Shallow Well Drilling and Water Conservation Project

Shallow Well Drilling and Water Conservation Project

The shallow well drilling portion of the Project would involve the construction and operation of two new agricultural irrigation wells screened above the Corcoran Clay so that their use could reduce the District’s reliance on the lower aquifer water. Well No. 1 would be located roughly at the midway point on the eastern edge of APN 074-030-011 near the Eastside Canal. Well No. 2 would be located roughly at the southeastern corner of APN 065-050-004 near the Eastside Canal. The new wells would be drilled to a maximum depth of approximately 200 feet. Up to two existing wells that have been drilled and screened below the Corcoran Clay may be abandoned as part of the Project. Transitioning pumping from the deep aquifer below the Corcoran Clay to the shallow aquifer above the Corcoran Clay would reduce subsidence over the long term. A Variance application approved by Merced County would be required to allow the two new wells to be located at a distance closer to the existing deep wells and a surface waterway than would normally be permitted (300 and 100 feet, respectively). The water conservation portion of the Project would involve the modification of three existing weirs along the Mariposa Slough, and construction of two recharge basins adjacent to the Mariposa Slough. The weirs would be equipped with automated canal gates and flow measurement devices. Additionally, the existing pumps at each weir would be replaced with new pumps and would be sized with a capacity of up to 35 cubic feet per second (CFS). The new pumps which would return water to the head of the District’s system and avoid or reduce losses in the last reach of Mariposa Slough. One recharge basin would be approximately 30 acres and would have the capacity to store up to 150 acre-feet (AF) of water. The second recharge basin would be approximately 23 acres and would have the capacity to store up to 115 AF of water. Both recharge basins would be constructed with levees that would be built up to a maximum height of six feet tall and would be comprised of excavation material from the proposed basin construction. No excavation material would be exported as it would be balanced onsite. Water would be diverted to each recharge basin via proposed pumps connecting to the Mariposa Slough. Each pump would have a conveyance capacity of up to 70 CFS. The proposed Project would allow the District to store surface water when available and delay the pumping of lower aquifer wells, thereby reducing strain on the groundwater resources from which these wells draw.

Merced

Merced

Northern California

California Air Resources Board (ARB), California Department of Conservation (DOC), California Department of Fish and Wildlife, Central Region 4 (CDFW), California Department of Forestry and Fire Protection (CAL FIRE), California Department of Parks and Recreation, California Department of Toxic Substances Control (DTSC), California Department of Transportation, District 6 (DOT), California Department of Water Resources (DWR), California Governor's Office of Emergency Services (OES), California Native American Heritage Commission (NAHC), California Natural Resources Agency, California Regional Water Quality Control Board, Central Valley Fresno Region 5 (RWQCB), Central Valley Flood Protection Board, Office of Historic Preservation, State Water Resources Control Board, Division of Drinking Water, District 12, State Water Resources Control Board, Division of Drinking Water, District 24, State Water Resources Control Board, Division of Water Rights, State Water Resources Control Board, Divison of Financial Assistance

Other (Shallow Well and Water Conservation Project)

Shallow Well and Water Conservation Project

Biological Resources, Cultural Resources, Geology/Soils, Tribal Cultural Resources