Griswold No. 1
Griswold No. 1 is an earth dam located in Niobrara County, Wyoming, built in 1954. It carries a Low hazard potential classification and has a poor condition assessment.
About Griswold No. 1
The primary purpose of Griswold 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 Tetrad Corporation (private). It impounds the Griswold Draw near Edgemont, Sd.
The dam stands 25 feet tall and stretches 645 feet across, creates a reservoir covering 9 acres, and has a maximum storage capacity of 133 acre-feet. Completed in 1954, the structure is well into its service life at over 50 years old.
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. Its condition is rated poor, meaning the dam has recognized safety deficiencies that require remediation to address risks. The most recent inspection on record was 09/28/2023.
Search for dams near your address to see all dams in your area with hazard classifications and safety data.
Location
| State | Wyoming |
| County | Niobrara |
| Nearest City | Edgemont, Sd |
| River/Stream | Griswold Draw |
| Coordinates | 43.21278, -104.15694 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 25 ft |
| Dam Height | 25 ft |
| Dam Length | 645 ft |
| Year Completed | 1954 (72 years old) |
Storage & Hydraulics
| NID Storage | 133 acre-ft |
| Max Storage | 133 acre-ft |
| Normal Storage | 73 acre-ft |
| Surface Area | 9 acres |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Fire Protection, Stock, Or Small Fish Pond |
| Owner | TETRAD CORPORATION |
| Owner Type | Private |
| Hazard Classification | Low |
| Condition Assessment | Poor |
| Last Inspection | 09/28/2023 |
| Emergency Action Plan | Not Required |
Identifiers
| NID ID | WY00755 |
| Federal ID | WY00755 |
| More Info | State Dam Safety Program |