Aspinall Unit Operations update: Turning down to 450 CFS in Black Canyon September 3, 2020 #ColoradoRiver #COriver #aridification

Black Canyon via the National Park Service

From email from Reclamation (Erik Knight):

Releases from the Aspinall Unit will be decreased from 1500 cfs to 1450 cfs on Thursday, September 3rd. Releases are being adjusted to bring flows closer to the baseflow target in the lower Gunnison River. The actual April-July runoff volume for Blue Mesa Reservoir came in at 57% of average.

Flows in the lower Gunnison River are currently above the baseflow target of 890 cfs. River flows are expected to stay at levels above the baseflow target after the release decrease has arrived at the Whitewater gage.

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 890 cfs for September.

Currently, Gunnison Tunnel diversions are 1050 cfs and flows in the Gunnison River through the Black Canyon are around 500 cfs. After this release change Gunnison Tunnel diversions will still be around 1050 cfs and flows in the Gunnison River through the Black Canyon will be around 450 cfs. Current flow information is obtained from provisional data that may undergo revision subsequent to review.

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