PROJECT OVERVIEW
Aliso Water District (AWD), located in western Madera County, encompasses approximately 26,000 acres and relies primarily on groundwater for its water
supply. Following implementation of the Sustainable Groundwater Management Act (SGMA), the District became the local Groundwater Sustainability Agency and identified a need to import surface water to address long-term groundwater overdraft.
The Chowchilla Bypass (CBP) which traverses the District, provides an opportunity to capture high-flow surface water during flood events. AWD is pursuing an
appropriative water right to divert up to 10,000 acre-feet (AF) of water for groundwater recharge and on-farm recharge practices.
To support this effort, the District is proposing a 100 cubic feet per second (CFS) diversion structure along the CBP to convey water approximately 1.5 miles to a
75-acre recharge basin. The project is designed to offset an estimated annual groundwater deficit of approximately 2,500 AF and support long-term groundwater sustainability.
PROJECT COMPONENTS
- Low-flow diversion channel and reinforced concrete vault
- Dual 168-inch conical fish screens with riprap protection
- 72-inch pipeline with control gate structure and canal isolation
- Pump station and approximately 1.5 miles of 48-inch HDPE pipeline
- 75-acre groundwater recharge basin
DESIGN CONSIDERATIONS
The project was designed to maximize capture of high-flow events while addressing the District’s reliance on groundwater. System capacity and conveyance were sized to rapidly divert and deliver water to the recharge basin during short-duration, high-intensity flow events.
CBP provides a unique opportunity to capture excess flood flows from the San Joaquin River. The diversion system was designed to operate during these intermittent events, which typically occur during wet hydrologic cycles.
DIVERSION & CONVEYANCE SYSTEM
The project includes a turnout structure within the CBP consisting of a low-flow diversion channel, reinforced concrete vault, and dual 168-inch conical fish screens. Water is conveyed through a 72-inch pipeline across the levee to a landside pump station, then delivered approximately 1.5 miles via pipeline to the recharge basin.
The system is designed for high-flow capacity, sediment handling, and operational flexibility to support intermittent diversion conditions.
RECHARGE STRATEGY
The recharge basin was designed to offset groundwater overdraft while providing secondary flood system relief. Geologic investigations and infiltration testing confirmed the site is capable of sustaining recharge rates of approximately 0.75 feet per day.
The 75-acre basin provides approximately 231 acre-feet of storage capacity and can recharge up to 174 acre-feet per day, allowing the District to offset its annual groundwater deficit in a short operational window. To accommodate variable inflow conditions, the basin was divided into smaller cells to improve water distribution and operational control. The system is designed to accept inflows significantly higher than sustainable recharge rates, allowing the District to capture and store water during peak flow events and infiltrate over time.
