HomeMy WebLinkAbout20130412 Ver 1_Aquatic Pre-removal submitted 5-4_20150525Catena Proposal 15-053 May 4, 2015
Hoosier Dam Removal Pre-removal Baseline
1000 Corporate Drive, Suite 101
Hillsborough, NC 27278
(919) 732-1300
The
Catena
Group
May 5, 2015
Lynnette Batt
Director of Ecological Restoration
Unique Places
PO Box 52357
Durham, NC 27717
Subject: Hoosier Dam Removal Aquatic Pre-Removal Baseline
Chatham County, North Carolina
The Catena Group Proposal Number: 15-053
Dear Lynnette,
The Catena Group Inc. (Catena) is pleased to provide a task proposal for conducting pre-removal
aquatic community and habitat sampling as part of the Hoosier Dam Umbrella Mitigation Bank
(Bank) sponsored by 130 of Chatham, LLC in cooperation with Wildlands Engineering and
Unique Places (UP).
1.0 INTRODUCTION
The removal of the Hoosier Dam on the Rocky River is projected to result in the restoration of
16,060 feet of Rocky River (also known as Reeves Lake) and portions of six perennial tributary
streams under the existing reservoir pool. The project will involve the demolition and removal of
the Hoosier Dam with the goal of restoring the impounded stretch to pre-impoundment
conditions. The U.S. Fish & Wildlife Service (USFWS) has designated sections of the Rocky
River upstream and downstream from Hoosier Dam, as well as a section of Bear Creek just below
the dam, as Critical Habitat (CH) for the Cape Fear shiner (Notropis mekistocholas), a federally
listed endangered species. One of the benefits of removing the dam is to restore aquatic species
passage between these CH units which would be of substantial long-term benefit to aquatic
communities including the Cape Fear shiner.
The efforts described herein are proposed as part of the pre-removal baseline monitoring efforts
for the project. The following protocol addresses the first phase (pre-dam removal) of the
monitoring plan, and was developed in coordination with various members of the sponsor team,
and Catena’s experience working with the Interagency Review Team (IRT) for other dam
removal projects in North Carolina.
2.0 PROJECT SYNOPSIS
Several rare freshwater mussel and fish species are documented from this portion of the Rocky
River Subbasin that could benefit from these restoration efforts. As mitigation credits will be
released (in part) based on documented ecological improvements within the Rocky River, the
requisite monitoring program will involve two phases:
1)Pre-dam removal surveys in order to establish an existing condition of aquatic species
(mussel, macro-snail, and fish) in the impounded reaches and the adjacent free-flowing
“reference reaches” of the Rocky River
Catena Proposal 15-053 May 5, 2015
Hoosier Dam Removal Pre-removal Baseline
2) Annual or semi-annual post-dam removal monitoring of free-flowing reference reaches as
well as restored reaches for anticipated change in the aquatic species composition.
This proposal addresses first phase (pre-dam removal) monitoring for the following categories:
aquatic communities; aquatic habitat; rare, endangered or threatened species (RET); and water
quality via benthic macroinvertebrate communities.
Results from this pre-dam removal monitoring will be used to inform the development of
performance standards and associated success criteria. Please note: this proposal covers pre-
removal existing condition monitoring methods within the impoundment and reference
reaches only. Success criteria will be discussed and developed with the IRT separately, following
the results of the pre-removal surveys.
3.0 PRESURVEY INVESTIGATION
Prior to conducting field surveys, existing survey data in the project area will be reviewed.
Sources to be consulted are the NCNHP systematic inventory (database) of rare plant and animal
species, the NCWRC, and other available biological inventories.
4.0 FIELD DATA COLLECTION
Survey protocols developed for this effort will follow methods accepted by the scientific
community for each of the target faunal groups. The proposed post-removal aquatic community
biologic sampling will be completed at a minimum of 11 sites: four lotic sites located outside of
the impoundment (two upstream of the impoundment and two downstream of Hoosier Dam),
three sites within the impoundment, and one site on each tributary where mitigation credit is
being sought (tributaries 2, 3, 4, and 6).
