CA AB1788

Modifies state cost-sharing for flood control projects authorized on or after January 1, 2002, allowing the state to pay up to 70% of nonfederal costs (instead of a fixed 50%) when recommended by the Department of Water Resources or Central Valley Flood Protection Board.

Authorizes increased cost-sharing (up to 70%) if projects result in significant contributions to objectives including endangered species/habitat protection, open space enhancement, recreational opportunities, or flood protection for state facilities.

Replaces previous criterion focusing on median household income thresholds with a new criterion to increase flood protection for "disadvantaged communities" as defined in Section 79505.5.

Requires the Department of Water Resources to develop regulatory criteria for determining whether projects make significant contributions to the prescribed objectives based on substantial evidence.

Applies to flood control and small flood management projects, with state payment recommendations included in department or board reports.