What's even more frustrating is that it's not useful. Here's an article about Utah's water usage WRT alfalfa:

alfalfa and other kinds of hay sucks up 68% of the 5.1 million acre-feet of water diverted every year in Utah

...

amounts to 0.2% of the state’s annual gross domestic product

...

Almost a third of it is exported, mostly to China, taking far too much of our water with it.

So, Utah is using 2/3 of their water to produce 0.2% of their GDP and exports almost a third of it. It's completely stupid...

It's because you have to use your water to keep water rights. Flood irrigating alfalfa is an easy way to use up a lot of water to keep the rights without having to manage more complex farms. The current way that water rights works creates perverse incentives.

I dont understand why we dont ban cattle breeding & importing and be done with it?

Water which evaporates from reservoirs or wetlands isn't "drawn" from the river for human use. So it's about half of water removed for human use