Henry’s Fork, March 9th, 2024
Rainbow spawning has begun at least on the lower river with most activity occurring under low light conditions. Thus it is vital not to disturb even unoccupied redds.because of the presence of fertilized eggs.
Headlines from Dr. Rob Van Kirk’s Henry’s Fork Drainage SWE Status Report Filed Yesterday3/9
- More precipitation from the Monday–Wednesday event trickled into gages yesterday, keeping the water-year total at 106% of average. SWE dropped to 95% of average.
- Modest precipitation is expected again next Monday–Wednesday.
- At an outflow of 373 cfs, Island Park Reservoir gained 45 ac-ft yesterday and is 91% full, compared with 79% full on average.
- The upper Snake River reservoir system is filling rapidly at 86% full, compared with 76% full on average.
- Today’s precipitation-type take-home: Increasing spring and summer air temperatures have a doubly negative affect on water quality, directly via water temperatures and indirectly via lower water supply.
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Most of the SnoTel stations lost a little snow water equivalent (SWE) yesterday to sublimation, which is typical on cold days following a large snow event. That put net storm-total SWE increase at 1.4 inches, ranging from 0.2 inch at Crab Creek to 2.5 inches at Black Bear. Current SWE is 95% of average: 100% in the Teton headwaters, 97% in Fall River, and 89% in the upper Henry’s Fork. The watershed average currently ranks in the 54th percentile across the last 36 water years.
Rob Van Kirk, Ph.D.
Senior Scientist
P.O. Box 550
Ashton, ID 83420
208-881-3407 CELL