SGMA which is the state law you're referring to does not restrict groundwater pumping in the way you're imagining it, especially here in SoCal. All of SoCal have managed their water basins quite differently since the 1970's when SoCal realized there was an over pumping issue, imported water combined with recycled water was used then to recharge basins. In some places now only recycled water is used. There will not be an over-pumping issue in OC because OCWD already manages their aquifer by replenishing it with recycled water. However, if the water is purchased from Poseidon at $2800/ACF and that water is then injected into the aquifer, it will significantly bring up the cost of groundwater. That is the current plan because the water is unneeded. The plan is to pay ( and we're using today's Carlsbard plant rate), and pump up to 40 million gallons per day into the aquifer, then take it out and treat it, remove the boron and pump into homes. "SGMA requires governments and water agencies of high and medium priority basins to halt overdraft and bring groundwater basins into balanced levels of pumping and recharge." - water.ca.gov