Felchle said the flow reductions will begin at 8:00 p.m. on October 17 when releases from Yellowtail Dam will be gradually reduced to allow evacuation of the Afterbay Reservoir pool. Early on the morning of October 18, releases from the Afterbay Dam will be reduced to 400 cubic feet per second (cfs) and maintained at that rate for approximately 5 hours while the springs are measured. The Afterbay Reservoir will be nearly empty between 7:00 a.m. and noon and the Bighorn River will drop about one and one-half feet during this time. At noon on October 18, plans are to begin gradually increasing releases from the Afterbay Dam to the Bighorn River until a rate of 1,500 cfs is reached. Fishermen and other recreationists planning to use the Bighorn River are cautioned to be aware of the fluctuations in flow that will occur during this time.

According to Felchle, the measurements are an integral part of Reclamation's routine inspection program at Yellowtail Dam. The inspection is conducted every three years after the irrigation season and is timed to minimize impacts to the Bighorn River fishery.