Most coastal communities in southern California don't even bother to reservoir off their water during rain events, instead letting it drain into the ocean. One major exception being Santa Monica which only uses 40% of it's water from up north unlike other communities which are 100% reliant on it.
Back of the envelope math suggests that based on average rainfall amounts per year a place like Ventura county could be entirely self-sufficient without any desalination plants.
Agriculture can also switch to drip feeding water instead of spraying which cuts usage by 90% without lowering yields.
There's a lot that can be done. We just need the political will to make it happen.
Having extra reservoirs can also support more natural vegetation and potentially actually create conditions for more rainfall further from the coast.
Back of the envelope math suggests that based on average rainfall amounts per year a place like Ventura county could be entirely self-sufficient without any desalination plants.
Agriculture can also switch to drip feeding water instead of spraying which cuts usage by 90% without lowering yields.
There's a lot that can be done. We just need the political will to make it happen.
Having extra reservoirs can also support more natural vegetation and potentially actually create conditions for more rainfall further from the coast.