Although the Task Force cannot predict the conditions that may favor algae growth in the future, we have determined that both nutrient concentration and algae growth are currently elevated. If we have identified threats to water quality today, and we do nothing to address these impacts, algae blooms could continue or get worse as the Big Sky area grows and our global climate changes.
The Task Force and the Montana Department of Environmental Quality (MT DEQ) diagnosed three streams in the Big Sky area with elevated algae and nutrient levels: the West Fork, Middle Fork of the West Fork, and South Fork of the West Fork through a study that evaluated whether or not streams in the area met state water quality standards. Population growth could worsen the impacts to rivers and streams by increasing the need to treat and dispose of wastewater and expanding the impacts of residential and resort development to streamside and near stream areas.
In addition, the Montana Climate Assessment predicts the annual average daily temperature may warm by 5.6 to 9.8 degrees F across Montana by the end of the century due to anthropogenic climate change. This will warm water temperatures and extend the growing season for algae. Warming temperatures will also affect winter snowpack and midsummer water levels, which further enhances conditions conducive to algae growth.