Regarding California in particular, there is actually plenty of water for the residents. About 80-90% of usable water is used for agriculture, and the majority of that produce is exported from California to other countries and states. For example, all around the capital of Sacramento there are 1000's of acres of rice fields. About half the rice is exported to Asia. Appx 8% or so of California water is used in and around homes, including landscaping.
It takes a gallon of water to grow a single almond, and 95%+ of the worlds almonds come from CA. It takes FIFTY gallons to grow an avocado, and 95% of the WORLD's come from CA also. These are not cherry-picked examples. I could have chosen dozens of other crops.
So, in effect, California's farmers are selling roughly half of its water (in the form of produce) to other states and countries. It's a bit like Saudi Arabia in this sense, but with water instead of oil. Unlike oil, of course, water does replenish, but nevertheless the rate of export is so high that the aquifers are nearly empty now.
Do make sure to take shorter showers though, fellow Californians!
So, in effect, California's farmers are selling roughly half of its water (in the form of produce) to other states and countries. It's a bit like Saudi Arabia in this sense, but with water instead of oil. Unlike oil, of course, water does replenish, but nevertheless the rate of export is so high that the aquifers are nearly empty now.
Do make sure to take shorter showers though, fellow Californians!