Whitewater River/Colorado River Aqueduct Siphon Scour and Mine Reclamation Project

Whitewater River/Colorado River Aqueduct Siphon Scour and Mine Reclamation Project

NOTE: Revised Metropolitan is proposing 3 improvements related to its CRA. Two of the improvements would protect siphons from scour effects caused by erosion within the Whitewater River, and potentially at the WMP. The third improvement would prevent over-pressurization of the CRA in the event the San Jacinto Tunnel becomes blocked. The first improvement would include the installation of scour protection devices (i.e., a gabion wall), which would generally involve: (1) the replacement of an existing earthen berm upstream of the CRA siphon with an ~800 ft long, 12 ft wide (at the base), and 9 ft high gabion wall consisting of rock-filled cages; (2) placement of rocks to backfill a 15 ft high erosional feature directly adjacent to the downstream side of the CRA siphon's protective concrete apron; and (3) relocation of soil from the existing earthen berm to behind the newly constructed gabion wall. The second improvement would entail reclamation of the WMP, and would generally involve: (1) borrowing spoil material from the Cabazon Spoil site, created when the CRA was constructed about 70 yrs ago; (2) transporting the spoil material (and minor excess material from the Cabazon Radial Gate site) via haul truck; (3) depositing the material int eh WMP; and (4) revegetating the disturbed areas. The third improvement, at the Cabazon Radial Gate Facility, would generally involve (1) the removal of the radial gate at the San Gorgonio Wasteway; (2) the widening of ~100 ft of the existing concrete lined waste-way channel that conveys water to the San Gorgonio River; and (3) the replacement of the steel radial gate with a 125 ft long reinforced-concrete weir structure.

Desert Hot Springs

Riverside

Air Resources Board, Major Industrial Projects, California Department of Conservation (DOC), California Department of Parks and Recreation, California Department of Public Health (CDPH), California Department of Transportation, District 8 (DOT), California Public Utilities Commission (CPUC), California Regional Water Quality Control Board, Colorado River Basin Region 7 (RWQCB), California State Lands Commission (SLC), Colorado River Board, Department of Fish and Wildlife, Region 6, Department of Toxic Substances Control, Office of Historic Preservation, Resources Agency, State Water Resources Control Board, Division of Water Rights, California Native American Heritage Commission (NAHC)

California Native American Heritage Commission (NAHC)

Water Facilities , Mining (Mine Reclamation)

Other

Aesthetics, Agriculture and Forestry Resources, Air Quality, Biological Resources, Cultural Resources, Cumulative Effects, Drainage/Absorption, Flood Plain/Flooding, Geology/Soils, Hydrology/Water Quality, Land Use/Planning, Mineral Resources, Noise, Public Services, Transportation, Vegetation