Transcript Instream Flow Needs Study

Instream Flow Needs and Reservoir
Elevation Study
Claytor Lake Project
FERC Project No. 739
Louis Berger Group
Thomas R. Payne & Associates
January 24, 2007 - Pulaski, Virginia
LBG/TRPA Experience with IFN
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Conducting IFN studies since 1981
Worked on 500+ instream flow studies
LBG and TRPA team frequently
Nearing completion of Smith Mtn. IFN
Currently conducting IFN studies
– New Melones Dam, Stanislaus River, CA
– Boundary Dam, Pend Oreille River, WA
– McCloud Pit Project, McCloud River, CA
Claytor Lake IFN Study Objectives
• Create incremental habitat indicies
• Review species life histories
• Compare regulated and unregulated flow
• Evaluate project effects on habitat
• Relate releases to reservoir elevations
– maintenance drawdown
– withdrawals and consumptive uses
• Assess means for getting public flow info
Claytor Lake IFN Study Components
• Physical Habitat Simulation of New River
– Calculate habitat indicies with PHABSIM
• Elevation study of Claytor Lake
– Impacts to recreational uses
• Dynamic flow routing model
– Travel time and flow attenuation
• New River water temperature modeling
– Thermal effects of alternatives
Highway 460 Bridge Glen Lyn
Study Area Map
Pembroke
County Line - Big Falls
~57 river miles
Radford
Claytor Lake Dam
PHABSIM Elements
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Habitat mapping
Transect selection
Hydraulic data collection
Computer calibration
Habitat suitability criteria
Physical Habitat Index - WUA/PHI ()
Regulated/unregulated hydrology
Interpretation
WUA/PHI () Habitat Index
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Flow in cubic feet per second
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Habitat Mapping
• Study reach is Dam to Highway 460 Bridge
• Mesohabitat strata typing on river
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run (medium and deep)
glide
pool (medium and deep)
fast riffle (boulder/bedrock)
slow riffle (gravel/cobble)
island
• Measured by strata by distance
• Data base for transect selection
Transect Selection
• Select from predominant and ecologically
significant strata
• Stratified random selection
• Minimum of 2 transects per strata
• Approximately 18-20 transects in selected
habitat strata
• Additional transects as necessary
• Selection in field with stakeholders
Hydraulic Data Collection
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Standard 1-D data collection
Three S-Q and one velocity data sets
River2D data collected at islands
Main channel velocities with ADCP
Edges and shallows with Price AA
Target flows (1000, 2500, 5000) cfs
Extrapolation range (400-12,500) cfs
ADCP
Teledyne Rio Grande Acoustic
Doppler Current Profiler
Tethered ADCP in Trimaran
Plot of ADCP Data
Computer Calibration
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Standard calibration methods and criteria
Use River2D for flow splits at islands
Use 1-Velocity (IFG4) model
Evaluate extrapolation limits
Simulate depths and velocities
Add substrate/cover coding
Habitat Suitability Criteria (HSC)
Target species list
Rock bass
Smallmouth bass
Flathead catfish
Channel catfish
Muskellunge
Redbreast sunfish
Bigmouth chub
Greenside darter
Logperch
Silver shiner
White shiner
Northern hog sucker
Pocketbook mussels
Purple wartyback mussels
Macroinvertebrates (3 species)
Crayfish
Hellbender
Riparian vegetation
Water willow
LIFE STAGES?
Computation of WUA/PHI ()
• Separate index for each species/life stage
• Standard multiplication of HSC variables
– mean column velocity
– depth
– substrate/cover
•  habitat index vs. discharge graphs
Interpretation of WUA/PHI ()
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Species/life stage prioritization
Species/life stage periodicity
Limiting factor evaluation
Time series modeling (hourly/daily)
– regulated/unregulated comparisons over time
– alternative flow regime comparisons over time
• Dual flow analysis of peaking effects
Reservoir Elevation Study
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Fall maintenance drawdown impacts
Withdrawal and consumptive impacts
Focus on recreational uses of reservoir
Data sources
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forebay elevations
flow releases
inflow data (Allisonia USGS gage)
reservoir stage-volume curves
• Model Excel-based or HEC-ResSim
Dynamic Flow Routing
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Compare stream gage data
Deploy additional gages as needed
Evaluate flow travel time
Evaluate flow change attenuation
Consider accretion and flow magnitude
Develop routing model (w/ temperature)
Assess means to communicate results and
predictions to public
Water Temperature Modeling
• Needed to assess themal impacts of routing
model and flow alternatives
• Deploy recording thermographs for year
• Allocate flow accretion among tributaries
• Select temperature model (SNTEMP)
• Calibrate temperature model
• Incorporate with flow routing model
• Focus on recreation and mussel populations
IFN Study Schedule
• Pre-study meeting - January 2007
• Review of habitat strata and target flows - March
2007
• Habitat mapping - April 2007
• Hydraulic data collection - May/June 2007
• Modeling and analysis - June-October 2007
• Progress meeting - August 2007
• Preliminary report - November 2007
• Meetings, discussions, comments, recommendations
- December 2007-April 2008
• Final report to stakeholders - June 2008