To amend the Central Valley Project Improvement Act to assist in efforts to avoid losses of juvenile anadromous fish.

Amends the Central Valley Project Improvement Act to limit the Secretary of the Interior's share of the costs associated with fish screens in the Patterson Irrigation District to 75% of the total cost of such activities to assist efforts in California to implement measures to avoid losses of juvenile anadromous fish resulting from unscreened or inadequately screened diversions on the Sacramento and San Joaquin rivers, their tributaries, the Sacramento-San Joaquin Delta, and the Suisun Marsh.