Stonehenge #1 Dam
Stonehenge #1 Dam is an earth dam located in Jefferson County, Missouri, built in 1990. It carries a High hazard potential classification and has a satisfactory condition assessment.
About Stonehenge #1 Dam
The primary purpose of Stonehenge #1 Dam is recreation. The dam creates a reservoir used for recreational activities such as fishing, boating, and swimming. The dam is private-owned. It impounds the Trib To Sugar Creek near Arnold.
The dam stands 41 feet tall and stretches 360 feet across, creates a reservoir covering 5 acres, has a maximum storage capacity of 82 acre-feet, and collects water from a drainage area of 0 square miles. Completed in 1990, the structure is 36 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. Its condition is rated satisfactory, indicating no existing or potential dam safety deficiencies are recognized. An emergency action plan is in place for this dam. The most recent inspection on record was 05/05/2022.
At 41 feet, this dam is taller than 88% of dams nationwide.
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 Missouri 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 | Missouri |
| County | Jefferson |
| Nearest City | Arnold |
| River/Stream | Trib To Sugar Creek |
| Coordinates | 38.44625, -90.49787 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 41 ft |
| Dam Height | 41 ft |
| Dam Length | 360 ft |
| Year Completed | 1990 (36 years old) |
Storage & Hydraulics
| NID Storage | 82 acre-ft |
| Max Storage | 82 acre-ft |
| Normal Storage | 64 acre-ft |
| Surface Area | 5 acres |
| Drainage Area | 0 sq mi |
| Max Discharge | 538 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Recreation |
| Owner Type | Private |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 05/05/2022 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | MO31939 |
| Federal ID | MO31939 |
| More Info | State Dam Safety Program |