocharis quadrangulata x X
Eleocharis sp. X
Elephantopus sp. X
Elymus virginicus Virginia Wild Rye x X X
Epifagus virginiana x
Epigaea repens x
Erzanthus brevibarbis x X X
Erzgeron cf philadelphicus x
Erythronium amerzcanum x
Eupatorium capillifolium
Eupatorium fistulosum X
Eupatorium rotundifolium x
Eupatorium rugosum White Snakeroot x X X
Eupatorium serotinum
Eupatorium sp. X
Euphorbia cf corollata x
Galax aphylla x
Gelsemium sempervirens x X
Gentiana sp. X
Geranium maculatum x X
Geum X
Glechoma hederacea Gill-over-the-ground x X
Glycena X
Glycerza strzata x X X
Gnaphalium cf obtusifolium
Goodyera pubescens X
Helianthus X
Helianthus cf laevigatus Smooth Sunflower X
Helianthus cf tuberosus x
Helianthus divaricatus x
Hepatica amerzcana x X
Heterotheca (Pityopsis) graminifolia Grass-leaved Golden-aster X
Hexastylis arifolium Arum-leaved Heartleaf X
Hibiscus militarzs x
Hibiscus moscheutos Swamp Rosemallow x X X
Hieracium sp. X
Hieracium venosum Veined Hawkweed X
Houstonia caerulea Bluets x X
Wetland and Riparian Habitat Assessment
H abita t Type
w w3 3 3 w
Species Common Name PF01 PFOlc PSS1 PSSp PEM AB UPL
Houstonia purpurea X
Houstonia sp. X
Hypericum prolificum x
Hypericum punctatum
Hystrix patula x X
Impatiens capensis Spotted Touch-me-not x X X
Impatiens pallida x
Iris cristata x X
Iris pseudacorus x
Iris sp. X
Juncus alata x
Juncus diffussimus x
Juncus effusus Smooth Rush x X
Juncus spp. X
Justicia amen .cana Water Willow x X
Lactuca sp. X
Laportea canadensis Canada Wood Nettle x X
Lathyrus venosus x
Leersia oryzoides x
Lemna minor Lesser Duckweed X
Lemna perpusilla x
Lemna sp. X
Lespedeza cuneata Chinese Lespedeza
Lespedeza sp. X
Ligusticum canadense x
Lilium michauxii x
Lindernia dubia x
Lobelia sp. X
Ludwigia alternifolia x
Ludwigia cf. glandulosa x
Ludwigia decurrens x
Ludwigia peploides x
Ludwigia sp. X X
Ludwigia uruguayensis (L. hexapetala) Uruguay Water Primrose x X X X
Lycopus sp. X X
Lysimachia nummularia x X
Lysimachia quadrifolia
Mecardonia acuminata x
Melica mutica x
Menispermum canadense x
Microstegium vimineum Nepalese Browntop x X X
Mimulus ringens x
Muhlenbergia x
Nelumbo lutea x X
Oxalis violacea Violet Wood Sorrel X
Panicum cf. clandestinum x
Wetland and Riparian Habitat Assessment
H abita t Type
w w3 3 3 w
Species Common Name PF01 PFOlc PSS1 PSSp PEM AB UPL
Panicum sp. X X X X
Panicum stipitatum Stipitate Panic Grass X
Parthenium integrifolium x
Pehandra virginica x X
Penstemon laevigatus x
Phlox sp. X
Phryma leptostachya x
Phytolacca amencana x
Pilea pumila x X
Pistia stratiotes x X
Plantago spp. X
Pluchea camphorata x
Poaceae X
Podophyllum pehatum x X X
Polygala cur2isii
Polygonatum biflorum x
Polygonum hydropiperoides x
Polygonum lapathifolium Willow-weed X
Polygonum punctatum x X
Polygonum sagittatum x
Polygonum scandens x
Polygonum setaceum x X X
Polygonum spp. X X X
Polypodium polypodioides x X
Polypodium sp. X
Polystichum acrostichoides Christmas Fern x X X
Polyttichum sp. A haircap moss x
Pontederza cordata x
Porteranthus stipulatus Indian Physic X
Prenanthes sp. X
Pterzdium aquilinum Bracken X
Ptiliminium capillaceum x
Pycnanthemum incanum x
Pycnanthemum tenuifolium x
Ranunculus sp. X X
Rhexia sp. X X
Rhyncospora cf glomerata x
Rhyncospora corniculata x
Rorippa islandica x
Rudbeckia triloba x
Ruellia carolinensis x X
Ruellia virginica x
Rumex acetosella
Rumex sp. X X X
Rumex ver2icillata x X X
Sacciolepis striata American Cupscale x
Wetland and Riparian Habitat Assessment
H abita t Type
w w3 3 3 w
Species Common Name PF01 PFOlc PSS1 PSSp PEM AB UPL
Sagittaria X
Sagittana latifolia x
Salvia lyrata Lyre-leaf Sage X
Sanicula cf canadensis x
Saururus cernuus Lizard's Tail x X X
Saxifragus michauxii x
Scirpus cyperinus x
Scirpus sp. X X
Scirpus validus (Schoenoplectus tabernaemontani) X
Scutellaria integrifolia x
Sedum sp. X
Sedum ternatum x
Selagmella rupestris x
Setaria sp. X
Silphium compositum
Sisyrinchium angustifolium Blue-eyed-grass x X
Smilacina (Maianthemum) racemosa x
Smilax sp. X X
Solidago caesia x
Solidago odora
Solidago plumosa Yadkin River Goldenrod X
Solidago sp. Goldenrod species x
Sparganium americanum x X
Spirodela polyrhiza X
Stellaria pubera X
Stipa avenacea x
Tephrosia cf virginiana
Thalictrum (Anemonella) thalictroides x
Thalictrum revolutum x X
Thalictrum sp. X
Thelypteris simulata x
Tiarella cordifolia x X
Tovara virginiana x
Tradescantia x X
Tradescantia ohiensis x
Trillium catesbaei x
Tnpsacum dactyloides x
Typha latifolia x
Uvularia sessifolia x X
Verbena alternifolia x
Verbena urticifolia x
Vernoma acaulis x
Viola sp. X X
Woodsia obtusa x
Zephyranthes atamasco x X
Zizia aptera x
Wetland and Riparian Habitat Assessment
H abita t Type
w w3 3 3 w
Species Common Name PF01 PFOlc PSS1 PSSp PEM AB UPL
Zizia aurea X

