The River Otra Basin is a significant hydrological area located in southern Norway. It encompasses the region surrounding the Otra River, which flows through the municipalities of Evje og Hornnes and Bygland. The basin is characterized by its diverse ecosystems, including forests, wetlands, and agricultural land, supporting various wildlife and plant species. The Otra River itself is known for its clear waters and is popular for recreational activities such as fishing and kayaking. The basin plays a crucial role in local water management and contributes to the region's economy through tourism and natural resource utilization.