Sylvan Lake Dam is an earth dam located in Lake County, Illinois, built in 1920. It carries a Significant hazard potential classification.
Dam profile
NID height · 15 ft15 ft tall and 120 ft long. 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 Sylvan Lake Dam
The primary purpose of Sylvan Lake Dam is recreation. The dam creates a reservoir used for recreational activities such as fishing, boating, and swimming. The dam is owned by Sylvan Lake Homeowners Association (private). It impounds the Trib Indian Creek near Long Grove.
The dam stands 15 feet tall and stretches 120 feet across, and has a maximum storage capacity of 207 acre-feet. Completed in 1920, the structure is over a century 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 05/11/2022.
Search for dams near your address to see all dams in your area with hazard classifications and safety data.
Location
| State | Illinois |
| County | Lake |
| Nearest City | Long Grove |
| River/Stream | Trib Indian Creek |
| Coordinates | 42.24213, -88.04376 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 15 ft |
| Dam Height | 15 ft |
| Dam Length | 120 ft |
| Year Completed | 1920 (106 years old) |
Storage & Hydraulics
| NID Storage | 207 acre-ft |
| Max Storage | 207 acre-ft |
| Normal Storage | 141 acre-ft |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Recreation |
| Owner | Sylvan Lake Homeowners Association |
| Owner Type | Private |
| Hazard Classification | Significant |
| Condition Assessment | Not assessed |
| Last Inspection | 05/11/2022 |
| Emergency Action Plan | No |
Identifiers
| NID ID | IL00640 |
| Federal ID | IL00640 |
| More Info | State Dam Safety Program |