Aspinall Unit operations update: Gunnison Tunnel diversions ending for season

From email from Reclamation (Erik Knight):

On Wednesday, November 1st, diversions to the Gunnison Tunnel will end 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 750 cfs. There could be fluctuations in the river throughout the day until the Gunnison Tunnel is completely shut down.

On Thursday and Friday, November 2nd and 3rd, releases from the Aspinall Unit will be reduced to 300 cfs during the day time hours in order to allow for completion of the sonar survey of the Crystal Dam stilling basin. Gunnison River flows will drop down towards 300 cfs during the day while returning to 750 cfs during the non-working hours. After the sonar survey is completed at the end of the day on November 3rd, river flows will return to the current level of 750 cfs.

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 near 850 cfs and flows in the Gunnison River through the Black Canyon are around 750 cfs. After the shutdown of the Gunnison Tunnel and completion of the Crystal stilling basin sonar survey, flows in the Gunnison River through the Black Canyon will return to 750 cfs. Current flow information is obtained from provisional data that may undergo revision subsequent to review.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s