andyt andyt:
The Central Valley isn't a desert.
Regardless, the problem for years has been the issue of growing crops that need significant water in desert areas. The Central Valley isn't the only place in the west that has orchards. There are almond tree orchards in California in some of the naturally drier areas that are ripping out thousands and thousands of their trees because of the huge water requirements per tree. On top of that, they are actually growing rice in one of the California deserts, or trying to at this point.
There is another reason there's a "water shortage", if you read the article.
41% of the water supply in/to California goes to farming. 9% is consumed in urban use. That leaves 50%, which is being smartly used to keep salmon streams and rivers flowing, as well as making sure the wetlands stay wet.
They could readily supply all the water the farms need for this year but then they potentially risk losing even more wetlands than they already have, as well as their salmon spawning grounds.