From email from Reclamation (Dan Crabtree):
Reclamation has begun ramping up releases for the peak flow operation at the Aspinall Unit and Black Canyon. This morning flows increased from Crystal Reservoir by 200 cfs bringing the flow in the Black Canyon and Gunnison Gorge to 2,730 cfs. A 300 cfs increase will be made this afternoon bringing flows in the Black Canyon and Gunnison Gorge to about 3,000 cfs. Flows will continue to increase over the weekend as Crystal Reservoir reaches its spillway crest and begins to spill, probably Saturday afternoon or evening. While spilling, natural fluctuations will be seen in the river system making downstream flows difficult to predict and control. However, below is a table showing estimated flows in the Black Canyon and Gunnison Gorge below the Gunnison Tunnel. These flows should reach a peak of about 6,900 cfs on June 7th and 8th and return to about 3,100 cfs around June 13th. During this operation, combined flows of the mainstem Gunnison, North Fork and other tributaries may result in flows of around 13,000 cfs in the Delta area.