In a recently released study, the Bureau of Reclamation predicts increasing temperatures and a declining snowpack for the American River Basin in central California through the end of the 21st century. The report also found an increased variability of fall and winter precipitation, which will amplify the severity of droughts and flooding in the basin.

The American River Basin Study found maximum temperatures are projected to increase throughout the year, with the most significant increase of 7.3 degrees Fahrenheit during the summer months by the end of the 21st century. While projections of average annual precipitation are uncertain, climate projections indicate a change in precipitation timing and variability. Precipitation is projected to be increasingly variable into the future with the timing of the moisture shifting with fall and spring precipitation declining and winter and summer precipitation increasing. In addition, the snowpack will decrease due to warming, moving the peak runoff by more than a month by the mid to late century. The Bureau of Reclamation reports adaptation strategies are already underway in the basin to increase agricultural and urban water use efficiency, water transfers and exchanges within the basin and improving headwaters and forest health. Additionally, it notes new adaptation strategy portfolios were also developed for further evaluation with its partners to maintain a balance between supply and demand. The American River Basin and the area covered by this study consist of 3,600 square miles in central California from the valley through the foothills to the top of the Sierra Nevada. It includes the City of Sacramento and the surrounding area. The Bureau of Reclamation conducted the study in collaboration with water utilities, communities, and other partners in the region. Read more at the U.S. Bureau of Reclamation and Water World.