"Basin States" refers to the states that share a watershed or drainage basin, where water from precipitation flows into a common body of water, such as a river or lake. These states often collaborate on water management and conservation efforts to ensure sustainable use of shared water resources. In the United States, notable examples of Basin States include those within the Colorado River Basin and the Great Lakes Basin. Cooperation among these states is essential for addressing challenges like water scarcity, pollution, and habitat preservation, which can impact both the environment and local communities.