The collection consists of correspondence, reports, documents, and memoranda, relating to California's Central Valley Project, Lake Tahoe, East Bay Municipal Utility District, Pacific Gas and Electric Company, and public water and power supply system for other California municipalities.

The collection consists of correspondence, reports, legislation, and memoranda concerning the diversion of water from the Klamath and Trinity Rivers into the Sacramento Valley, California.

The collection consists of correspondence, reports, hydrological data, maps and memoranda pertaining to reservoirs, canals, water delivery systems, flood control and irrigation projects, water supply and land appraisals throughout California and southern Oregon, with particular reference to units of the Central Valley Project.

This collection is composed primarily of research files compiled for Hansen's study of federal-state relations in the Central Valley, which resulted in his dissertation, The Central Valley Project: Federal or State?(also published by the California State Assembly Interim Committee on Conservation, Planning and Public Works as Volume 13, no. 6, of the Committee's reports). Includes extensive interview notes, correspondence, reports, and detailed annotations of sources consulted.

The collection consists of reports, legal opinions, and comments concerning the Central Valley Project, water districts and reclamation districts, and water rights on the San Joaquin River and elsewhere in California.

The collection consists of correspondence, draft reports, papers, and news clippings pertaining to water resources development issues regarding State of California, Marin County, and San Francisco Bay Area.