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 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 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

Hinge Design Loads and Fatigue

Cleaning System Failure Andreotti Fish Screen 9/98

Material Selection Considerations

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

Siphon Screen Example Horseshoe Bend (30 cfs)

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 Intake Old River Pump Station

Example of Consolidated Facility RD108 830 cfs Sac. River