After 22 days of Bighorn River flows being above 8,000cfs, river flows are finally on their way down, bringing relief to anglers who have been navigating strong currents, and to downstream landowners who experienced flooding. River flows reached a high discharge of 16,000 cfs during parts of June and July in response to record setting precipitation received throughout June, precipitation that caused inflows to rapidly increase and reservoirs to fill to capacity.
This week dam operators worked to decrease river flows at a rate of about 1,000 cfs a day (broken up into two 500 cfs decreases a day) to evacuate the flood control pool of the reservoir, and return river flows to anticipated summer baseline releases. River flows will decrease to 6,000 cfs by Friday (7/21) afternoon, with more decreases scheduled for next week. The goal is to reach the 2,500 - 5,000 cfs range before months end.
While we have yet to assess the impact this record setting June precipitation had on the river, the BHRA contractors were able to perform bank snorkel surveys within the restored Rattlesnake and Juniper side channels during peak releases. While the high flows made for some challenging conditions, the crew was able to cover the banks quite well and observed ample numbers of rainbow trout fry seeking refuge in the restored habitats!
After summer base flows are achieved, BHRA will be meeting with the Bureau of Reclamation and Montana Fish, Wildlife & Parks to assess the high flow period and monitoring efforts needed moving forward. Currently, the fishing is being reported as great, with dry fly action taking off.