Nystrom Lake Dam is an earth dam located in Henry County, Illinois, built in 1950. It carries a Low hazard potential classification.
Dam profile
NID height · 28 ft28 ft tall and 176 ft long, 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 Nystrom Lake Dam
The primary purpose of Nystrom Lake Dam is recreation. The dam creates a reservoir used for recreational activities such as fishing, boating, and swimming. The dam is owned by Merrill Nystrom (private). It impounds the Trib South Edwards River near Andover-offstrem.
The dam stands 28 feet tall and stretches 176 feet across, and has a maximum storage capacity of 58 acre-feet. Completed in 1950, the structure is well-established, with more than 75 years of service.
This dam has a low hazard potential classification, meaning that failure would cause minimal damage, limited primarily to the dam owner's property, with no expected loss of life. The most recent inspection on record was 05/06/2025.
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Location
| State | Illinois |
| County | Henry |
| Nearest City | Andover-offstrem |
| River/Stream | Trib South Edwards River |
| Coordinates | 41.21833, -90.19365 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 28 ft |
| Dam Height | 28 ft |
| Dam Length | 176 ft |
| Year Completed | 1950 (76 years old) |
Storage & Hydraulics
| NID Storage | 58 acre-ft |
| Max Storage | 58 acre-ft |
| Normal Storage | 40 acre-ft |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Recreation |
| Owner | Merrill Nystrom |
| Owner Type | Private |
| Hazard Classification | Low |
| Condition Assessment | Not assessed |
| Last Inspection | 05/06/2025 |
| Emergency Action Plan | No |
Identifiers
| NID ID | IL01133 |
| Federal ID | IL01133 |
| More Info | State Dam Safety Program |