Is It a Bit Early for Flows This Low on the South Fork?

Anglers on the South Fork are noticing a recent round of flow decreases out of Palisades Dam, feeling like flows are now a bit lower than is typical for this time of year. What's the deal?

There are a few factors that could be influencing flows, most of them positive.

1. There's a lot more groundwater return because of the recharge that happened this spring, which means there's less need for reservoir storage water in the system.* Essentially, irrigation needs are being met with lower reservoir outflows thanks to good reach gains in the middle and lower part of the system from recharge and well above-average precipitation south of Willow Creek last summer, fall, and winter.
   

2. For the first time since 2020, all reservoirs in the Upper Snake Basin filled both on paper and physically, allowing all of the reservoirs to be managed to minimize physical storage draft. Outflow at each reservoir is set to meet diversion and a streamflow target and, for example, no water is being sent to American Falls from any of the headwater reservoirs to align physical and paper water (e.g., physical water in Palisades or Island Park that belongs to American Falls users). 
   

3. We are in a temporary mid-summer lull when when hay is being cut and grain is no longer being irrigated. Expect demand to come back up a little in a week or two, which may necessitate increased outflow from Palisades then.

Hopefully, this may benefit the South Fork in the long run--a fuller Palisades at the end of the season creates more flexibility when it comes to winter and spring management in both the South Fork and Henry's Fork watersheds, such as increasing winter flow, continuing the recharge program, etc.

*This is true for both the Henry's Fork and the South Fork, but the affect is more dramatic on the South Fork because the return time of that water to the river is faster and there is more recharge occurring. It's a demonstration of how important the recharge/conjunctive use management strategy is for saving water, maintaining good water quality, and benefitting the ecosystem.