(SRI) was used to evaluate road-stream crossings in the North River ...

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22 Φεβ 2014 (πριν από 3 χρόνια και 8 μήνες)

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Anne Wynn

Ecosystems
Investigations Program

Geological Survey of
Alabama


Application

of the Strategic Habitat Unit (SHU) Model

in North River


51 Strategic Habitat Units
(SHUs) and Strategic River
Reach Units (SRRUs) were
designated to focus
conservation activities for
managing, recovering, and
restoring populations of
Alabama’s rare fishes,
mussels, snails, &
crayfishes. The SHUs and
SRRUs include a
substantial part of
Alabama’s remaining high
-
quality water courses and
reflect the variety of
aquatic habitats occupied
by these species
historically and presently.

North
River

Location of the North River SHU

Before deciding the best way to
manage, restore, and recover
mussel populations in the North
River Watershed, a comprehensive
assessment of existing
environmental conditions needed to
be conducted. GSA performed fish
biotic integrity assessments,
mussel surveys, and rapid habitat
assessments throughout the
watershed. They also developed a
land cover/ land change dataset.
Previous water quality and
biological monitoring studies were
also documented and summarized
in the assessment. The data came
from various agencies including the
USGS, GSA, City of Tuscaloosa,
and ADEM. To access this
assessment, visit:

www.gsa.state.al.us/gsa/eco/pdf/OFR_0918.pdf

The potential nonpoint source index (PNPI)
method was
utilized to identify
nonpoint pollution sources on the broad landscape scale of the entire North
River Watershed. GIS grids of soil impermeability,
distance to
water,
slope, and
land cover
were established in
ArcMap

and the raster calculator was applied to
the PNPI equation (
5 * LCI + 3 * DI + 2 * ROI)
to produce the PNPI map.

Soils

Distance to water sources

Slope

Land Cover

Large PNPI
values are red on
the map, and represent
areas
having a high probability of
contributing nonpoint source
pollution. High risk areas
included
row crop
fields/barren land/clear
cuts/built up land with
impermeable soils on sloped
terrain in close proximity to a
stream. These areas have the
best chance of producing
rain runoff carrying sediment,
pesticides,
E. coli bacteria,
and
heavy metals to a nearby
water source.

This map can help prioritize
locations for stream habitat
and road
-
stream crossing
assessments.



The watershed
a
ssessment
was
not only
important for
SHU
restoration efforts, but
was
critical for the
development of
the

North
River Watershed
Management Plan. The
North River has
been listed
on Alabama’s 303(d) list
of
impaired waters since 1998
for siltation and nutrients.
The North River Watershed
Management Plan received
319 funding from ADEM in
2010.

Clear Creek

subwatershed

North River
Watershed

The watershed assessment findings
suggested that the most
robust
assemblage of mussel species in the
North River
Watershed was in
Clear
Creek.

Rapid habitat assessments
observed high
levels of
sediment deposition in
Clear Creek

and its
tributaries.

Clear Creek watershed

To quantify the current
sediment load in Clear
Creek, GSA installed two
OTT Orpheus Mini
Data
Loggers. These water
gauges began
recording
water level in Fall 2010.

Suspended sediment grab samples are
being collected at the
gauging stations.
Instantaneous measurements of specific
conductance, pH, temperature, dissolved oxygen,
&
turbidity
are
also recorded. A
standard Price AA or pygmy flow meter
is used
to
record flow measurements at cross
-
sectional
monuments at the gauging stations.

Clear Creek during low flow

Clear Creek during a flood event


Water quality data has been gathered during dry periods of low
base flow, winter flooding, and isolated summer storm events.

The gauge readings, water quality data, and flow measurements
are being used to calculate sediment
loading
rates in the Clear
Creek Watershed.

Once the water gauges had been installed and baseline water quality
data had been obtained, habitat threat and road
-
stream crossing
assessments began. These assessments helped to determine
locations for restorative
best management
practices

Rosgen

Stream Classification

Very helpful field manuals

PANAMA CITY

Fisheries Resource Office

HABITAT EVALUATION

Field Survey Procedures


June 2006


S
tream
habitat
and road
-
stream crossings were
evaluated using
methods
developed by
the USFWS (Chris Metcalf), Science
Applications International Corporation (Michael Rainer) and Troy
State University (Patrick
Witmer

and Paul Stewart). Chris Metcalf
provided orientation and field
training to
learn the
techniques
.
Dan Everson w / USFWS also helped our team become more
familiar with identifying stable and unstable channel morphology
using the
Rosgen

Stream Classification System.

11 variables = Habitat Threat Severity Index score


1
.

Water odors


2
.

Channel
stability


3
.

Channel
alteration


4
.

Shoring
structures


5
.

Fish
passage barriers


6
.

Riparian
buffer width


7
.

Local
non
-
point pollution


8
.

Floodplain
access


9
.

Bank
erosion

10.
Pipe
discharges

11. Bank

Erosion Hazard Index (
BEHI)

It takes at least 3 people to perform
instream

measurements during the
Stream Habitat Threat Assessment

Taking bank measurements in the

North River Watershed

Location of stream habitat
threat assessment sites on
Clear &
Deadwater

Creeks

ROAD
-
STREAM
CROSSING
SEDIMENTATION RISK
INDEX

A poorly maintained road
-
stream crossing is a
potential source of sedimentation to a stream.

The Sedimentation Risk
Index
(SRI)

was used to evaluate road
-
stream crossings

in the North River Watershed.

12 SRI metrics


This survey can be performed by a
single person, but two people make
it go much faster

SRI conditions

in the

North River Watershed



62 unpaved
and 69 paved
sites
were
assessed.



Out of 131 sites, 42 (32%)
were at
high
risk of
contributing
a lot of
sediment
to the adjacent
stream.



31
(73%) of
the
high risk
sites were unpaved.

What does
high risk

look like?

Unstable channel morphology

No riparian vegetation, incised
channel w/ high banks, and no
natural meandering indicate an
altered stream channel downstream
of the crossing.

Incised channel w/ high banks, and
excessive erosion downstream of
the crossing.

Bare soil /

bedrock ditches

AND

steep road approaches

R
oad crossing

fill erosion

Blocked culverts

BMP installed by Overhead Bridge on
Deadwater

Creek

Road
-
stream crossing and habitat threat assessment data has
helped establish BMP locations in the North River.
Water quality
data will continue to be collected until 2015 to determine if BMPs
are helping reduce the watershed’s sediment load.

Broadening the SHU partnership

The work done in the North River
needs to be performed in other SHUs
now. Partners
are
needed
to help
with SHU
watershed
assessments.
Assessment data will be hosted on a
forthcoming SHU website, which is
being developed by the USFWS.

The website will give the public
access to the SHU database in the
form of
a statewide
interactive map
.

Stream Habitat Threats and Road


Stream Crossing Assessment sites
will be uploaded to the interactive
map. This way Clean Water Partners
(this could be you!) and other
stakeholders will be able to see the
current conditions in
each SHU
and
where restoration
projects are
needed
.

Questions?

Anne Wynn

Ecosystems Investigation Program

Geological Survey of Alabama

http
://www.gsa.state.al.us/

Jennifer Pritchett

United States Fish and Wildlife Service

Daphne Field Office

http://www.fws.gov/daphne/

Contact Us

Acknowledgements