The main purpose of the pre-removal surveys is to demonstrate differences in faunal community
assemblages between the impoundment and non-impounded reference reaches. As such, post
removal impoundment sites will be sampled to establish baseline conditions. These sites will be
distributed within the upper, middle and lower portions of impoundment respectively. In addition,
the four Rocky River reference sites (two upstream of the impoundment and two downstream of
Hoosier Dam) will be sampled. Two of the four tributary sites within the impounded reach will
also be sampled during pre-removal surveys, with two un-impounded tributary reference sites.
Existing condition aquatic species surveys will be conducted at the eleven locations sampled in
2015 (Table 1). The faunal groups targeted will be freshwater mussels, snails, fish and aquatic
macroinvertabrates.
Table 1. Pre-Dam Removal Surveys for Hoosier Dam Removal
Site #/Location
1: Rocky River Upstream 1
2: Rocky River Upstream 2
3: Rocky River Upper Impoundment
4: Rocky River Middle Impoundment
5: Rocky River Lower Impoundment
6: Rocky River Downstream 1
7: Rocky River Downstream 2
8: Tributary Impoundment A
9: Upstream Tributary A
Catena Proposal 15-053 May 5, 2015
Hoosier Dam Removal Pre-removal Baseline
10: Tributary Impoundment B
11: Upstream Tributary B
The sites selected outside of the reservoir pool will serve as target community reference reaches,
and may also help in determining direction (upstream vs. downstream) of recruitment into the
restored reaches after dam removal.
4.1 Mussel Surveys
Mussel surveys will be conducted as part of monitoring of aquatic communities and RTE species.
More species of freshwater mussels have been reported from the Cape Fear River Basin (29) than
any other river basin in North Carolina (Bogan 2002, Shelly 1987). Although no federally
protected mussel species are known from this basin, a number of rare mussel species are known
from this portion of the basin, including the Atlantic Pigtoe (Fusconaia masoni), Brook Floater
(Alasmidonta varicosa), Savannah Liliput (Toxolasma pullus), Yellow Lampmussel (Lampsillis
cariosa), Creeper (Strophitus undulatus) Eastern Creekshell (Villosa delumbis) and Carolina
Creekshell (Villosa vaughaniana). The Atlantic Pigtoe, Brook Floater and Savannah Liliput are
three of 404 aquatic species in the southeastern United States that the Center for Biological
Diversity (CBD), a nonprofit conservation organization (www.biologicaldiversity.org), petitioned
the U.S. Fish and Wildlife Service (USFWS) to list as either Threatened, or Endangered under the
Endangered Species Act (ESA) of 1973 as amended (CBD 2010).
Comprehensive survey efforts of each location listed in Table 1 are proposed to evaluate the
presence, species composition, relative abundance and distribution of freshwater mussel species
at each survey reach. The purpose of these surveys is to qualitatively and quantitatively
document the freshwater mussel community in the impounded reaches of the Hoosier Dam and
compare the community to the non-impounded reference sites. Mussels within similar types of
impoundments are generally restricted to river bank margins, while they occur in varying
abundances throughout the width of the channel in non-impounded habitats. As habitat
complexity increases within the impoundment following dam removal, relative abundances and
species diversity is expected to increase. Mussel populations are documented upstream and
downstream of the existing dam, thus recruitment of many species into the restored habitats can
come from both directions.
The proposed study plan will evaluate the following potential metrics:
1) increase in abundances and species diversity of mussel species more often found in
lotic habitats, and a decrease in the abundance of mussel species (Eastern Floater and
Paper Pondshell) found more often in lentic habitats.
2) increases in age/size class distribution within mussel populations
3) increase in the amount of occupied habitat, or distribution of mussels within the river
Two survey methodologies will be utilized. Surveys of the impounded reaches will utilize a
minimum three-person survey team using SCUBA (2 divers, 1 surface support and data recorder).
Communication with surface support will be maintained with AGA full face masks equipped with
underwater transceivers. Surveys in the un-impounded sites will be conducted using
mask/snorkel, or wading with view scopes.
