Rainbow is a privately owned hydroelectric dam located on the Missouri River in Cascade County, Montana.
Wind
Humidity
Constructed in 1910, this historic dam stands at 44 feet tall and has a hydraulic height of 42 feet. With a storage capacity of 1237 acre-feet and a maximum discharge of 125,000 cubic feet per second, Rainbow plays a crucial role in water resource management in the area.
Managed by the Federal Energy Regulatory Commission, Rainbow's controlled spillway, with a width of 1026 feet, helps regulate water flow and prevent flooding in the region. Despite its high hazard potential, the dam's condition assessment is not available, highlighting the need for ongoing monitoring and maintenance. With an emergency action plan last revised in 2020, Rainbow is equipped to handle potential risks and ensure the safety of surrounding communities.
As a significant piece of infrastructure in the Omaha District, Rainbow serves as a key source of renewable energy and water supply for the local area. Its rich history and engineering design by Charles T. Main make it a fascinating site for water resource and climate enthusiasts interested in the intersection of human ingenuity and environmental stewardship.
Year Completed |
1910 |
Dam Length |
1405 |
Dam Height |
44 |
River Or Stream |
Missouri River |
Primary Dam Type |
Other |
Surface Area |
126 |
Hydraulic Height |
42 |
Drainage Area |
22928 |
Nid Storage |
1237 |
Structural Height |
44 |
Outlet Gates |
Other Controlled - 30, Slide (sluice gate) - 5 |
Hazard Potential |
High |
Foundations |
Rock |
Nid Height |
44 |
Missouri River Near Great Falls Mt
|
3530cfs |
Missouri River Near Ulm Mt
|
3160cfs |
Sun River Near Vaughn Mt
|
2680cfs |
Lake Creek Near Power Mt
|
30cfs |
Muddy Creek At Vaughn Mt
|
86cfs |
Smith River Near Eden Mt
|
119cfs |