The Lower Colorado Watershed (HUC 12090302) covers an area of approximately 60,000 square miles in Arizona, California, Nevada and Mexico. It is home to the Colorado River, which is fed by the Rocky Mountains and provides water to over 40 million people. The watershed experiences a semi-arid climate with high variability in precipitation and temperature. The region's snowpack is critical for water supply and is monitored closely. Surface water in the watershed is managed by several large reservoirs, including Lake Mead and Lake Havasu. These reservoirs also play an important role in generating hydroelectric power. Climate change is expected to have a significant impact on the Lower Colorado Watershed, with increased temperatures and decreased snowpack potentially leading to lower water supplies and increased competition for resources. Overall, the Lower Colorado Watershed is a vital resource for the southwestern United States, and careful management of its water resources is critical for the region's sustainability.