This collection consists chiefly of reports, handwritten notes and typewritten correspondence written and gathered by John S. Longwell. Although a few papers are from his early work (1910-1920) with the U. S. Reclamation Service, the main body deals with projects he became involved with as a consulting engineer, from his retirement in 1950 as General Manager and Chief Engineer at the East Bay Municipal Utility District, until his death early in 1960. His principal projects include the American River, Folsom and the Sonoma County Flood Control and Water Conservation District.