Study for Fish Screens at Existing Delta Facilities Dr. Leah Orloff Water Resources Manager CUWA Board MeetingJuly 24, 2009

- 2 - July 24, 2009 Study Objective Analyze the feasibility of pilot fish screens in the Delta for existing export facilities.

- 3 - July 24, 2009 Near-term and long-term benefits –Existing Delta exports are adaptively managed based on salvage of delta smelt and salmon –Existing Delta facilities are still necessary with any size Isolated Facility, including 15,000 cfs 2,000 cfs pilot screens will provide water supply reliability The Need for Fish Screens

- 4 - July 24, 2009 Current Operations No screening means no reliability In 2009, FWS adaptively restricted exports based on combined delta smelt salvage. –FWS tightened constraints from mid-May through June because of high salvage levels. –Despite the restrictions, pumps were shut down for 1-2 days at the end of May to avoid exceeding take limits. 2,000 cfs pilot screens would have prevented almost all salvage in spring 2008 and 2009.

- 5 - July 24, : 2,000 cfs screens would have prevented nearly all salvage

- 6 - July 24, : Fish screens would have saved up to 186 TAF Number of days in this month when cumulative salvage exceeded FWS take limit Acre-feet pumped at Banks this month when cumulative salvage exceeded FWS take limit If current FWS smelt take limits had been in place in spring 2008, they would have been exceeded in May, June, and July.

- 7 - July 24, 2009 Long- term, fish screens are needed for dual conveyance BDCP modeling shows –Continued reliance on existing Delta exports –Over 50% of supply from existing facilities in drier years 20% 75% 30% 50% 40% Average Exports (TAF/year ) Wet Above Below Dry Critical Normal Normal

- 8 - July 24, 2009 Pilot Project Study Project Management: –Funding partners will enter into an MOU –Two-tier management: Policy Team and Technical Team Schedule: All work to be completed within 6 months of consultant selection. Budget: $200,000

- 9 - July 24, 2009 Pilot Project Study Objective: Analyze the feasibility of pilot fish screens in the Delta for existing export facilities. Determine the best: –location –way to limit predation –way to ensure sweeping velocity –way to move fish out of the South Delta –way to avoid indirect impacts –improvement in water supply reliability

July 24, 2009 Scope of Work Task 1:Review previous studies Task 2:Develop conceptual alternatives Task 3:Assess alternatives for feasibility and benefits Task 4:Perform a blocking analysis Task 5Prepare materials for scientific review panel

July 24, 2009 Potential Screen Locations Feasibility studies will examine the best placement and design of fish screens to limit predation Positive barrier fish screens and tidal barriers provide sweeping velocities for fish survival North CanalWest CanalItalian Slough Screen Tidal Barriers Screen Tidal Barriers Screen Channel Modification

July 24, 2009 Extra Slides

July 24, : 2,000 cfs screens would have prevented nearly all salvage

July 24, 2009 In the near term, fish screens may ensure water supply reliability Number of days in this month when cumulative salvage exceeded FWS take limit Acre-feet pumped at Banks this month when cumulative salvage exceeded FWS take limit If current FWS delta smelt take limits had been in place in spring 2008, take limits would have been exceeded in May, June, and July, costing up to 182 TAF at Banks Pumping Plant Data

July 24, 2009 Tides provide sweeping velocity in the South Delta 0.4 ft/s

July 24, 2009 Screens Work CCWD’s Old River Intake screen prevents fish entrainment –12 years of operation –982 TAF diverted –Negligible effect on listed fish  Collected 1 delta smelt (June 2000, 18mm)  Collected 1 longfin smelt (April 2002, 22mm)  Collected 0 Chinook salmon and 0 steelhead

July 24, 2009 Fish Screens May Provide Benefit now and in the future Source: Wim J. Kimmerer, Matthew L. Nobriga. Investigating Particle Transport and Fate in the Sacramento- San Joaquin Delta Using a Particle Tracking Model. San Francisco Estuary and Watershed Science, Vol. 6, Issue 1 (February 2008), Article 4. Now: OMR restrictions limit South Delta exports Future: Dual conveyance will lower South Delta exports Fish that are successfully screened from exports have a greater likelihood of escaping the Delta during low export conditions.

July 24, 2009 Drafting a review report – synthesis of previous studies is a first stepDrafting a review report – synthesis of previous studies is a first step However …However … –DWR report is not examining current conditions  Outmoded technology  OMR restrictions have changed Delta hydrodynamics - may increase fish screen effectiveness  Fish screens may prevent SWP from reaching take limits –DWR may not have resources to do further studies Current DWR Efforts

July 24, 2009