Willow Park
Willow Park is an earth dam located in Johnson County, Wyoming, built in 1959. It carries a High hazard potential classification.
About Willow Park
The primary purpose of Willow Park is irrigation. The dam stores and diverts water for agricultural irrigation, supporting farming operations in the surrounding area. The dam is owned by Willow Park Res. Co.(bill Dooley-sec.) (private). It impounds the South Fork South Piney Creek near Story.
The dam stands 60 feet tall and stretches 860 feet across, creates a reservoir covering 213 acres, has a maximum storage capacity of 6,469 acre-feet, and collects water from a drainage area of 34 square miles. Completed in 1959, the structure is well into its service life at over 50 years old.
This dam carries a high hazard potential classification, which means that a failure or uncontrolled release of water would likely cause loss of human life. This classification reflects the consequences of failure, not the likelihood — it indicates that people live or work in the area downstream. An emergency action plan is in place for this dam. The most recent inspection on record was 08/02/2022.
At 60 feet, this dam is taller than 95% of all dams in the United States.
Living Downstream
If you live or work downstream of this dam, consider taking these steps: learn your local evacuation routes, check whether your county emergency management office has a dam failure inundation map, and sign up for local emergency alerts. The Wyoming dam safety program can provide more specific information about emergency planning for this structure.
Search for dams near your address to see all dams in your area with hazard classifications and safety data.
Location
| State | Wyoming |
| County | Johnson |
| Nearest City | Story |
| River/Stream | South Fork South Piney Creek |
| Coordinates | 44.46560, -107.03440 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 60 ft |
| Dam Height | 56 ft |
| Dam Length | 860 ft |
| Year Completed | 1959 (67 years old) |
Storage & Hydraulics
| NID Storage | 6,469 acre-ft |
| Max Storage | 6,469 acre-ft |
| Normal Storage | 4,457 acre-ft |
| Surface Area | 213 acres |
| Drainage Area | 34 sq mi |
| Max Discharge | 1,960 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Irrigation |
| Owner | WILLOW PARK RES. CO.(BILL DOOLEY-SEC.) |
| Owner Type | Private |
| Hazard Classification | High |
| Last Inspection | 08/02/2022 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | WY00464 |
| Federal ID | WY00464 |
| More Info | State Dam Safety Program |