This month’s heavy precipitation that reached record levels in some parts of Idaho turned Thursday’s final meeting of the state Water Supply Committee from talk of drought to concern over flooding.
Mary Mellema of the National Weather Service said the Wood River Valley communities of Ketchum, Hailey and Bellevue are of most concern because of the heavy snowpack and the dramatic growth in the narrow valley over the past dozen years since the last significant spring runoff.
“It will, of course, depend on how the spring progresses,” Mellema told her colleagues on the committee.
Snow accumulation was still heavy in the lower elevations so that the wrong combination of temperatures and other weather conditions could result in a heavy runoff that could force the Big Wood River from its banks. Mellema said all the new construction in the valley has made the potential damage from such a flood unclear.
She also predicted some routine flooding in lower-lying pastures and meadows in the Henry’s Fork and Teton River basins of eastern Idaho because of the extremely heavy snowpack there.
It was the first time flooding has been a topic for the committee that was formed in the late 1980s after drought began to grip the state.
The experts were confident water supplies would be adequate over nearly all of the state earlier this winter. But an extremely wet March more than offset a drier-than-usual February.
“Because February was so dry, this made March a real critical month for us,” Peter Palmer of the Natural Resource Conservation Service said. “It really sealed the water supply. Things look encouraging for most of the state.”
All reservoirs are expected to fill, and the supply of water is expected to be average or above everywhere but the Bear River Basin in southeastern Idaho and the Panhandle.
And if a wet spring holds off the need for early irrigation, agricultural water shortages also could be averted in the Bear River area as well as in the Oakley and Salmon Falls areas.
Department of Water Resources Policy and Planning Administrator Wayne Haas predicted the situation should boost tourism prospects and ease the pressure to accommodate the campaign to restore endangered salmon runs.
“We’re probably a whole lot better off this year than the last seven years,” Haas said, “mainly because the system is filling.”