California Reclaimed Water Act for the 21st Century

California Reclaimed Water Act for the 21st Century - Amends the Reclamation Wastewater and Groundwater Study and Facilities Act to authorize the Secretary of the Interior to: (1) coordinate projects for the reclamation and reuse of water under such Act with projects and programs under the CALFED Bay-Delta Program; and (2) take into account Federal expenditures for projects under such Act in making determinations under the CALFED Program relating to the equitable implementation of ecosystem restoration and water management. Requires project compliance with the National Environmental Policy Act of 1969.

Authorizes the Secretary to: (1) participate in the design, planning, and construction of the Castaic Lake Water Agency reclaimed water project, the Clear Lake Basin water reuse project, the Inland Empire regional water recycling project, the San Pablo Baylands water reuse projects, the Lower Chino Area desalination demonstration and reclamation project, the West Basin Comprehensive Desalination Demonstration Program in Los Angeles County, and the City of Los Angeles Water Recycling Program (replaces existing provisions authorizing the Secretary's participation in the Los Angeles area water reclamation and reuse project); (2) provide design and construction assistance for the East Bay Municipal Utility District/Dublin San Ramon Services District advanced wastewater reuse treatment project; (3) provide assistance to California in carrying out projects under the California water recycling program; and (4) carry out programs to assist agencies in projects to construct regional brine lines in the San Francisco Bay and Santa Clara Valley areas and to export the salinity imported from the Colorado River to the Pacific Ocean.

Directs the Secretary to carry out a program in cooperation with the Water Reuse Foundation to conduct research concerning water reuse in relation to public health, water quality, new technology, salt management, economics, and ecosystem restoration.

Adds a separate Federal cost share limitation with respect to the San Gabriel Basin demonstration project.