California has a management strategy to recharge aquifers during flood events like this one. It's called ag-MAR or flood-MAR.

Basically, the idea is to intentionally flood areas like orchards or fields during the winter, allowing floodwaters to soak into the ground and down to the aquifer. There are things you have to be careful about when doing this (nitrate contamination of groundwater, for instance) but it's a promising approach.