Ninth Street Dam in Alpena, Michigan, is a historic gravity dam completed in 1910 primarily for hydroelectric power generation and recreation purposes.
Wind
Humidity
The dam stands at 24 feet in height and spans 503 feet in length, with a storage capacity of 6,000 acre-feet and a drainage area of 1,275 square miles. Situated on the Thunder Bay River, the dam's uncontrolled spillway has a width of 84 feet and can discharge up to 20,600 cubic feet per second.
Managed by the Federal Energy Regulatory Commission, Ninth Street Dam has a high hazard potential due to its age and condition, with a moderate risk assessment rating. Despite its critical importance for water resource management and energy production in the region, the dam's condition assessment is currently listed as "Not Available". Emergency action plans are in place, with the last revision in December 2020, to ensure a prompt response in case of any unforeseen events.
As a key infrastructure for both water resource management and energy production, Ninth Street Dam plays a vital role in the local community. With its historical significance and ongoing operational challenges, maintaining the dam's safety and functionality is crucial for ensuring the sustainable management of the Thunder Bay River watershed and the continued provision of hydroelectric power to the region.
Year Completed |
1910 |
Dam Length |
503 |
Dam Height |
24 |
River Or Stream |
Thunder Bay |
Primary Dam Type |
Gravity |
Surface Area |
700 |
Drainage Area |
1275 |
Nid Storage |
6000 |
Outlet Gates |
Tainter (radial) - 7 |
Hazard Potential |
High |
Foundations |
Rock |
Nid Height |
24 |
Thunder Bay River At Herron Road Near Bolton
|
365cfs |
Au Sable River Near Mc Kinley
|
931cfs |
Au Sable River Near Curtisville
|
937cfs |
Au Sable River Near Au Sable
|
991cfs |
Au Sable River At Mio
|
745cfs |
Au Sable River Near Red Oak
|
633cfs |