There are lots of water issues and lots of craziness around water, but as someone interested in sustainable agriculture one drives me particularly nuts. For the most part in the Western United States, water use law is a complex patchwork of competing water rights. While it seems unlikely and even unfair to take water rights away from a farmer or others as they have economic value and would destroy livelihoods, the practice of use it or lose it as enshrined in various states including where I grew up in Washington is counterproductive, even damaging.
Under Use it or Lose it (in Washington State), if a farmer or some other water rights owners don't use their take water for consecutive years they can lose a portion or all of the rights. For example, if during the 5 year period, I don't need more than 20 inches over my property, but my water right is 40 inches (the legal description is in acre feet) I could lose half of my water right. This creates a perverse incentive against taking every possible step to conserve water. A farmer can't just leave the water in the ground or stream for the common good and not risk losing an important asset (good water rights increase the value of farmland many times over acreage without water rights).
The good news is that there is an increasing awareness that this is a problem and that Use it or Lose it is problematic. While I'm happy to write Western congress people on the state and federal level, I can't vote for them. If you can, please write your congress person and find out where they stand on water rights and suggest that it is an important issue to you. Use It or Lose It needs to amended, it is a water issue, it is a food security, it is a common sense issue.