Flood control measures in place before melting snows

Washington—The Bureau of Reclamation and U.S. Army Corps of Engineers is releasing more and more water each day down the Boise River and Snake River basins as part of their flood risk-management operations.

At the first of March, the Boise River was running just 280 cubic feet per second, The Bureau has increased that flow to 1,780 in daily 500-CFS increments.

“We’re planning to increase the discharges,” said Michael Coffey of the Bureau of Reclamation.  “I don’t know if it’s a concern as much as it is an awareness for people.”

Historic February snowfall has prompted flood control measures across the state. Precipitation totals for February were as much as 310 percent of normal, according to the National Weather Service. The releases are needed to help reduce the risk of flooding later in the spring, which can happen with warmer days and seasonal precipitation.

Eastern Idaho’s Upper Snake River reservoirs are at 87 percent of capacity and that's a concern because the region is weeks ahead of the annual spring thaw. There’s so much water in state reservoirs that the Bureau of Reclamation is starting to make releases from upstream dams like Palisades Reservoir for flood control.

Southeast Idaho reservoirs are getting full, and forecasters are counting on a minimum of 105 percent of normal runoff below the Heise gauge just downstream from Palisades Reservoir.

The snowpack for the Snake River Basin above American Falls Reservoir stands at 119 percent of the 30-year average through March 19.

Idaho farmers along the Snake River Plain can expect another excellent irrigation year. There is so much water in reservoirs right now that this year could surpass the massive 2017 water year that saw widespread flooding.

That said, Idaho Water Resources Board says that irrigators on all basins can expect a full allotment of water. That's a staggering amount of water because Gem State Farmers irrigate more than 55 million acres.

Eastern Idaho was drier last summer and the snow will melt deep into the parched water table. Daytime highs have started reaching into the low 50s while nighttime lows have stayed freezing, that means gradual snow-melt and reduce the risk of flooding if the trend continues.

Upper Snake River canal companies have started injecting surplus river water into the Snake River Aquifer in a managed aquifer recharge again this year.

The Aberdeen-Springfield Canal Co.started recharging water in February. The People’s Canal in the Pingree area and the Snake River Valley Irrigation District near Blackfoot also started recharging surplus water.

The Bureau of Reclamation expects to keep releasing water from the Milner Dam, about 20 miles up-stream from Shoshone Falls. Ensuring spectacular streamflows over the 212-foot waterfall, well into May.