Rock Cowan No. 1 is an earth dam located in Dewey County, South Dakota, built in 1950. It carries a Low hazard potential classification.
Dam profile
NID height · 26 ft26 ft tall and 660 ft long, taller than 55% of U.S. dams with a recorded height. Height is drawn to scale against a two-story house, about 25 ft; the profile is a generic embankment section and the water level is illustrative.
About Rock Cowan No. 1
The primary purpose of Rock Cowan No. 1 is fire protection, stock, or small fish pond. The dam maintains a small impoundment used for fire suppression, livestock watering, or as a fish pond. The dam is owned by Rock Cowan (private). It impounds the Tr Moreau.
The dam stands 26 feet tall and stretches 660 feet across, and has a maximum storage capacity of 200 acre-feet. Completed in 1950, the structure is well-established, with more than 75 years of service.
This dam has a low hazard potential classification, meaning that failure would cause minimal damage, limited primarily to the dam owner's property, with no expected loss of life.
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Location
| State | South Dakota |
| County | Dewey |
| Nearest City | None |
| River/Stream | Tr Moreau |
| Coordinates | 45.07666, -101.43166 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 26 ft |
| Dam Height | 26 ft |
| Dam Length | 660 ft |
| Year Completed | 1950 (76 years old) |
Storage & Hydraulics
| NID Storage | 200 acre-ft |
| Max Storage | 200 acre-ft |
| Normal Storage | 120 acre-ft |
| Max Discharge | 6,000 cfs |
Ownership & Safety
| Purpose | Fire Protection, Stock, Or Small Fish Pond |
| Owner | Rock Cowan |
| Owner Type | Private |
| Hazard Classification | Low |
| Condition Assessment | Not assessed |
| Emergency Action Plan | Not Required |
Identifiers
| NID ID | SD00242 |
| Federal ID | SD00242 |
| More Info | State Dam Safety Program |