Unionville Old City Lake Dam is an earth dam located in Putnam County, Missouri, built in 1914. It carries a High hazard potential classification.
Dam profile
NID height · 28 ft28 ft tall, taller than 62% 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 Unionville Old City Lake Dam
The primary purpose of Unionville Old City Lake Dam is debris control. The dam is designed to catch sediment, rocks, and debris carried by flowing water — particularly important in areas prone to mudslides or heavy erosion. The dam is owned by Unionville,mo (local government). It impounds the Tr-blackbird Creek near Unionville.
The dam stands 28 feet tall, creates a reservoir covering 12 acres, has a maximum storage capacity of 180 acre-feet, and collects water from a drainage area of 245 square miles. Completed in 1914, the structure is over a century 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.
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 | Putnam |
| Nearest City | Unionville |
| River/Stream | Tr-blackbird Creek |
| Coordinates | 40.47888, -93.02358 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 28 ft |
| Dam Height | 28 ft |
| Year Completed | 1914 (112 years old) |
Storage & Hydraulics
| NID Storage | 180 acre-ft |
| Max Storage | 180 acre-ft |
| Normal Storage | 104 acre-ft |
| Surface Area | 12 acres |
| Drainage Area | 245 sq mi |
Ownership & Safety
| Purpose | Debris Control |
| Owner | Unionville,mo |
| Owner Type | Local Government |
| Hazard Classification | High |
| Condition Assessment | Not assessed |
| Emergency Action Plan | Not Required |
Identifiers
| NID ID | MO10152 |
| Federal ID | MO10152 |
| More Info | State Dam Safety Program |