Middle Br.
Wind
Humidity
Park River #9, also known as Union Dam, is a local government-owned structure located in Grafton, North Dakota. Built in 1970 by the USDA NRCS, this earth dam stands at 67.5 feet in height with a structural height of 74 feet and a length of 1080 feet. Its primary purpose is flood risk reduction, serving the Middle Branch Park River-TR watershed with a storage capacity of 2466.6 acre-feet.
Managed by the NDSWC, Middle Br. Park River #9 is regulated, permitted, inspected, and enforced by state agencies to ensure its safety and functionality. The dam's spillway, with a width of 250 feet, is of the uncontrolled type, and it holds a hazard potential rating of "Significant." Despite being in moderate risk condition and not having a current condition assessment, the dam continues to play a crucial role in the flood risk mitigation efforts in the region.
With its stone core and soil foundation, Middle Br. Park River #9 is a key feature in the Omaha District's water resource management infrastructure. Although not under the jurisdiction of the USACE, this dam remains a critical component in protecting the surrounding area from potential flood events, showcasing the collaborative efforts between local and federal agencies in safeguarding communities against the impacts of climate change.
Year Completed |
1970 |
Dam Length |
1080 |
Dam Height |
67.5 |
River Or Stream |
MIDDLE BRANCH PARK RIVER-TR |
Primary Dam Type |
Earth |
Surface Area |
9.4 |
Drainage Area |
7.6 |
Nid Storage |
2466.6 |
Structural Height |
74 |
Outlet Gates |
None |
Hazard Potential |
Significant |
Foundations |
Soil |
Nid Height |
74 |
Tongue River At Akra
|
53cfs |
Little South Pembina River Nr Walhalla
|
5cfs |
Pembina River At Walhalla
|
138cfs |
Park River At Grafton
|
26cfs |
Forest River Nr Fordville
|
32cfs |
Forest River At Minto
|
44cfs |