LIANAS
Clematis viorna X
Cocculus carolinus X
Dioscorea villosa X X
Euonymus sp. X X
Gelsemium sempervirens Yellow Jessamine X X
Hedera helix English Ivy
Lonicera flava X
Lonicera japonica Japanese Honeysuckle X X X
Lonicera sempervirens X
Lonicera sp. Honeysuckle species X
Parthenocissus quinquefolia Virginia Creeper X X X
Pueraria lobata Kudzu X
Rhus radicans Poison Ivy X X X
Rosa sp. X
Similax bona-nox Saw greenbrier X
Similax hispida Bristly greenbrier X
Smilax rotundifolia X
Smilax sp. Greenbrier species X X X
Vitis rotundifolia X
VMS SP. Grape species X X X
Vitis vulpine Frost grape X
Wisteria sp. X

SUBMERGED AQUATIC VEGETATION
Algal scum X
Ceratophyllum demersum X
Chara zeylanica sejuncta X
Eleocharis cf acicularis X
Elodea canadensis X
Elodea nuttallii X
Hydrilla verticillata Hydrilla X
Naias gracillima X
Potamogeton foliosus X
Wetland and Riparian Habitat Assessment
APPENDIX B
Incidental Observations of Wildlife Species
Observed Throughout the Yadkin Project Area
Wetland and Riparian Habitat Assessment

irds

Forested
Wetland Reservoir
Dependent
Forested
Wetland
Sapling
Shrub
Swam
Sparse
Shrub
Swam

Emergent
Wetland

Aquatic
Bed

Open
Water

pland
Blue jay Cyanocitta cristata x x
Bluebird, eastern Sialia sialis x
Cardinal, northern Cardinalis cardinalis x x x x
Catbird, gray Dumatellacarolinensis x x
Cedar waxwing Bombycilla cedrorum x
Chickadee, Carolina Poecile carolinensis x x x x
Chimney swift Chaeturapelagica x x x
Cook American Fulicaamericana x
Cormorant, double crested Phalacrocorax auritus x x
Crow, American Corax brachyrhynchos x x x x
Cuckoo, black billed Coccyzus erythropthalmus x
Cuckoo, yellow billed Coccyzus americanus x x x
Eagle, bald Halieetus leucocephalus x x
Egret, great Ardeaalba x x x x x
Egret, snowy Egretta thula x
Flicker Colaptes auratus x x x
Flycatcher, Acadian Empidonax virescens x x x
Flycatcher, great crested Myiarchus crinitus x x
Flycatcher, least Empidonaxminimus x
Flycatcher, willow Empidonax traillii x
Flycatcher, yellovthroated Empidonax flaviventris x
Gnatcatcher, blue gray Polioptila caerulea x x
Goldfinch, American Carduelis tristis x x
Goldfinch, American Carduelis tristis x
Goose, Canada Branta canadensis x
Grackle, common Quiscalus quiscula x x x x
Grebe, pied-billed Poddymbus podiceps x
Hawk, red-shouldered Buteo lineatus x x x
Hawk, red-tailed Buteo jamaicensis x x x x
Heron, great blue Ardeaherodias x x x x x
Heron, green Butorides virescens x x x x x
Indigo bunting Passerina cyanea x x x
Killdeer Charadrius vociferus x x
Kingbird Tyrannus x x x x
Kingfisher, belted Ceryle torquata x x x x x
Loon, common Gavia immer x
Mallard Anas platyrhynchos x x x x x
Martin, purple Progne subis x
Merganser, hooded Lophodytes cucullatus x
Mourning dove Zenaidamacroura x
Oriole, orchard lcterus spurius x
Osprey Pandionhaliaetus x x x
Owl, barred Strix varia x x
Phoebe, eastern Sayornisphoebe x x x
Pigeons Columba x
Plover, semi-palmated Charadrius semipalmatus x
Wetland and Riparian Habitat Assessment

