Lewis

Watershed Hydrology

The Lewis Watershed (HUC 17080002) covers an area of approximately 2,560 square miles in western Montana. The area is known for its diverse hydrology, including high-elevation headwaters, large streams, and reservoirs. The watershed is characterized by a significant snowpack, which provides critical water resources for irrigation and other uses in the region. The melting of the snowpack in the spring and early summer results in high flows in the streams and rivers that feed the region's reservoirs. These reservoirs are an important source of water for both agricultural and urban use. Additionally, the watershed is characterized by a significant amount of forested land, which can affect the hydrology and water quality of the area. In recent years, the region has experienced a trend of warming temperatures, which has led to earlier snowmelt and changes in the timing and amount of streamflow.


Surface Flows

Lewis Watershed

Snowpack Depths

Lewis Watershed

Dams & Reservoirs

Lewis Watershed

Groundwater Levels

Lewis Watershed

Lewis Rivers

Rivers of the Watershed