National Petroleum Chemical Plant Lake Dam
National Petroleum Chemical Plant Lake Dam is an earth dam located in Douglas County, Illinois, built in 1952. It carries a Significant hazard potential classification.
About National Petroleum Chemical Plant Lake Dam
The primary purpose of National Petroleum Chemical Plant Lake Dam is water supply. The dam stores water for municipal, industrial, or agricultural use, helping ensure a reliable supply for the surrounding area. The dam is owned by U. S. Industrial Chemical Company (private). It impounds the Kaskaskia River-offstream near Staunton-offstream.
The dam stands 21 feet tall and stretches 2,500 feet across, and has a maximum storage capacity of 367 acre-feet. Completed in 1952, the structure is well into its service life at over 50 years old.
This dam has a significant hazard potential classification, meaning that a failure could cause significant economic damage — flooding roads, bridges, or property downstream — but is not expected to result in loss of life. The most recent inspection on record was 06/11/2025.
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Location
| State | Illinois |
| County | Douglas |
| Nearest City | Staunton-offstream |
| River/Stream | Kaskaskia River-offstream |
| Coordinates | 39.80111, -88.36342 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 21 ft |
| Dam Height | 21 ft |
| Dam Length | 2,500 ft |
| Year Completed | 1952 (74 years old) |
Storage & Hydraulics
| NID Storage | 367 acre-ft |
| Max Storage | 367 acre-ft |
| Normal Storage | 350 acre-ft |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Water Supply |
| Owner | U. S. INDUSTRIAL CHEMICAL COMPANY |
| Owner Type | Private |
| Hazard Classification | Significant |
| Condition Assessment | Not Available |
| Last Inspection | 06/11/2025 |
| Emergency Action Plan | No |
Identifiers
| NID ID | IL00738 |
| Federal ID | IL00738 |
| More Info | State Dam Safety Program |