irds

Forested
Wetland Reservoir
Dependent
Forested
Wetland
Sapling
Shrub
Swam
Sparse
Shrub
Swam

Emergent
Wetland

Aquatic
Bed

Open
Water

pland
Red-winged blackbird Agelaius phoeniceus x x x x
Robin, American Turdus migratorius x x
Sandpiper, spotted Actitis macularia x
Sapsucker, yellow bellied Sphyrapicus varius x
Sparrow, chipping Spizella passerina x
Sparrow, song Melospizamelodia x x x x
Swallow, bank Riparia riparia x
Swallow, barn Hirundo rustica x x
Swallow, cliff Petrochelidon pyrrhonota x x
Tanager, scarlet Pirangaolivacea x x
Tanager, summer Piranga rubra x x x
Teal, blue winged Anas discors x
Teal, green winged Anas crecca x
Tern, Caspian Sterna caspia x
Thrasher, brown Toxostoma rufum x
Thrush, wood Hylocichlamustelina x x x
Towhee Pipilo erythrophthalmus x
Tufted titmouse Baeolophus bicolor x x x
Turkey Meleagris gallopavo x
Vireo, red-eyed Vireo olivaceus x x x x x
Vireo, yellovkhroated Vireo favifrons x
Vulture, black Coragyps atratus x x x
Vulture, turkey Cathartes aura x x x x
Warbler, black and white Mniotilta varia x x
Warbler, magnolia Dendroica magnolia
Warbler, ovenbird Seiurus aurocapillus x
Warbler, Northern parula Parula americana x x
Warbler, prothonotary Protonotaria citrea x x x x x
Warbler, yellow Dendroica petechia x
Warbler, yellowt hroat Dendroica dominica x x
Waterthrush Seiurus noveboracensis x
Waterthrush LA Seiurus motacilla x
Wood duck Aix sponsa x x x x
Woodpecker, downy Picoides pubescens x
Woodpecker, red-bellied Melanerpes carolinus x x
Wren, Carolina Thyothorus ludovicianus x x x x

Reptiles
Anole, green Anolis carolinensis x
Anoles Anolis x
Fence lizard Sceloporus undulatus x
Skink, five-lined Eumeces fasciatus x
Skink, ground skink Scincella lateralis x x
Snake, "black" x
Snake, black racer Coluber constrictor x
Snake, brown water Nerodia taxisphota x
Snake, copperhead Agkistrodon contortrix x x
Wetland and Riparian Habitat Assessment

irds

Forested
Wetland Reservoir
Dependent
Forested
Wetland
Sapling
Shrub
Swam
Sparse
Shrub
Swam

Emergent
Wetland

Aquatic
Bed

Open
Water

pland
Snake, eastern king Lampropeltisgetula getula x
Snake, queen Regina semtemvittata x
Snake, ringneck Diadophis punctatus x
Turtle, box Terrepene carohna x x
Turtle, painted Chrysemys picta x x
Turtle, snapping Chelydra serpentina x
Turtle, spiny soft-shell Apalone spinifera x
Turtle, yellow bellied slider Trachemys scripta x x x
Turtles x x x

Amphibians
Bullfrog Rana catesbeiana x x x x
Chorus frog Pseudacris triseriata x
Green frog Rana clamitans x x x
Green tree frog Hyla cinerea x x x
Northern cricket frog Acris crepitans x x
Spring peeper Hyla crucifer x
S. chorus frog Pseudacris nigrita x x x
S. gray treefrog Hyla versicolor x
S. leopard frog Rana sphenocephala x
S.cricket frog Acris gryllus x x x
unid Cricket frog chorusing Acris spp. x x x
Salamander x
Salamander, N. dusky Desmognathus fuscus x
Salamander, slimy Plethodonglutinosus x x
Toad tadpoles x
Toad, American Bufo americanus x x
Toad, Fowlers Bufo woodhousei x
Toad, Southern bufo terrestris x x

