Fourth “Water With Your Lunch” webinar will be held at noon Wednesday, Aug. 5.

Glenwood Springs, CO — In the fight over Colorado River water, senior water rights dictate which direction the river flows: west on its natural route from the Continental Divide or east through tunnels to the Front Range. On the mainstem of the Colorado, the most heavily diverted of the river’s basins, two historic structures have much to say about providing water security for Western Colorado: the Shoshone Hydropower Plant in Glenwood Canyon and the Grand Valley Diversion Dam in DeBeque Canyon.

The next program in the Colorado River District’s “Water With Your Lunch” webinar series on Zoom will explore the importance of Shoshone and the Grand Valley Roller Dam to all West Slope water users. The webinar is set for noon, Wednesday, Aug. 5.

Panelists for the discussion include Andy Mueller, general manager for the Colorado River District; Mark Harris, manager of the Grand Valley Water Users Association in Grand Junction; Fay Hartman, conservation director, Colorado River Basin Program at American Rivers and Jim Pokrandt, community affairs director of the Colorado River District.

The Shoshone Hydropower Plant holds the oldest, major water right on the mainstem of the river, 1,250 cubic feet a second dated 1902. When river flows ebb after the spring runoff, Shoshone contributes most of the Colorado River’s water in Glenwood Canyon. In turn, those flows support year-round recreation opportunities and the economic benefits that come with them on the mainstem of the Colorado. The Roller Dam is where most of a suite of old water rights called the “Cameo call,” are diverted. Much of this water today provides water for both abundant agriculture and municipal water users along the mainstem of the river.

Both structures command the river, pulling water downstream that might otherwise be diverted to the Front Range through transmountain diversion tunnels. Shoshone and Cameo water rights are filled before these diversions under the prior appropriation system. When either or both rights are calling, junior diverters must cease or replace the water they take out of priority, keeping our West Slope water flowing west and benefitting water users, recreation and ecosystems along the way, from Grand County to the Grand Valley.

“The Colorado River District was created in 1937 to protect West Slope water and keep water on the Western Slope,” says Andy Mueller, General Manager for the Colorado River District. “The Shoshone and Cameo calls play a vital role in that effort to keep our rivers flowing and our crops growing.”