The recent downgrade in the forecast for the flow of water in the Colorado River should be a death punch to the proposal to build a new pipeline out of Lake Powell. The pipeline was already a major threat to Las Vegas and much of the rest of the Southwest; now the threat risk is heading off the charts.

The proposal would drain 28 billion gallons of water per year from Lake Powell to St. George, Utah, and the surrounding area. That’s a huge amount of water — more than a quarter of what Nevada is allotted annually from Lake Mead (97.8 billion gallons).