The Holston Watershed covers an area of approximately 4,900 square miles and is located primarily in Tennessee, with small portions in Virginia and North Carolina. The watershed is fed by several major rivers including the North Fork Holston River, South Fork Holston River, and the French Broad River. The Holston Watershed experiences a humid subtropical climate with hot summers and mild winters. The region also receives a significant amount of precipitation throughout the year, with an average annual precipitation of around 46 inches. The snowpack in the watershed varies from year to year, with some winters receiving little snow while others have heavy snowfall. The surface water in the watershed is used for drinking water, irrigation, and recreation. Additionally, there are several large reservoirs in the watershed, including the Cherokee Reservoir and the Douglas Dam. The main constituents of these reservoirs are sediment, nutrients, and organic matter. In recent years, the Holston Watershed has seen an increase in extreme weather events, including heavy rainfall and flooding.