Why is Island Park Reservoir getting so low? Simply put, this has been an exceptionally low-water year. There isn’t enough natural flow to meet all of the basin’s needs without drawing down reservoirs. Water managers are working together to deliver water that is legally owed downstream while preserving as much as possible for next year. What should anglers expect below Island Park Dam? As Island Park Reservoir drops too low for the hydropower plant to operate, all outflow will shift to the dam gates. The river below the dam will become more turbid and off-color, and anglers may see plant material, algae mats, suspended sediment, and even some fish moving out of the reservoir. The important difference from last year is duration: these conditions are expected to last only a few weeks, compared with nearly 12 weeks of elevated turbidity from July into October 2025. Is coordinated water management making a difference? A significant one. In a water year this poor, Island Park Reservoir would historically be expected to finish essentially empty. Instead, years of precise water management and collaboration through the Drought Management Planning Committee are allowing the Henry’s Fork reservoirs to retain substantially more water than the Upper Snake system overall— about 33% full