To authorize the Secretary of the Army and the Administrator of the Environmental Protection Agency to conduct certain water projects for the purpose of improving water quality, and for other purposes.

Authorizes the Secretary of the Army to participate in the study, engineering, design, and construction of a regional water reuse system for southern California to provide a new water supply for agricultural, municipal, industrial, and environmental needs in that area. Requires the Secretary to report to specified congressional committees on the results of the study.

Authorizes the Secretary to study, engineer, design, and construct water reuse demonstration facilities in order to develop advanced technology for economically and environmentally sound alternative water supplies for the San Diego, California, metropolitan area. Requires a report from the Secretary on study results.

Authorizes the Administrator of the Environmental Protection Agency to participate with Santa Rosa, California, and other appropriate authorities in the design, planning, and construction of projects to treat waste water and store such treated water for such city and surrounding areas in order to: (1) provide new water supplies for agricultural, municipal, environmental, and other purposes; and (2) reduce the use of potable water supplies when treated waste water is a viable substitute.

Authorizes the Administrator to participate with Napa County, California, and other appropriate authorities in the expansion of the Soscol Wastewater Treatment Plant.

Limits the Federal share of each project's cost to 50 percent.