Design of native species habitat restoration concept sites on the Lower Colorado River

Six sites suitable for protected native fish and riparian habitat restorati on were identified in the report "Synthesis Report of Ecological Restoratio n Concepts for the Lower Colorado River" (U.S. Bureau of Reclamation, 1999) Site selection was completed after a review of existing information and fi eld reconnaissance was conducted, critical design issues and constraints we re addressed, and opportunities for coordination with other programs were i dentified. Several physical and programmatic issues were important to the d esign process. Water management issues were especially critical, and includ ed designing a system to supply water to historical floodplains from heavil y incised channels, determining necessary volumes and timing of water for s ite hydration, designing inflow and outflow control structures for fish hab itat, providing adequate water in a fully-allocated system, and recreation of some features of typical historical annual hydrographs. Soil salinity wa s a critical controlling factor in riparian vegetation establishment, and d epth to water table was a central design feature to ensure a year-round hab itat for native fish. Other design features included ensuring that water le vel changes would not adversely affect nearby land owners, estimating capit al and continuing costs, developing an operation and maintenance plan, and identifying data gaps.