This is my response to the State of California asking for ideas to a call for action to expand water storage capacity and improve groundwater management.
Living in Southwest Riverside California where 60+ percent of the water supplied by the local districts is imported due to an already depleted groundwater environment I see numerous areas where water is wasted.
One being the re-use of reclaimed water. Currently reclaimed water from the Santa Margarita watershed at Temecula is pumped north to the Santa Ana watershed rather than being re-used locally, other than a small portion being used to stabilize Lake Elsinore and watering some parks and schools. Part of this is due to the quantity and quality of the reclaimed water entering the Murrieta Creek a short distance from the ocean. An idea would be to take a portion of this reclaimed water being pumped north out of its current watershed, and introducing it into several of the ephemeral streams during their normally dry periods allowing for further cleansing by a natural process of stream flow, being this amount would be a known quantity it could by adjusted so that a large portion of this new flow would recharge the groundwater basin rather than flow to the ocean. This new flow would intern create new wildlife corridors and increase flow in existing threatened stream beds during times of drought.
Another method to increase groundwater recharge would be to either core holes or create channels in the existing concrete lined flood control channels creating places for additional reclaimed water to be introduced to opportunities to recharge the groundwater basins while still providing for flood control, primarily during dry periods rather than allowing this immense amount of reclaimed water that started out as imported water to be discharged into the ocean used only once
If anyone has an idea they would like to share with the state the can read what is already being proposed and submit their ideas at http://www.opr.ca.gov/s_groundwater.php