The hot, dry summer of 2015 provides a useful window into the future of water in northwestern Montana. We experienced low levels of warm water in our streams and lakes. The recent National Climate Assessment – which brought together the nation’s top scientists to project future climate conditions – suggests that this will be our new normal by the 2040s. And that’s the good news scencario, which assumes that people will act to reduce climate change risks. If the world doesn’t soon start to reduce its carbon pollution, then future water quality and quantity will be worse than we’ve ever experienced.
Northwestern Montana, including Glacier National Park, is likely to experience warmer temperatures year round due to a changing climate. Precipitation changes will likely be more of a mixed bag. Overall annual precipitation probably will be about the same or even higher than historical averages. However, winters may see less snow and more rain, and summers are expected to be drier. Spring runoff will peak earlier. Storms are expected to become heavier.This map from the 2014 National Climate Assessment suggests that late-summer stream flows in the Flathead Valley and Glacier National Park will be 30-50 percent lower in the 2040s compared to average conditions between 1916 and 2006. Water temperatures will be warmer, which could lead to algal blooms that erode water quality, invasion of exotic species, and hard times for our native trout.
In 2015, the Whitefish Lake Institute reported that the lake level was the lowest every recorded. If that’s the new normal, it has big implications for boaters, anglers, and the city water supply. Similar stories could be in the future of all of western Montana’s water bodies. Yet while our clean water supplies may diminish, the even scarier truth is that we may be relatively awash in water compared to many other places in the western United States where projections are much more dire.