Santa Ana River Main Stem Including Santiago Creek, Counties of Orange, Riverside, and San Bernardino, California. Phase I General Design Memorandum. Main Report and Supplemental Environmental Impact Statement

摘要

The current plan for the main stem of the river includes construction of the Mentone Dam; flood plain management between Mentone Dam and Prado Reservoir; raising Prado Dam 30 feet and the acquisition line 10 feet; acquisition of the Santa Ana Canyon flood plain; channelization of the lower Santa Ana River; and acquisition, and preservation, of 92 acres of marshland at the mouth of the Santa Ana River. An integral part of the plan for Prado Dam, the Oak Street Drain plan involves construction of the channel recommended in the 1975 Survey Report from an existing debris basin to Prado Reservoir. The Santiago Creek plan involves detection storage of 100-year floodflows at existing gravel pits, with minimum downstream channelization. Facilities for recreation are included in the plans for the Santa Ana River and for Santiago Creek.