From The Denver Post (Kirk Mitchell):
Coors had appealed a water court decision that said any water not used by Coors in its augmentation plans must be returned to Clear Creek.
Coors wanted to reuse water after it left its treatment plant and lease water rights for that water to other companies, according to the appeal.
Coors’ water reuse plan was opposed by competing Clear Creek water users including the cities of Denver, Golden, Centennial, Arvada, Thornton, Georgetown and Northglenn along with private companies including the Farmers High Line Canal.
The Supreme Court ruled that Coors could not circumvent a requirement to obtain a new water right by amending its augmentation plans in order to reuse water leaving the plant.
“We further conclude that the diversion of native, tributary water under an augmentation plan does not change its character,” the court ruling says.
Currently a tributary of Clear Creek is diverted to the Coors plant. Water that is not used flows through its wastewater treatment plant and then back into Clear Creek.
Coors believed that it could reuse water leaving its wastewater plant or lease it to other users downstream.
But in 2014, the Colorado State Engineer did not approve a new lease request by Coors to send treated water to Martin Marietta Materials, Inc., according to the lawsuit.
The Supreme Court ruled that Coors’ water rights only allowed a single use of the water diverted by Coors. Any unconsumed water remains waters of the state and must be returned to the stream, the ruling says.