POTATO OR POT-ENTIAL AQUIFER RECHARGE? DEVELOPMENT AND APPLICATION OF SUBSURFACE RECHARGE ANALYSES

The Aquifer Recharge Potential (ARP) analyses represent a significant advancement in identifying favorable locations for managed aquifer recharge. This approach, implemented across multiple local investigation areas, focuses on subsurface texture and flow paths. It dives deep into underground, natural infrastructure for recharge, supplementing other recharge suitability indices that consider anthropogenic factors such as land use and water conveyance. The ARP maps, developed as part of the Department of Water Resources' Basin Characterization Program, integrate a three-dimensional subsurface texture model that co-kriges coarse fraction data from boring logs and Airborne Electromagnetic (AEM) surveys. This model reveals interconnected coarse bodies and flow paths, average sediment coarseness by aquifer depth, and depth to impeding clay layers.

In addition to the texture model, the ARP analysis incorporates datasets for near-surface soil percolation and depth to water. Each factor is scored and weighted based on their importance to recharge. The maps cater to various recharge methods, including on-farm recharge, recharge basins, and dry wells, and target different aquifer depths and management objectives. The resulting ARP maps highlight areas with relatively high infiltration rates and significant water storage potential, supporting local water managers in their recharge investigations. This presentation will demonstrate the development, application, and lessons learned from ARP analyses. It will illustrate how ARP maps can serve as a valuable tool for water managers, supporting them in making informed decisions regarding recharge opportunities.