According to Drew Peternell, of Colorado Trout Unlimited's Western Water Project, the Supreme Court laid out a new test for public utilities. In the Pagosa Springs case, the court ruled that the city's claim for water based on a 100-year planning horizon was not reasonable.

“They have to show that claim for water is based on realistic projections for population growth. They can't just pull numbers out the air,” Peternell said.