Nevada's climate is arid and semi-arid, with most precipitation occurring as snow in the mountains during the winter months. Major surface flows include the Humboldt River, Truckee River, and Walker River, which are heavily managed and regulated due to their importance for agriculture and urban water supplies. Major reservoirs/dams include Lake Mead, Lake Tahoe, and the Hoover Dam. Nevada's hydrology is heavily influenced by its geology, with a high degree of groundwater storage and limited surface water availability. Snowpack data is critical for water management, with the majority of the state's water supply coming from snowmelt. The Colorado River Basin also plays a significant role in Nevada's water resources, with the state receiving a portion of its allocation from the basin.