Upper Maple River Dam, Steele County, ND

The Upper Maple River Dam culminates almost 20 years of planning and preparation. It replaced the smaller Sussex Dam, located about two miles upstream. This dam will reduce flood damages over more than 20,000 acres in portions of Steele, Barnes and Cass counties where the river can widen to two miles during floods. The dam protects local farmland in the area prone to frequent inundation and infrastructure immediately downstream of the dam. The dam has a flood peak reduction of 86 percent in a 100-year, 24-hour rainfall and 58 percent in a 100-year snowmelt. The floodplain protected by the project is 22,365 acres.

The Upper Maple River Dam is a dry dam, meaning that it only holds water during floods, allowing farmers to continue using pasture and cropland behind the dam.


Cost of construction: $5.67 million
Total cost:$9.2 million

North Dakota State Water Commission: $4.37 million
Red River Joint Water Resource District: $2.65 million
Cass County Flood Sales Tax: $715,000
Local (assessments): $860,000

Started: April 2015
Completed: November 2015

Reservoir capacity at the spillway: 5,325 acre-feet
Reservoir capacity at the top of the dam: 9,950 acre-feet
Pool area at the spillway: 600 acres
Pool area at the top of the dam: 925 acres
Watershed area: 58 square miles
Maximum height: 35 feet
Width at the top of the dam: 20 feet
Embankment side slopes (H:V): 3:1
Length of embankment: 4,400 feet
Embankment volume: 150,000 cubic yards
Concrete volume: 1,550 cubic yards

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