Rapidan is a private hydroelectric dam located in Blue Earth, Minnesota, near the city of Mankato.
Wind
Humidity
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.
Year Completed |
1910 |
Dam Length |
414 |
Dam Height |
73 |
River Or Stream |
Blue Earth |
Primary Dam Type |
Buttress |
Surface Area |
415 |
Hydraulic Height |
62 |
Drainage Area |
2430 |
Nid Storage |
8320 |
Outlet Gates |
Tainter (radial) - 5 |
Hazard Potential |
Significant |
Foundations |
Rock |
Nid Height |
73 |
Blue Earth River Near Rapidan
|
328cfs |
Le Sueur River Near Rapidan
|
179cfs |
Watonwan River Near Garden City
|
82cfs |
Minnesota River At Mankato
|
2870cfs |
Little Cottonwood River Near Courtland
|
33cfs |
Cottonwood River Near New Ulm
|
215cfs |