Henry’s Fork, November 28th, 2023

Headlines from Dr. Rob Van Kirk’s Henry’s Fork Drainage Water Status Report Filed Yesterday

• The Thanksgiving storm stayed to our south, leaving us with only 0.12 inch of precipitation.
• Water-year total precipitation is 99% of average this morning, the first time it has been below average this water year.
• Natural flow has dropped very slowly over the past week and was 92% of average yesterday.
• At an average outflow of 228 cfs, Island Park Reservoir has gained 364 ac-ft/day over the past week and is 85% full, compared to 63% full on average.
• Current reservoir volume is equal to the April-10 average.

Rob Van Kirk, Ph.D.

Senior Scientist

Henry’s Fork Foundation

P.O. Box 550

Ashton, ID 83420

208-881-3407 CELL

[email protected]

• Access remains good on the river below Ashton Dam, however water temps are dropping to a level that impact fish activity. Brown trout are still in a spawning mode, so streamer patterns of choice are still effective, with middle of the day being best time to fish. Same applies to sporadic midge hatches. Presenting nymph patterns of choice can be effective.