Los Angeles imports almost 90% of its’ potable water. Our stormwater pumping and filtration systems are located in the San Fernando Valley. The San Fernando Valley natural Aquifer can hold 1.3 million acre feet of stormwater. There are 500,000 acre feet of aquifer area in the high infiltration area where LADWP has most of its’ pumping stations.
Prior to concreting the City, stormwater percolated into the ground water table and filled much of the aquifer. Since development and directing stormwater into the storm drain system sending our stormwater to the ocean, we have lost our stormwater capture capacity. The basin today is at a low of 87,000 acre feet of stormwater collection. We are currently pumping and filtering from the Aquifer 42,000 acre feet for use as potable water.
The Aquifer is monitored by Regulatory agencies that inform LADWP as to the amount of stormwater they can pump/filter for City use. That amount depends upon how much stormwater is in the Aquifer, we take less than half. Current capacity is at an extremely low level.
Imported water currently costs the City $600 per acre foot; water pumped up/filtered from the Aquifer costs $200 per acre foot. MWD has been increasing our water rates by 5-6% annually, which if continued will mean by 2028 we will be paying from $2800 to $3000 per acre foot of water. This does not include the cost of infrastructure construction that needs to be done in areas where our imported water supply originates.
The San Fernando Valley was developed without some infrastructure, including a complete storm drain system, therefore our streets flood and become hazardous. These flooded streets hold the opportunity to capture this stormwater and recharge our groundwater.