Evaluation of Groundwater Supply Alternatives Within Bernal Subbasin

REGIONAL GROUNDWATER FACILITIES PROJECT FEASIBILITY STUDY 18 Zone 7 Water Agency December, 2025 For average and wet years, Zone 7 similarly plans to cap groundwater production at approximately 6,500 AFY, since other water sources are generally available to meet system demands and similarly, groundwater sustainability impacts have not been modeled beyond this annual production total for average and wet years. Therefore, although select project alternatives are technically capable of exceeding the groundwater modeled annual production totals, any selected project alternative would be operated within the 6,500 AFY and 9,000 AFY caps to maintain consistency with Zone 7’s groundwater management and sustainability objectives. Table 4. Project Alternative Estimated Production Ratesd Basin Condition Scenario Production Metric Project Alternative #1 (Tennis Park) Project Alternative #2 (Tennis and Hansen Parks) Project Alternative #3 (Tennis and Del Prado Parks) Project Alternative #4 (Tennis, Hansen and Del Prado Parks) Drought Year Basin Condition Design Flow Rate (gpm) 3,400 6,800 4,700 8,100 Design Flow Rate (MGD) 4.9 9.8 6.8 11.7 Production Estimate (AFY)c 4,113e 8,227 5,686e 9,800a Average Year Basin Condition Design Flow Rate (gpm) 4,250 8,050 5,850 9,650 Design Flow Rate (MGD) 6.1 11.6 8.4 13.9 Production Estimate (AFY)c 5,142 e 9,739b 7,078b 11,675b Wet Year Basin Condition Design Flow Rate (gpm) 5,100 9,300 7,000 11,200 Design Flow Rate (MGD) 7.3 13.4 10.1 16.1 Production Estimate (AFY)c 6,170 e 11,251b 8,469b 13,550b a Note that impacts to groundwater basin sustainability were not modeled at annual production rates beyond 9,000 AFY in drought year conditions. b Note that impacts to groundwater basin sustainability were not modeled at annual production rates beyond 6,500 AFY in average and wet year conditions. c Production Estimates are based on continuous operation of 18 hours per day, 365 days per year (6,570 hours annually) consistent with Zone 7’s reliability factor operational goal of 75 percent. One AFY = 325,851 gallons. d Production figures are planning-level estimates subject to change as part of Phase II design and construction project development. Actual production may vary due to aquifer conditions, production well drilling contractor performance, long-term groundwater level fluctuations, equipment performance, and gradual well efficiency decline. e Production estimates for Alternatives 1 and 3 do not meet Zone 7’s annual production criteria of 7,000 AFY