The River Rundown: Your FAQs from June 2025
“It feels like July!” was a common sentiment shared around the watershed last month. Anglers enjoyed Brown Drakes on the Ranch three weeks earlier than usual, basked in 70°F more days than not, and endured high outflows from Island Park Dam that are more typical for mid-July. Some of these changes were welcome… others, not so much. Below, we answer your most Frequently Asked Questions from June. FAQ: Outflow from Island Park Dam peaked around 1,600 cfs. Why so high, so early? Warm and dry conditions increased irrigation demand in the lower watershed 10% higher than average. To meet irrigation demand and maintain fish habitat around St. Anthony, water managers rely on water delivered from Island Park Reservoir and on natural streamflow Natural streamflow comes from mountain snow and groundwater springs—but is 38% below average. Therefore, Island Park Reservoir has to work that much harder to make up the difference. With so little water in the system, high outflow in Island Park is needed just to keep the river wet 60 miles downstream. FAQ: What’s up with the constant flow changes at the dam? In wetter years prior to the year 2000, there was enough water to go around—so managers
