Phoenix - Bon Tempe Connection Project

Phoenix - Bon Tempe Connection Project

Marin Water proposes to improve operational efficiency and flexibility and allow for more frequent use of Phoenix Lake water without the intensive system modifications that are required under current conditions. Marin Water would construct a dedicated welded steel, 18-inch diameter raw water pipeline between the barge pump (Pump 1) in Phoenix Lake and the Bon Tempe Reservoir shoreline. Approximately 6,310 linear feet of new pipeline would be constructed and would mostly follow existing trails and fire roads. At Bon Tempe Reservoir, the pipeline would be installed alongside existing pipes and water would enter the reservoir from the Bon Tempe shoreline. No new inlets or outlets would be required for Phoenix Lake. Two pumps would be required to convey the water over the 500-foot elevation change between the two lakes. Pump 1, the Barge Pump station, would be upsized and Pump 2 would be installed in a new building adjacent to the existing Phoenix Transfer Pump station. This pump station building would be approximately 30 feet long, 15 feet wide and 15 feet tall and would include a new 400 hp pump and associated electrical equipment. The new building would include noise attenuation measures such as louvers or venting that is oriented away from trail users and recreationists. The Project would be constructed in two phases: Phase 1 would occur from August 1, 2024, to January 31, 2025, and Phase 2 would occur from August 1, 2025, to January 31, 2026, to avoid impacts to the Northern spotted owl. No construction activities would occur during the February 1 to July 31 nesting season. Construction staging, laydown, and worker parking would take place at existing parking/staging areas at Phoenix Lake and Bon Tempe Reservoir. During Project operations, Phoenix Lake water would be moved to Bon Tempe Reservoir during dry years. Pumping would occur continuously over 28 days to convey a total of 260-acre feet of raw water at a rate of 3 million gallons per day. The water would only be conveyed during late fall to early winter and/or early to late spring but would not be conveyed during the summer or early fall when Phoenix Lake would not be able refill before the dry season.

Unincorporated Area

Marin

Citywide, Countywide, Northern California, San Francisco Bay Area, Unincorporated

California Air Resources Board (ARB), California Department of Fish and Wildlife, Bay Delta Region 3 (CDFW), California Department of Parks and Recreation, California Department of Toxic Substances Control (DTSC), California Department of Transportation, District 4 (DOT), California Department of Transportation, Division of Aeronautics (DOT), California Department of Transportation, Division of Transportation Planning (DOT), California Department of Water Resources (DWR), California Highway Patrol (CHP), California Native American Heritage Commission (NAHC), California Natural Resources Agency, California Regional Water Quality Control Board, San Francisco Bay Region 2 (RWQCB), California State Lands Commission (SLC), Office of Historic Preservation, State Water Resources Control Board, Division of Water Quality, State Water Resources Control Board, Divison of Financial Assistance

Water Facilities (260 acre feet twice/year (each time for 28 days))(Type Storage, MGD 520)

Water

Aesthetics, Agriculture and Forestry Resources, Air Quality, Biological Resources, Cultural Resources, Cumulative Effects, Drainage/Absorption, Energy, Flood Plain/Flooding, Geology/Soils, Greenhouse Gas Emissions, Growth Inducement, Hazards & Hazardous Materials, Hydrology/Water Quality, Land Use/Planning, Mandatory Findings of Significance, Mineral Resources, Noise, Population/Housing, Public Services, Recreation, Septic System, Sewer Capacity, Solid Waste, Transportation, Tribal Cultural Resources, Utilities/Service Systems, Vegetation, Wetland/Riparian, Wildfire