“Snow Drought” Threatening Western Rivers

An aptly-named “snow drought” has much of the Western United States in its grasp, threatening water supplies in reservoirs, and flows in many of the country’s favorite trout rivers.

A quick glance at the National Weather and Climate Center’s snow-water equivalent map paints a stark picture. While some basins in Idaho, Montana, and Wyoming are above normal, much of Utah, Colorado, and almost all of Oregon are in dire straits.

To compound matters, the current snow-water equivalent map is a bit misleading. While high-elevation basins in Montana, in particular, are near or slightly above normal, lower elevation areas are almost completely devoid of snow. That trend is playing out across much of the West.

Snow in the mountains, but none in the valleys, sounds to many like an ideal winter. But it poses significant risks to the spring water collection season, threatening both reservoir supplies, and river flows. With warmer temperatures, and no snow in mid-to-low elevations, when runoff arrives, more water could end up soaking into the ground instead of making its way into streams and reservoirs.

This could lead to warmer streams and rivers earlier in the year, prompting hoot-owl closures in Montana, and perhaps similar restrictions in other Western states.

It appears that some officials are cautiously optimistic, despite the odd winter conditions. Florence Miller, a Natural Resources Conservation Service hydrologist, said in a press release specifically addressing Montana’s snowpack, that “summer streamflow will depend on how the rest of the winter and spring unfold. For now, the snowpack in the mountains is on track, despite the unseasonable absence of snow in the valleys.”

The snow drought is more pronounced in Colorado and Utah, where many ski resorts have delayed opening, or have only limited terrain available. It’s also prominent in the Pacific Northwest, where they’ve received ample precipitation, but most of it coming as rain instead of snow. Without a thick, healthy snowpack, many rivers throughout Oregon and Washington could face low, warm flows throughout the year, hampering the survival of both steelhead and salmon.

Those same rainstorms also destroyed some of the snowpack in the Pacific Northwest, causing it to melt early. This led to catastrophic flooding near the town of Libby, Montana, and elsewhere a few weeks ago.

Without some good late winter and early spring snow, the Western US could face one of the worst fishing seasons in memory.