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This document outlines potential betterments to be evaluated during the relicensing process of the Middle Fork Project. It includes inventory of betterments, improvements to water supply and power generation, and project operations. The document also discusses specific projects such as the Duncan Diversion trash rack, small hydro projects, turbine upgrades, pumped storage, and sediment management.
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Middle Fork Project Additional InformationPotential Project Betterments to be evaluated during Relicensing July 2006
Outline • Inventory of Betterments • Duncan Diversion trash rack • Small hydro projects (Interbay & Ralston) • Ralston turbine upgrade • French Meadows & Hell Hole raises • French Meadows Pumped Storage • Sediment management • Preliminary Environmental Review
Betterments are “Developmental Values” FEDERAL POWER ACT Section 4(e) In deciding whether to issue a license, the Commission must give equal consideration to developmental and environmental values. Environmental values include: fish and wildlife resources, including their spawning grounds and habitat, visual resources, cultural resources, recreational opportunities, and other aspects of environmental quality. Developmental values include power generation, irrigation, flood control, and water supply.
Purpose of Betterments • Improvements to water supply or supply reliability • Improvements to electric power generation • Improvements to project operations
Betterments Analysis for Relicensing Flow Chart Initial data collection & screening - Conceptual design work PCWA inventory of potential betterments Betterments to carry forward in relicensing Project Description, June 2006 We are Here Include viable projects in License Application Engineering/environmental studies and agency/public consultation 2007-2010
Duncan Creek Diversion • More water is available at the Duncan diversion • Main problem is blockage of the intake with trash during storms Upgrade trash rack structure to alleviate trash blockages May be constructed prior to 2013 as a maintenance item
Duncan Creek Diversion Intake
Add/Upgrade Small Hydro • Proposed • Upgrade Hell Hole powerhouse capacity • Add small hydro plants on flow outlets at Interbay and Ralston Afterbay Dams • French Meadows discarded - too remote, no power line • Analysis • Adjacent to existing MF Project facilities = easy access, construction, and operations. • Rough economic analysis based on $/KWhr costs
Add/Upgrade Small Hydro • Next Step • Include provision for fish release hydro facilities in Project Description for Relicensing. • Relicensing Instream flow studies • Finalize when flow release patterns established.
Ralston Capacity Increase • Hydraulic capacity of Middle Fork Powerhouse (1000 cfs) is higher than Ralston (925 cfs). • Ralston should have higher hydraulic capacity than Middle Fork otherwise spills at Interbay • Ralston Powerhouse is hydraulically limited – turbine limits output
Options at Ralston • Turbine- generator upgrade (if feasible) • Add second 11-MW unit
Ralston Capacity IncreasePotential Footprint (if Additional Unit option) Footprint
Ralston Capacity IncreaseOperations Impacts • Daily average water volume will be the same after upgrade • However, can move the daily volume through in fewer hours • More flexibility in generation • More flexibility in ancillary services • Additional 100 cfs (10% of flow capacity) allows concentration of generation in high value hours • Generally the same daily average project throughput • Generally the same daily average Ralston reservoir elevations
Ralston Next Steps • Evaluate upgrade potential of existing turbine/generator electrical equipment • Refine second unit option. • Evaluate electrical output constraints • Additional economic analysis & tracking of power market trends
French Meadows Storage Increase Additional storage of 5,000 AF potentially available as a result of safety repair Safety Repair = Spillway modification required by FERC to handle Probable Maximum Flood
French Meadows Spillway Spillway modification in preliminary design Implementation schedule not yet developed with FERC Project will require separate License Amendment (not in relicensing)
Potential Storage change, French Meadows Reservoir, with 5,000 AF Additional Storage Sample change to reservoir storage curve
