Henry’s Fork, December 13th, 2022

Here is some great news from Rob Van Kirk’s Monday, December, 12th Henry’s Fork drainage SWE (snow-water equivalent) report.

Headlines:

• Precipitation over the past three days increased the water-year total to 124% of average and SWE to 145% of average.
• Since outflow from Island Park Reservoir was increased last Thursday, the reservoir has gained 344 ac-ft/day and is 64% full, compared with 65% full on average.

Details:

Precipitation over the past three days ranged from 0.04 inch at Alta to 1.3 inches at Grassy Lake and averaged 0.62 inch for the watershed. That increased water-year precipitation to date to 124% of average and snow water equivalent (SWE) to 145% of average for the date. SWE at all SnoTel stations is in the top one-third of water years since 1989. Generally wet, cold weather is forecast for the foreseeable future.

Since outflow from Island Park Dam was increased to around 195 cfs last Thursday, the reservoir has gained an average of 344 ac-ft/day. Around 75 ac-ft of that has been due to direct precipitation on the reservoir surface. The reservoir is 64% full and within 900 ac-ft of average for the date.

Rob Van Kirk, Ph.D.

Senior Scientist

Henry’s Fork Foundation

P.O. Box 550

Ashton, ID 83420

208-881-3407 CELL

208-652-3568 FAX