Mammals
Beaver Castor canadensis x x x x
Muskrat Ondatra zibethica x
Raccoon Procyon lotor x
Red squirrel Tamiasciurus hudsonicus x
White-tailed deer Odocodeus virginicus x x x
Wetland and Riparian Habitat Assessment
APPENDIX C
Comment Response Table
Wetland and Riparian Habitat Assessment
Appendix C: Comment Response Table
Copies of the Wetlands and Riparian Habitat Assessment Study Draft Report were distributed to the
Wetlands, Wildlife and Botanical Issues Advisory Group (IAG) on February 18, 2005. The Draft
Report was then summarized and discussed at a March 2, 2005 meeting, and comments and
recommendations were made. Additionally, the IAG was given until April 1, 2005 to submit
additional comments. Table 1 below is a summary of the comments received and responses to the
comments.
Table 1: Summary of Comments and Responses
Source of Comment Comment Response
Wilson Laney, US Fish & Wildlife Include a table showing projected NAI prepared a table showing
Service, comment at 3/2/05 IAG wetland changes under hydrologic projected wetland changes under
meeting alternatives. several water level alternative
scenarios. This table has been added
to the Final Report as Table 10-1.
Chris Goudreau, NC Wild life Qualitatively assess functional trade- A qualitative assessment of the
Resources Commission, comment at offs of projected wetland changes functional tradeoffs of project
3/2/05 IAG meeting under hydrologic alternatives. wetland changes on various water
level alternatives has been added to
Section 10 of the Final Report.
Larry Jones, High Rock Lake The report fails to consider the gains The Final Report has been modified
Association, comment at 3/2/05 IAG that would be made at High Rock to better describe areas and to
meeting under the near-full, year round water estimate amounts of wetland
level scenario. The report should vegetation that would be expected to
include predicted quantitative develop under the near-full, year
increases in emergent wetlands round and other water level
under the various water level scenario s. See Section 10.1 and
scenarios. Table 10-1.
Andy Abramson, The Land Trust for Asked if GIS data layers for APGI will make the GIS data layers
Central North Carolina, comment at wetlands report would be made available to IAG members on
3/2/05 IAG meeting available to IAG members separate CD, upon request
Andy Abramson, The Land Trust for The conclusion drawn in the The FERC Project boundary around
Central North Carolina, 3/24/05 Wetlands study is that the forces High Rock Reservoir is generally the
email effecting the wetlands in and around 655' contour (local datum). Because
the upper most areas of High Rock the 655' elevation is the basis for the
Reservoir are primarily riverine, FERC Project boundary, it is also
including regular flooding and generally considered to be the
scouring. However, in the text of boundary of the influence of the
the RTE study, the 655' elevation is Project or its operation. For this
classified as that distance identified reason, the 655 boundary was
by APGI as the maximum influence chosen to represent the point of
of High Rock dam. This is a direct "maximum influence of High Rock
contradiction to the summary drawn Dam" for purposes of the most of
by NAI in the Wetlands study. the scientific studies done by APGI
as part of the Project relicensing
process. However, NAI's
assessment of wetlands around High
Rock Reservoir indicated that river
flows and the hydraulic and
hydrologic conditions associated
with the Yadkin River, rather than
reservoir operations (e.g., water
Wetland and Riparian Habitat Assessment
levels), are the primary influence on
wetlands found in the very upper
reaches of the reservoir. Given the
riverine, flowing water nature of
these reaches (along the Yadkin and
South Yadkin rivers and continuing
down the Yadkin River through the
upper end of the reservoir, in the
vicinity of the I-85 bridge), this
conclusion is neither contradictory
nor surprising.
Todd Ewing, NC Wildlife Resources Could stable lake levels improve the Fish and wildlife functions would
Commission, 4/15/05 email ecological function of wetlands on most likely be enhanced, whereas
High Rock? risks of IEPP invasions would also
increase. This issue is discussed in
Section 10.1 of the Final Report.
Todd Ewing, NC Wildlife Resources Is a shift from annuals to perennials There are few emergents currently
Commission, 4/15/05 email an improvement that could be occurring on High Rock, and stable
expected from stable lake levels on lake levels would undoubtedly allow
High Rock ? more emergents, mostly perennial,
to establish. This issue is discussed
in Section 10.1 of the Final Report.