Alaska's hydrology is characterized by cold and wet conditions, with heavy snowfall in the winter and abundant rainfall in the summer. Major surface flows include the Yukon, Kuskokwim, and Copper rivers, which support commercial and subsistence fishing, transportation, and hydroelectric power generation. Major reservoirs and dams include the Eklutna and Bradley Lake projects. Climate change is affecting Alaska's hydrology, with increased precipitation and glacier melting leading to more frequent flooding and changes in river flow patterns. The state's watersheds are also impacted by mining, oil and gas development, and other human activities. Snowpack levels are closely monitored as they have a significant impact on spring runoff and water availability in the summer.