Here’s a message from ODFW: “The USFWS and NOAA have decided to release some water from Bowman Dam next week as a smolt pulse to help steelhead smolts move downstream. We’re trying to let as many constituents know as possible to help minimize inconveniences. The pulse flow will start on April 17 where they will slowly increase the amount of water released throughout the day to ramp up at an appropriate rate. The full 250 cfs pulse will be released all day on the 18th and 19th, and then will slowly be ramped back down to base flow on the 20th. We are uncertain at the moment what base flow will look like at that time since OID has indicated they may start releasing irrigation water on the 17th. Irrigation flows usually average about 200 cfs so the total amount of water could be anywhere from 250 cfs to 450 cfs.”
I would avoid fishing the river during the pulse flows. Given the low amount of water in Prineville Reservoir combined with continued uncertainty about timing and amount of snow melt and runoff into the reservoir, this is a pretty significant event.