San Diego Water Storage and Efficiency Act of 2004

San Diego Water Storage and Efficiency Act of 2004 - Requires the Secretary of the Interior, in cooperation with the Sweetwater Authority public water agency in San Diego, to undertake an appraisal investigation of opportunities for construction of a three-reservoir intertie system to improve water supply reliability and water yield of the existing non-Federal water storage system. Directs that: (1) the appraisal report include a determination of whether to recommend the initiation of a feasibility study for the proposed intertie system; and (2) Federal obligations for costs of the investigation conform with reclamation policy.

Authorizes the Secretary to determine the feasibility of the reservoir and intertie system recommended. Directs that the feasibility report: (1) document the Secretary's engineering, environmental, and economic investigation of the proposed reservoir and intertie project, taking into consideration the range of potential solutions and the circumstances and needs of the area to be served, the potential benefits to the people of that area, and improved operations of the proposed reservoir and intertie system; and (2) indicate whether the proposed project is recommended for implementation.

Limits the Federal cost share to 50 percent. Directs the Secretary to submit a feasibility report and to seek appropriate construction and development authority for any recommended project.