1. In-Delta Fish Screen Facilities
Delta Wetlands Proposed Facilities and Basis for Re-Engineered Facilities

2. Webb Tract Diversions and Discharges

3. Bacon Island Diversions and Discharges
Now
Two Main
Locations
Re-engineered

4. Diversion Plan and Elevation - 5/10/01
Booster Pumps Located on New Levee Section
Fish Screen

5. Proposed Fish Screen - 86 cfs each max.
Hinged Pipe to Remove Screen when not in Use
No Cleaning System

6. 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 cfs max range…They are not proposed to be enlarged

7. 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

8. 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

9. Hinge Design Loads and Fatigue

10. Cleaning System Failure
Andreotti Fish Screen
9/98

11. Material Selection Considerations

12. 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

13. Uncertain Retrofit of Existing Facilities for Screening
Old Siphon Pipe Adequacy
Electrical Requirements for Automation
Site Issues
Structural Adequacy

14. Siphon Screen Example Horseshoe Bend (30 cfs)

15. 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

16. Potential Benefits of Re-Engineered Consolidated Facility
Operations
Maintenance
Structural Integrity
Hydraulic Improvements

17. Example of Consolidated Facility
CCWD Los Vaqueros Intake Old River Pump Station

19. Example of Consolidated Facility
RD108
830 cfs
Sac. River