The McMullin Area GSA technical consultants have identified twelve projects potentially suitable for dedicated and on-farm groundwater recharge. Individual projects’ potential average annual yield ranges from about 3,200 acre feet (AF) per year to 29,000 AF per year. Many of the proposed sites have some combination of existing infrastructure and/or resources endorsing project feasibility, including pumping stations, canal systems, and basins that are tied to existing surface water supply sources. No surveying or design by the McMullin Area GSA has taken place and project consideration is solely conceptual based on input from McMullin Area GSA Board members, growers, and knowledge of the area.
A range of factors contributes to the success of implementing a recharge project at the proposed sites: acquisition of additional surface water supply in light of scarcity and existing water rights, project cost per acre foot of supply, willingness of cooperating agencies, and willingness of landowners to convert land use or sell property, among others. The McMullin Area GSA will use the varying factors as scoring criteria to help rank and prioritize the projects.
Heavily weighted on the list of criteria for the groundwater recharge projects is water supply availability. Potential surface water sources include the Kings River, Central Valley Project, and/or storm water from the Fresno area, although existing water rights pose a barrier in some cases to acquisition by the GSA. The availability of the water supply likely holds a higher maximum score potential than other criteria such as land use. The more sources of water supply available to a project site, the higher the score.
Many of the sites are poised with infrastructure components suitable for recharge, but improvements or additions would need to be made for project completion. This could include extending canal conveyance from surrounding irrigation districts to reach into the McMullin Area GSA, or enlarging existing canals to increase carrying capacity.
Groundwater recharge is one of the project types considered by the McMulllin Area GSA to stabilize groundwater levels and reach sustainability by increasing water supply. To complement projects, management actions that reduce water demand and improve data monitoring will also be implemented in the McMullin Area GSA. Projects and management actions, as well as their implementation plan, must be included in the Groundwater Sustainability Plan due to the State in January of 2020.