H.K. Thatcher Lock and Dam
Arkansas — Union County — OUACHITA
Location
| State | Arkansas |
| County | Union |
| River | OUACHITA |
| Coordinates | 33.30665, -92.48316 |
Physical Characteristics
| NID Height | 80 ft |
| Dam Height | — |
| Dam Length | 698 ft |
| NID Storage | 108,000 acre-ft |
| Max Storage | 108,000 acre-ft |
| Surface Area | 12,200 acres |
Safety Classification
| Hazard Potential | Significant |
| Condition Assessment | Not Available |
| EAP Status | Yes |
| Last Inspection | September 4, 2025 |
| Inspection Frequency | 5 |
Dam Information
| Year Completed | 1983 |
| Primary Purpose | Navigation |
| Dam Type | Gravity |
| Owner Type | Federal |
| Owner | USACE - Vicksburg District |
| Other Name | Calion Lock and Dam |
Location Map
About This Dam Record
Dam safety data is maintained by the Army Corps of Engineers National Inventory of Dams (NID). High-hazard dams are those where failure could cause loss of life or major property damage downstream.