Timed Qualitative surveys
Timed mussel surveys will be conducted by the survey crew within a defined area (i.e. 100 foot
section) at each of the sampling locations. All mussels will be collected, identified, counted, and
returned to the substrate. The results of these surveys will provide an account of species diversity
Catena Proposal 15-053 May 5, 2015
Hoosier Dam Removal Pre-removal Baseline
at each site as well as an estimate of the relative abundance for each species as measured by
Catch Per Unit Effort (CPUE).
Quantitative Transect Surveys
As mentioned above, mussel habitat within impoundments is generally limited to bank margins,
compared to free flowing habitats where mussels are more distributed throughout the channel. To
assess the distribution of mussels across the river channel, a 12-foot wide cross-river transect will
be established at each survey location, with the two divers surveying a twelve foot wide area
along a weighted transect line stretched across the river bottom. Habitat within the river channel
will be segmented into segments of equal length (A, B, C, or right, center, left). The transect
location will be staked with rebar on both sides of the river and recorded using a sub-meter GPS
device to allow for repeat surveys. The specific amount of area and time surveyed in the separate
segments will be recorded at each transect. Habitat conditions within each segment will be
recorded and characterized, and the location of the thalweg at each transect will be recorded.
This will allow for comparison of species composition, abundance and distribution within and
between sites.
All species of freshwater bivalves will be recorded, photographed, and returned to the substrate.
Those monitored by the NCNHP will be measured and checked for evidence of reproduction. If
any federally protected species are found during the survey efforts, the location will be recorded
using GPS and each individual returned to where it was found. Per Scientific Collection Permit
requirements, UP, USFWS, and NCWRC will be notified of the findings.
4.2 Snail Surveys
The mussel monitoring studies will also incorporate some snail species, as they are surveyed for
in a similar manner, and are usually recorded during most mussel surveys. This proposal does not
suggest that changes in aquatic snail fauna be identified as essential; however, if colonization of
the former impoundment by lotic-adapted snail species such as the Gravel Elimia (Elimia
catenaria) is noted after dam removal, this would lend further support to the establishment of the
“appropriate” aquatic community. The Gravel Elimia is known to occur in free flowing portions
of the Cape Fear River Basin. Colonization of this species following dam removal would indicate
restoration to lotic conditions. Snail surveys will be conducted in conjunction with the mussel
survey using similar methodology. Snails will be hand picked from rocks and woody debris and
dip nets will be used to sift through leaf packs.
4.3 Fish Community Surveys
Catena will develop a post-removal fish monitoring plan that will determine if an “appropriate”
fish community is re-established following dam removal. This plan will be developed in
coordination with the sponsor and IRT members. The purpose of the pre-removal existing
condition surveys is thus intended to demonstrate general faunal differences between impounded
vs. un-impounded sites by establishing species composition within the respective reaches.
4.3.1 Un-impounded Reaches
Due to the concern with electro-shocking impacts on the Cape Fear Shiner, this methodology will
not be employed within un-impounded sections of the Rocky River. The fish faunal composition
at these sites will be sampled using seine netting and dip netting techniques. While these
methods will not provide a complete list of all species occurring within these areas, they are
effective at capturing various lotic adapted species such as shiners and darters.
Catena Proposal 15-053 May 5, 2015
Hoosier Dam Removal Pre-removal Baseline
4.3.2 Impounded Reaches
The use of a boat shocker as the primary sampling technique is the most effective method for
sampling the fish community in an impounded habitat. Thus, Catena is proposing to conduct fish
surveys within the impoundment using a boat electroshocking unit, at three impoundment sites.
