Historic American Engineering Record: Stewart Mountain Dam

Historic American Engineering Record (HAER) No. AZ-12 presents a written historical summary and relevant historical documentation about the construction and use of Stewart Mountain Dam, a key component of the Salt River Project that provides water and power to the Phoenix Basin. The structure is also an important example of a radius arch dam designed using the trial load method.
Stewart Mountain Dam is one of a series of dams that along with the earlier Roosevelt, Horse Mesa and Mormon Flat Dams that are upstream from it, impounds water on the Salt River for use in generating power and for supporting irrigation and domestic use within the Salt River Valley. The dam is thus an important component of the Salt River Valley Water Users' Association's electric power generating system that provides service for much of central Arizona. Stewart Mountain Dam was constructed between 1928 and 1930 as part of the Salt River Valley Water Users' Association's initiative to expand power generation.
This HAER report focuses on the historical significance of Stewart Mountain Dam and on its technological nature and features. It discusses 1) the development of the Salt River Project; 2) increasing demand for electricity in central Arizona; 3) financing for the dam; 4) the design and construction of the Stewart Mountain Dam; 5) post construction alterations; and 6) the role the Salt River Project played in central Arizona economic growth. The report contains a narrative description, drawings, maps, and historic photographs of Stewart Mountain Dam.