Lac Emerald Dam
Lac Emerald Dam is a rockfill dam located in St. Francois County, Missouri, built in 1977. It carries a High hazard potential classification.
About Lac Emerald Dam
The primary purpose of Lac Emerald Dam is recreation. The dam creates a reservoir used for recreational activities such as fishing, boating, and swimming. The dam is owned by Terre Du Lac Poa (private). It impounds the Tr Big River near Blackwell.
The dam stands 32 feet tall, creates a reservoir covering 5 acres, has a maximum storage capacity of 86 acre-feet, and collects water from a drainage area of 45 square miles. Completed in 1977, the structure is 49 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.
At 32 feet, this dam is taller than 76% 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 | St. Francois |
| Nearest City | Blackwell |
| River/Stream | Tr Big River |
| Coordinates | 37.88728, -90.59641 |
Physical Characteristics
| Dam Type | Rockfill |
| NID Height | 32 ft |
| Dam Height | 32 ft |
| Year Completed | 1977 (49 years old) |
Storage & Hydraulics
| NID Storage | 86 acre-ft |
| Max Storage | 86 acre-ft |
| Normal Storage | 42 acre-ft |
| Surface Area | 5 acres |
| Drainage Area | 45 sq mi |
Ownership & Safety
| Purpose | Recreation |
| Owner | TERRE DU LAC POA |
| Owner Type | Private |
| Hazard Classification | High |
| Condition Assessment | Not Rated |
| Emergency Action Plan | Not Required |
Identifiers
| NID ID | MO31178 |
| Federal ID | MO31178 |
| More Info | State Dam Safety Program |