The sites will be chosen based upon accessibility and habitat suitability, and will be dispersed in
the lower, middle and upper portions of the impoundment, as well as within the impounded
portions of two of the four tributaries. A 14-foot aluminum boat, equipped with an electrofishing
apparatus consisting of an electrode configuration of two anodes, each with a terminal six wire
umbrella array, extended out from the bow at approximately 25°, and with the aluminum boat
acting as the cathode, will be used to sample three cross river transects spaced 100 feet apart at
the three sampling locations (producing spatial replicates at each location). Every effort will be
made to net any observed fish that do not rise completely to the water surface. Once netted, fish
will be held in aerated live well buckets until processing, which will take place on the shoreline at
the end of each transect line. Habitat attributes such as channel width, along with water depth
and substrate composition along the transect line, will be recorded. Captured fish will be
identified, counted and returned to the river after processing. The results of these surveys are
expected to demonstrate that the fish community within the existing impoundment is comprised
of lentic adapted species.
4.3.2.1 Supplemental Visual Surveys
Visual surveys of fish species will also be conducted in conjunction with the mussel surveys
using SCUBA. While this method is generally not useful in gathering population data, it is
effective in determining presence of benthic species such as darters, as well as more pelagic
schooling species such as shiners. Catena staff is familiar with doing visual fish identifications
underwater. In most cases, fish observed will be identified to species; however, in other instances
identifications may only be possible to genus, or sub family level. Water clarity and fish behavior
will influence the level of identification that will be possible.
4.4 Benthic Macroinvertebrate Surveys
The eleven pre-removal locations will be sampled one time utilizing methodology described in the
NCDWR’s Standard Operating Procedures for Collection and Analysis of Benthic
Macroinvertebrates, Version 4.0 December 2013. Where applicable, sites will be sampled utilizing
the Standard Qualitative Method, Qual 4 Method, or Swamp Method depending on the watershed
size and habitat. Qualitative collections of aquatic macroinvertebrates will be made with D-frame
aquatic dip nets, kick nets, a #30 sieve sand sample, and hand picking organisms from substrates. A
multiple habitat approach will be used, where specimens from all available habitats (stream margins,
leaf packs, aquatic vegetation, detritus, woody debris and logs, and sand accumulations) are
combined to form one aggregate sample. Samples will be sent to a NCDWR certified laboratory
for identification. Techniques utilized will allow for identification of taxa to species level and
calculation of taxa richness. The primary output for this sampling method is a taxa list with an
indication of relative abundance (Rare, Common, Abundant) for each taxon. Baseline stream
chemistry (temperature, conductivity, pH, and dissolved oxygen) will be conducted in
conjunction with benthic sampling.
4.5 Physical Habitat Surveys
A functional stream assessment will be conducted within the Rocky River conditions according to
the (NCSAM) North Carolina Stream Assessment Method. The NCSAM determines the level of
stream function relative to reference conditions and provides a function rating of High, Medium,
Catena Proposal 15-053 May 5, 2015
Hoosier Dam Removal Pre-removal Baseline
or Low. Assessment sites will be located upstream, within, and downstream impoundment. The
evaluation will be repeated at the same sites after dam removal. Stream functions and sub-
functions in pre-removal lentic conditions within the impoundment will be compared to the post-
removal lotic conditions attributed to the dam removal. According to the NCSAM, dams can
severely change aquatic communities in streams and are considered an alteration and stressor that
affects all three primary functions evaluated for NCSAM: hydrology, water quality, and habitat.
There are 25 metrics evaluated to determine stream function. As the lentic conditions change to
lotic conditions, as many as 12 metrics that will likely be affected include flow restriction
evidence, longitudinal profile, streamside area interaction, water quality stressors, bedform and
substrate, aquatic life, wetland presence, buffer width, buffer structure, continuity of vegetated
buffer, vegetation composition, and conductivity.
5.0 CONCLUSION
The existing condition sampling protocol described in this proposal along with the post-removal
monitoring plan that will be subsequently developed are designed in a scientifically sound and
cost effective manner. This data will be used to inform the development of success criteria and
associated metrics.
Pre-removal and post removal survey methodologies will vary due to the changes in physical
habitat conditions that will occur following dam removal. Qualitative and semi-quantitative
sampling during pre-removal surveys will establish that the existing faunal community
composition within the current impoundment is significantly different than un-impounded
sections of the river both upstream and downstream. The post-removal monitoring protocol will
then qualitatively and quantitatively monitor the faunal community changes in response to dam
removal and determine if the targeted metrics are met.