Orl Walcott #1 is an earth dam located in Lyman County, South Dakota, built in 1967. It carries a Significant hazard potential classification.
Dam profile
NID height · 53 ft53 ft tall and 800 ft long, taller than 93% of U.S. dams with a recorded height. Height is drawn to scale against a ten-story building, about 100 ft; the profile is a generic embankment section and the water level is illustrative.
About Orl Walcott #1
The primary purpose of Orl Walcott #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 Dept. of Transportation (state). It impounds the Whiteriver Offstream.
The dam stands 53 feet tall and stretches 800 feet across, creates a reservoir covering 6 acres, and has a maximum storage capacity of 482 acre-feet. Completed in 1967, the structure is well into its service life at over 50 years old.
This dam has a significant hazard potential classification, meaning that a failure could cause significant economic damage — flooding roads, bridges, or property downstream — but is not expected to result in loss of life. The most recent inspection on record was 07/20/2023.
At 53 feet, this dam is taller than 93% of dams nationwide.
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Location
| State | South Dakota |
| County | Lyman |
| Nearest City | None |
| River/Stream | Whiteriver Offstream |
| Coordinates | 43.71965, -99.55006 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 53 ft |
| Dam Height | 53 ft |
| Dam Length | 800 ft |
| Year Completed | 1967 (59 years old) |
Storage & Hydraulics
| NID Storage | 482 acre-ft |
| Max Storage | 482 acre-ft |
| Normal Storage | 102 acre-ft |
| Surface Area | 6 acres |
| Max Discharge | 350 cfs |
Ownership & Safety
| Purpose | Fire Protection, Stock, Or Small Fish Pond |
| Owner | Dept. of Transportation |
| Owner Type | State |
| Hazard Classification | Significant |
| Condition Assessment | Not assessed |
| Last Inspection | 07/20/2023 |
| Emergency Action Plan | Not Required |
Identifiers
| NID ID | SD01152 |
| Federal ID | SD01152 |
| More Info | State Dam Safety Program |