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In-Delta Fish Screen Facilities. Delta Wetlands Proposed Facilities and Basis for Re-Engineered Facilities. Webb Tract Diversions and Discharges. Bacon Island Diversions and Discharges. Now. Two Main Locations. Re-engineered. Diversion Plan and Elevation - 5/10/01.
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In-Delta Fish Screen Facilities Delta Wetlands Proposed Facilities and Basis for Re-Engineered Facilities
Bacon Island Diversions and Discharges Now Two Main Locations Re-engineered
Diversion Plan and Elevation - 5/10/01 Booster Pumps Located on New Levee Section Fish Screen
Proposed Fish Screen - 86 cfs each max. Hinged Pipe to Remove Screen when not in Use No Cleaning System
Some Existing Siphons to be Screened, but Contribution is Unclear Habitat Islands = 200 cfs (existing water right) Webb Tract = 4500 cfs 32 New Siphons/Pumps = 2750 cfs 7 Existing Siphons = 1750 cfs (or 250 cfs each???) Bacon Island = 4500 cfs 32 New Siphons/Pumps = 2750 cfs 28 Existing Siphons = 1750 cfs (or 62 cfs each??) ??? Typical Siphons are in the 10 -20 cfs max range…They are not proposed to be enlarged
DW Proposed Design Issues/Problems • Intake Screen Unproven at this Scale • Fish Screen Criteria Not Met • Screen Structure and Support Inadequate • Hinge, Screen, Piling, Bracing, Etc. • Pipe/Pump Hydraulic Issues • Settlement Impacts • Levee Stability Impacts • Erosion • Cyclic Loads and Fatigue • Retrofit of Existing Siphons Uncertain
Operations and Maintenance Issues • Manual Cleaning is Inadequate • Sedimentation and Dredging • Corrosion Potential and Cathotic Protection • Poor Access to Screens (cranes, boats) • Difficult Underwater Inspection • Settlement Monitoring and Adjustment • Flow Monitoring and Data Collection • Starting the Siphon • Pump Maintenance
Cleaning System Failure Andreotti Fish Screen 9/98
Potential Environmental Issues of DW Alternative • Fish Predation • Larval Fish Loss • Recreation/Boating Limitations • Aesthetics • Pump Noise • Evaluation Facilities Needed • Maintenance Activities • Construction Impacts • Water Quality at Discharge Stations
Uncertain Retrofit of Existing Facilities for Screening • Old Siphon Pipe Adequacy • Electrical Requirements for Automation • Site Issues • Structural Adequacy
Fish Screen Criteria Drove Alternative Facilities Design at Intake Site • Screen area inadequate for manual cleaning • Screen mesh is too large • Screens over 40 cfs subject to hydraulic uniformity and siting criteria • Not a “Distributed Intake” concept
Potential Benefits of Re-Engineered Consolidated Facility • Operations • Maintenance • Structural Integrity • Hydraulic Improvements
Example of Consolidated Facility CCWD Los Vaqueros IntakeOld River Pump Station
Example of Consolidated Facility RD108 830 cfs Sac. River