Trump on water and scarcity

This video clip of Trump talking about water in CA prompted this post.  Trump says that CA has "plenty of water" and ships a lot of water to the sea.

We many have "plenty of water" but water is still scare. We cannot freely use all we want where and when we want it.Water does not miraculously irrigate farms or flow into houses to use. Someone must drill for it, dam it, and construct pipelines to carry it. Heck, we can't even get water we want to drink freely. Why else would anyone pay 7-11 to purchase a bottle of water?

When something is scarce, obtaining more of it creates an opportunity cost. Part of the opportunity cost of diverting more water from rivers to farms and houses is the reduction of fresh water into the sea and the environmental impact of the reduction. I think that the EPA has determined that for at least some rivers any further diversion of water would adversely affect the three-inch fish Trump mentions.