Thorson Group West, located in Hokah, Minnesota, is a state-owned structure designed by USDA NRCS with a primary purpose of flood risk reduction.
Wind
Humidity
Built in 1963, this earth dam stands at 31 feet tall and spans 275 feet in length, with a storage capacity of 20 acre-feet and a drainage area of 0.79 square miles. The dam is situated on the Root River South Fork-TR and falls under the regulatory oversight of the Minnesota Department of Natural Resources - Ecological Water Resources division.
With a significant hazard potential and a satisfactory condition assessment as of May 2015, Thorson Group West is inspected every 4 years to ensure its structural integrity and flood protection capabilities. The dam's spillway, outfitted with uncontrolled outlets, has a width of 50 feet and can handle a maximum discharge of 636 cubic feet per second. Despite its moderate risk rating, the dam has not undergone any significant modifications since its completion and remains a vital component of the flood mitigation infrastructure in Houston County, Minnesota.
Year Completed |
1963 |
Dam Length |
275 |
Dam Height |
29 |
River Or Stream |
ROOT RIVER S FORK-TR |
Primary Dam Type |
Earth |
Surface Area |
0.26 |
Hydraulic Height |
19 |
Drainage Area |
0.79 |
Nid Storage |
20 |
Structural Height |
31 |
Outlet Gates |
Uncontrolled |
Hazard Potential |
Significant |
Foundations |
Unlisted/Unknown |
Nid Height |
31 |
South Fork Root River Near Houston
|
209cfs |
Root River Near Houston
|
472cfs |
Root River Near Pilot Mound
|
303cfs |
Upper Iowa River Near Dorchester
|
147cfs |
Mississippi River At Winona
|
13700cfs |
La Crosse River Near La Crosse
|
348cfs |