[Leftcoast]

I'm not an expert on groundwater policy and aquifer recharge but have been an interested observer for years, mostly for the Central Valley.  In general the valley has been pumping from local aquifers at an unsustainable rate but interest in sustainability and actual practices of groundwater recharge have been growing since the 1970s and accelerated in the 2000s.  The 2014 SGMA (State Groundwater Management Act) is pushing for sustainable groundwater use by 1940.  Lot's of work to do but I'm more optimistic now than I was 20 years ago.  We won't get to where we started but sustainable use is possible.  Remember the central valley was once a sea in geologic time and some of the deep groundwater had millenia to form.  A good water year isn't enough to make up for what was pulled out over the last brief 100 year period of very rapid use.

Having said that this 2022-2023 will be a good water year and the aquifer will "bank" recharge water to help make up for some of the most recent 5 year drought impact.  Not all of it and groundwater recharges slowly and unevenly based on lots of factors but it will help.  Ground water banking, recharge policies, understanding the recharge pathways, and the political will to make this possible will count for more.

Here's some overviews for the interested (some include deeper links to more thorough reports)

2017 Overview from PPIC - Graphs showing impact of pumping in various Central California regions
https://www.ppic.org/publication/groundw...alifornia/

2021 Overview discussing how much groundwater is available each year for recharge and how it is distributed
https://www.ppic.org/publication/groundwater-recharge/

Article on Stanford Study of recharge pathways
https://news.stanford.edu/2021/06/15/fin...-recharge/

One pager showing SGMA timeline
https://lao.ca.gov/sections/resources/wa...ements.pdf

[Leftcoast]

I'm not an expert on groundwater policy and aquifer recharge but have been an interested observer for years, mostly for the Central Valley.  In general the valley has been pumping from local aquifers at an unsustainable rate but interest in sustainability and actual practices of groundwater recharge have been growing since the 1970s and accelerated in the 2000s.  The 2014 SGMA (State Groundwater Management Act) is pushing for sustainable groundwater use by 1940.  Lot's of work to do but I'm more optimistic now than I was 20 years ago.  We won't get to where we started but sustainable use is possible.  Remember the central valley was once a sea in geologic time and some of the deep groundwater had millenia to form.  A good water year isn't enough to make up for what was pulled out over the last brief 100 year period of very rapid use.

Having said that this 2022-2023 will be a good water year and the aquifer will "bank" recharge water to help make up for some of the most recent 5 year drought impact.  Not all of it and groundwater recharges slowly and unevenly based on lots of factors but it will help.  Ground water banking, recharge policies, understanding the recharge pathways, and the political will to make this possible will count for more.

Here's some overviews for the interested (some include deeper links to more thorough reports)

2017 Overview from PPIC - Graphs showing impact of pumping in various Central California regions
https://www.ppic.org/publication/groundw...alifornia/

2021 Overview discussing how much groundwater is available each year for recharge and how it is distributed
https://www.ppic.org/publication/groundwater-recharge/

Article on Stanford Study of recharge pathways
https://news.stanford.edu/2021/06/15/fin...-recharge/

One pager showing SGMA timeline
https://lao.ca.gov/sections/resources/wa...ements.pdf