The US has lots of land that doesn't require irrigation, but also lots of land that can grow crops if irrigated. Some of that land in California is some of the best farmland in the whole country, growing things that prefer California's Mediterranean climate (similar to parts of Australia's southwest coast).
We have the technology and have had it for a while. But we don't have the laws and habits of dry countries so US water laws are a wasteful mess.
The US has lots of land that doesn't require irrigation, but also lots of land that can grow crops if irrigated. Some of that land in California is some of the best farmland in the whole country, growing things that prefer California's Mediterranean climate (similar to parts of Australia's southwest coast).
We have the technology and have had it for a while. But we don't have the laws and habits of dry countries so US water laws are a wasteful mess.