Iatt Lake Dam
Iatt Lake Dam is an earth dam located in Grant Parish, Louisiana, built in 1956. It carries a High hazard potential classification and has a satisfactory condition assessment.
About Iatt Lake Dam
The primary purpose of Iatt Lake Dam is recreation. The dam creates a reservoir used for recreational activities such as fishing, boating, and swimming. The dam is owned by State Of Louisiana (state). It impounds the Bayou Rigolette near Colfax.
The dam stands 36 feet tall and stretches 5,310 feet across, creates a reservoir covering 7,100 acres, has a maximum storage capacity of 167,000 acre-feet, and collects water from a drainage area of 242 square miles. Completed in 1956, 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 08/30/2023.
At 36 feet, this dam is taller than 83% 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 Louisiana 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 | Louisiana |
| County | Grant |
| Nearest City | Colfax |
| River/Stream | Bayou Rigolette |
| Coordinates | 31.55232, -92.65849 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 36 ft |
| Dam Height | 36 ft |
| Dam Length | 5,310 ft |
| Year Completed | 1956 (70 years old) |
Storage & Hydraulics
| NID Storage | 167,000 acre-ft |
| Max Storage | 167,000 acre-ft |
| Normal Storage | 31,000 acre-ft |
| Surface Area | 7,100 acres |
| Drainage Area | 242 sq mi |
| Max Discharge | 12,128 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Recreation |
| Owner | State of Louisiana |
| Owner Type | State |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 08/30/2023 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | LA00018 |
| Federal ID | LA00018 |
| More Info | State Dam Safety Program |