Understanding the #GunnisonRiver — Gunnison Basin Roundtable

Map of the Gunnison River drainage basin in Colorado, USA. Made using public domain USGS data. By Shannon1 – Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=69257550

From email from the Gunnison Basin Roudtable (Savannah Nelson):

October 29, 2024

As residents of the Gunnison River Basin, we are privileged to live alongside one of Colorado’s most remarkable natural treasures. The Gunnison River is more than just a waterway—it’s a vital part of our history, our environment, and our daily lives.

The Gunnison River was named after U.S. Army officer and explorer John W. Gunnison, who surveyed the area in the mid-19th century. However, long before Gunnison’s expedition, Indigenous peoples, including the Ute tribes, called this area home. They relied on the river as a source of food, water, and transportation, establishing deep connections with the land and its resources.

The East River Valley, northwest of the historic town of Gothic, home to the Rocky Mountain Biological Laboratory. The mountain with the pointed peak in the distance is Mount Crested Butte. Photo credit: Mark Stone/University of Washington

Our river begins at the confluence of the East River and Taylor River near Almont and flows for about 180 miles until it merges with the Colorado River in Grand Junction. Other tributaries include the North Fork, the Uncompahgre, Cimarron, and Lake Fork. Along its course, the Gunnison carves through some of the most dramatic landscapes in the state, including the striking Black Canyon of the Gunnison—its sheer cliffs dropping over 2,000 feet.

Recreation opportunities are a major piece of local life and tourism; fishing, rafting, swimming, kayaking, and boating are part of the culture surrounding the water.

The Gunnison River is also a lifeline for our local ecosystem. Its waters support a variety of fish species, such as brown and rainbow trout, which are great for anglers, but also contribute to the rich biodiversity of our area.

Sweet corn near Olathe, CO photo via Mark Skalny, The Nature Conservancy.

In addition to the fact that all of us rely on the Gunnison river and its tributaries for drinking water, they play a crucial role in the diverse agricultural activities of the basin. The agricultural uses vary and include a range of cattle and crops, including fruit production and Olathe sweet corn.

Our river is many things: a heritage that we share and a resource we must protect for future generations. To learn more about water and ways to get involved, head to gunnisonriverbasin.org.

Aspinall Unit operations update October 30, 2024: Ramping down Gunnison Tunnel diversions for the season #GunnisonRiver

Gunnison Tunnel via the National Park Service

From email from Reclamation (Erik Knight):

On Wednesday and Thursday, October 30 and 31, diversions to the Gunnison Tunnel will be ramped down for the season. Releases from the Aspinall Unit will be adjusted in coordination with the ramp down schedule for Gunnison Tunnel diversions in order to keep Gunnison River flows near the current level of 370 cfs. There could be fluctuations in the river throughout these days until the Gunnison Tunnel is completely shut down.

On Wednesday, October 30, releases from the Aspinall Unit and Gunnison Tunnel diversions will be reduced by 300 cfs. On Thursday, October 31, releases from the Aspinall Unit and Gunnison Tunnel diversions will be reduced by 650 cfs and Tunnel diversions will be ended until next year.

Flows in the lower Gunnison River are currently above the baseflow target of 1050 cfs. River flows are expected to stay above the baseflow target for the foreseeable future. 

Pursuant to the Aspinall Unit Operations Record of Decision (ROD), the baseflow target in the lower Gunnison River, as measured at the Whitewater gage, is 1050 cfs for October through December.

Currently, diversions into the Gunnison Tunnel are around 980 cfs and flows in the Gunnison River through the Black Canyon are around 370 cfs. After the shutdown of the Gunnison Tunnel, flows in the Gunnison River through the Black Canyon will still be near 370 cfs. Current flow information is obtained from provisional data that may undergo revision subsequent to review.

This scheduled release change is subject to changes in river flows and weather conditions. For questions or concerns regarding these operations contact Erik Knight at (970) 248-0629 or e-mail at eknight@usbr.gov