French Meadows & Hell Hole ReservoirsProposed Operational Changes
Hell Hole Storage Increase 10 foot seasonal increase in operating level May–September would add 12 TAF
Typical Spillway Crest GatesGranite Reef Diversion - Arizona
Next Steps • Hydrology and Flood Routing • Optimization of seasonal operating elevations • Field Investigations • Environmental Studies • Refine layouts • Cost estimates and construction schedule • Incorporate in License Application
French Meadows - Hell Hole Pumped-Storage • Opportunity for pumped-storage between the reservoirs • 52 MW project maximizes use of hydraulic capacity in French Meadows Tunnel • Recovers lost head below French Meadows Powerhouse • 14 mile transmission line upgrade to Middle Fork
French Meadows/Hell Hole Pumped StorageOverview • Use of existing reservoir and tunnel facilities • Relatively large reservoirs = minimal water level fluctuations • Potential additional flexibility for peaking generation & ancillary services operations
French Meadows - Hell Hole Pumped StorageOperational Aspects • Net flow of water ‘downhill’ from FM to HH (thence through tunnels to rest of MFP) • Average net flows around 550 AF/day (wet yrs, Jul – Dec time period) • Surface change 4” to 6” per day (average) • Average net flows around 250 AF/day (dry yrs, Apr – Dec time period) • Surface change 2” to 4” per day
French Meadows - Hell Hole Pumped StorageOperational Aspects • Pump-back operations most likely on daily basis (pump/release cycle every day), more likely in summer/fall months • Maximum available for pumping: 6 – 10 hrs/day, moves 420 – 700 AF • Pumped volume < 0.5% of reservoir volume
French Meadows - Hell Hole Pumped StorageNext Steps • Preliminary design of selected betterments • Refined cost estimates • Refined operations analysis
Middle Fork Project Potential Betterments –Preliminary EnvironmentalEffects Analysis July 18, 2006
Potential BettermentsEnvironmental Analysis Approach Potential Betterment Effects Key Technical Resource Studies Potential Environmental Issues Environmental Analysis Avoidance, Protection, and Mitigation Measures
Potential Project Betterments Potential Effects • Short-Term Temporary Construction Effects • Long-Term Operational Effects • Long-Term Maintenance Effects
Potential Environmental Issues Short-Term Temporary Construction Effects • Traffic • Noise • Air Quality (dust, emissions) • Ground-Disturbance • Water Quality • Erosion • Operational Modifications (local and system) • Recreation
Potential Environmental Issues Long-Term Operational Effects • Reservoir Levels • Instream Flows • Generation • Water Supply • Water Quality - Temperature • Entrainment Long-Term Maintenance Effects • Increased Maintenance Area
Key Technical Studies (Existing Project) Terrestrial Resources • Special-Status Species (botanical and wildlife) • Invasive/Noxious Weeds • Tribal Plant and Wildlife
Key Technical Studies(Existing Project) Aquatic Resources • Physical Habitat • Water Quality • Fish Populations • Special-Status Amphibians and Reptiles • Hydrology • Fish Passage • Entrainment • Geomorphology • Riparian
Key Technical Relicensing Studies(Existing Project) Recreation Resources • Recreation Opportunities • Recreation Use and Future Demand • Facility Assessment and Needs Analysis Land Use • Aesthetics • Fire Protection/Prevention • Transportation and Circulation
Key Analytical Tool(Existing Project) Operations Model Characterize Effects on: • Generation • Water Supply • Reservoir Levels • Instream Flows
Project BettermentsAdditional Technical Study Requirements • Increased Survey Area • Additional Operational Modeling • Additional Environmental Analysis • Additional Technical Studies
Additional Study Requirements Short-Term Temporary Construction Effects • Increased Survey Area • Traffic • Ground Disturbance • Additional Operational Analyses • Additional Environmental Analyses • Noise • Air Quality (dust, emissions) • Water Quality • Erosion • Recreation
Additional Study Requirements Long-Term Operational Effects • Additional Operational Modeling • Reservoir Levels • Instream Flows • Generation • Water Quality – Temperature
Potential Additional Technical Studies Pump Storage • Entrainment • Reservoir Water Quality Modeling - Temperature
Next Steps • Additional Study Plan Discussions in Technical Working Groups