Hidden Valley Lake Dam is an earth dam located in Jefferson County, Missouri, built in 1971. It carries a High hazard potential classification and has a satisfactory condition assessment.
Dam profile
NID height · 36 ft36 ft tall and 330 ft long, taller than 82% 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 Hidden Valley Lake Dam
The primary purpose of Hidden Valley Lake Dam is recreation. The dam creates a reservoir used for recreational activities such as fishing, boating, and swimming. The dam is owned by Hidden Valley Subdivision Trus (private). It impounds the Tr to West Fork Jones Creek near Cedar Hill.
The dam stands 36 feet tall and stretches 330 feet across, creates a reservoir covering 5 acres, has a maximum storage capacity of 84 acre-feet, and collects water from a drainage area of 0 square miles. Completed in 1971, 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. 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 11/10/2022.
At 36 feet, this dam is taller than 82% 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 | Cedar Hill |
| River/Stream | Tr to West Fork Jones Creek |
| Coordinates | 38.28794, -90.69185 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 36 ft |
| Dam Height | 36 ft |
| Dam Length | 330 ft |
| Year Completed | 1971 (55 years old) |
Storage & Hydraulics
| NID Storage | 84 acre-ft |
| Max Storage | 84 acre-ft |
| Normal Storage | 62 acre-ft |
| Surface Area | 5 acres |
| Drainage Area | 0 sq mi |
| Max Discharge | 220 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Recreation |
| Owner | Hidden Valley Subdivision Trus |
| Owner Type | Private |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 11/10/2022 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | MO30418 |
| Federal ID | MO30418 |
| More Info | State Dam Safety Program |