In reference to this article, scarcity requires society to allocate. Usually markets do a better job than law at allocating efficiently and fairly. Lake Mead could remain full to the brim regardless of pending climate change. The quoted “demand” for 16.6 km3 of Lake Mead water in Southern California and Arizona is not some fixed biological imperative but an artifact of absurdly low water prices. At these low prices, people take 20-minute showers, hose off their driveways, use 5 or more gallons of water to flush their toilets, top off their swimming pools, flood or sprinkler irrigate their lawns, etc. Raise the price, and these uses disappear voluntarily. At the right price, Lake Mead remains full.