Rapidan is a private hydroelectric dam located in Blue Earth, Minnesota, near the city of Mankato. Built in 1910, this buttress dam stands at a height of 73 feet and has a maximum storage capacity of 8,320 acre-feet. The dam spans 414 feet in length and serves the primary purpose of generating hydroelectric power from the Blue Earth River.

Managed by the Federal Energy Regulatory Commission, Rapidan is a significant structure with a controlled spillway and five Tainter radial gates for water release. With a hazard potential rated as significant and a very high risk assessment level, the dam is inspected every three years to ensure its safety and functionality. The surrounding area has a drainage area of 2,430 square miles and a maximum discharge capacity of 51,700 cubic feet per second, making it a crucial part of the local water resource infrastructure.

Despite its age, Rapidan continues to play a vital role in water management and electricity generation in the region. With its impressive engineering design and historical significance, this dam serves as a reminder of the importance of sustainable water resource management and climate resilience efforts in the face of changing environmental conditions.