From email from Reclamation (Erik Knight):
Releases from the Aspinall Unit will be decreased by 75 cfs on Sunday, September 9th. Releases are being decreased in order to bring flows in the lower Gunnison River closer to the baseflow target while conserving storage in Blue Mesa Reservoir. The actual April-July runoff volume for Blue Mesa Reservoir was 237,500 AF of inflow, which is 35% of average.
Flows in the lower Gunnison River are currently above the baseflow target of 890 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 890 cfs for September.
Currently, diversions into the Gunnison Tunnel are 1000 cfs and flows in the Gunnison River through the Black Canyon are around 575 cfs. After this release change Gunnison Tunnel diversions will still be 1000 cfs and flows in the Gunnison River through the Black Canyon will be around 500 cfs.