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.

The collection consists of correspondence, news clippings, memoranda, office files, legal documents, drafts of legislation, and transcripts of hearings. Principal topics include area planning, flood control and drainage, garbage and refuse collection and disposal, sewerage and industrial wastes, water quality management, water resources development (both state and federal), and water supply and distribution.

The collection consists of 14 notebooks that describe contracts and project plans for drainage and channels of Riverside county.

This collection consists of data, reports, plans, books, articles, of Riverside County and Southern California water. Induded are detailed records of this area's water condition and consumption from 1912 to 1999. Detailed recordings of the temperature of the city of Riverside are included.