Woodard & Curran has a longstanding relationship with the California Department of Water Resources (DWR), both as an advocate for our clients and as a partner in developing programs aimed at sustainable water resources management. Under the DWR’s Basin Characterization Program, which provides the latest data and information to the state’s water agencies as a means of better understanding aquifer systems and groundwater management, our groundwater experts supported the development of the Aquifer Recharge Potential (ARP) Process Document. Published in March 2025, this document describes the datasets and analyses used to create ARP Maps, which identify locations with relatively higher potential for managed aquifer recharge (MAR).
The resulting maps are designed to support various MAR methods, including agricultural, on-field recharge, or recharge basins, and are tailored to achieve different recharge goals, including shallow well water supply, habitat rehabilitation, flood mitigation, and deeper aquifer recharge for subsidence mitigation. Analysis of parameters like soil conditions, groundwater levels, and aquifer texture, allowed the team to develop the ARP Maps to create a comprehensive set of sub-indices that rank and weigh these factors based on their importance to recharge potential. This innovative tool is a reliable resource for water managers, planners, and modelers that helps prioritize areas for investigation, preserve areas with high recharge potential, understand demands of future MAR operations, and integrate these insights into land use planning and water resource management strategies.
DWR hosts a monthly, virtual public meeting series designed for the basin characterization community to exchange ideas, share lessons learned, define needed guidance, and highlight research topics. Liz DaBramo, Project Engineer, and I are joining this month’s meeting, scheduled for 12:30 p.m. PST on Tuesday, April 22, to present the datasets, methodologies, and considerations for creating the ARP Maps, as detailed in the ARP Process Document.
Benefits of ARP Maps
Woodard & Curran has tailored MAR solutions for many California clients achieving a myriad of water resources goals. One example of such a project that the ARP Maps could have provided benefits to is in the city of Modesto, where Woodard & Curran provided design and implementation engineering services for a 22-acre-foot stormwater infiltration project, which the team sited at J.M. Pike Park. The project includes 11,000 feet of 18- to 60-inch storm drainage pipe directing stormwater to a percolation and storage vault beneath soccer and baseball fields. This project provides pretreatment and natural soil filtration to improve groundwater and surface water quality, while also incorporating park improvements that provide additional community benefits, such as efficient turf, drought tolerant trees, native plantings to foster habitats for pollinators, and new recreational fields.
Similarly, in the city of Inglewood, our experts designed a regional, multi-benefit stormwater capture and use project at Edward Vincent Jr. Park that replenishes groundwater resources and improves downstream water quality. Our scope of work included hydrologic and hydraulic modeling, quantifying stormwater capture capacities and long-term pollutant load reduction and providing an operation and maintenance plan with projected lifecycle costs. The project includes a dry creek channel, highlighting a historic water feature, as well as subsurface infiltration galleries and a bioretention area, all while providing improved park amenities, native landscaping, and educational features.
We are looking forward to using the ARP Process Documents and Maps to better inform our decisions as we plan, design, and implement successful MAR projects for our clients. Our work has helped enhance water supplies, support sustainable water management, reduce flood risks, support native habitats, improve water quality, mitigate subsidence, and reduce capital expenditures. The ARP Process Document and Maps provide a valuable resource for our groundwater experts and clients by reducing initial investigation time and effort. While further investigations are necessary to confirm site selection, this tool combined with our institutional knowledge and experience creates a sounder foundation for our clients to achieve sustainable water resources.
