California and other states vie for the water in the Colorado River, but Colorado is not one of them.
Agreements were made years ago, and as I understand it California abides by them. So do the other states.
This taxes the water supply remaining in the Colorado river. That is a concern. I’m not sure what the current situation is, but California having as much frontage on the river as anyone, has a right to stake claims to the water just like others do. Nothing evil about it.
California has the most frontage to the Pacific Ocean, which makes what they're doing completely evil.