Alsey Lake Dam is an earth dam located in Scott County, Illinois, built in 1969. It carries a Significant hazard potential classification.
Dam profile
NID height · 27 ft27 ft tall and 290 ft long, taller than 59% 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 Alsey Lake Dam
Alsey Lake Dam is a dam in Scott, Illinois. The dam is owned by Alsey Manufacturing Company (private). It impounds the Trib Little Sandy Creek near Montezuma.
The dam stands 27 feet tall and stretches 290 feet across, and has a maximum storage capacity of 81 acre-feet. Completed in 1969, 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 04/18/2024.
Search for dams near your address to see all dams in your area with hazard classifications and safety data.
Location
| State | Illinois |
| County | Scott |
| Nearest City | Montezuma |
| River/Stream | Trib Little Sandy Creek |
| Coordinates | 39.55546, -90.43001 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 27 ft |
| Dam Height | 27 ft |
| Dam Length | 290 ft |
| Year Completed | 1969 (57 years old) |
Storage & Hydraulics
| NID Storage | 81 acre-ft |
| Max Storage | 81 acre-ft |
| Normal Storage | 54 acre-ft |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Other |
| Owner | Alsey Manufacturing Company |
| Owner Type | Private |
| Hazard Classification | Significant |
| Condition Assessment | Not assessed |
| Last Inspection | 04/18/2024 |
| Emergency Action Plan | No |
Identifiers
| NID ID | IL00811 |
| Federal ID | IL00811 |
| More Info | State Dam Safety Program |