We received a email from the Henry’s Fork Foundation in regards to the flows below Ashton Dam. Here is the email.
Subject: Ashton Reservoir Drawdown
PacifiCorp has started lowering Ashton Reservoir this morning. If you’re watching the gage below the dam you’ll likely see two increases in river flow of approximately 100 cfs each this morning. The reservoir will lowered to a target of approximately 5147, about 5 feet below the current elevation.
This drawdown is being made in preparation for construction of a new low level diversion tunnel later this year. It is being schedule at this time for the purposes of complying with USFWS consultations relative to the Migratory Bird Treaty Act and in cooperation with the adjacent irrigators on the reservoir who would prefer to not see elevation changes during the growing season.
The drawdown rate will conform to consultation language discussed with IDFG, not more than 100 cfs change in one hour, not to exceed more than 200 cfs change in 24 hours.
So what does this mean for the fishing? I would not be to concerned with these flows upsetting the fishing for very long. Expect it to slow down for a day or two. The fishing will resume as usual after that time. Lots of people have found success using Midges, Rubberlegs, and worms. I would expect the San Jaun Worm fishing to be really good with these increased flows.