Pearl City Lagoon Dam is an earth dam located in Stephenson County, Illinois, built in 1970. It carries a Significant hazard potential classification.
Dam profile
NID height · 11 ft11 ft tall and 1,700 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 Pearl City Lagoon Dam
Pearl City Lagoon Dam is a dam in Stephenson, Illinois. The dam is owned by Village of Pearl City (local government). It impounds the Yellow Creek - Offstream near Pearl City.
The dam stands 11 feet tall and stretches 1,700 feet across, has a maximum storage capacity of 16 acre-feet, and collects water from a drainage area of 0 square miles. Completed in 1970, 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. An emergency action plan is in place for this dam. The most recent inspection on record was 05/30/2025.
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Location
| State | Illinois |
| County | Stephenson |
| Nearest City | Pearl City |
| River/Stream | Yellow Creek - Offstream |
| Coordinates | 42.27167, -89.82501 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 11 ft |
| Dam Height | 11 ft |
| Dam Length | 1,700 ft |
| Year Completed | 1970 (56 years old) |
Storage & Hydraulics
| NID Storage | 16 acre-ft |
| Max Storage | 16 acre-ft |
| Normal Storage | 12 acre-ft |
| Drainage Area | 0 sq mi |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Other |
| Owner | Village of Pearl City |
| Owner Type | Local Government |
| Hazard Classification | Significant |
| Condition Assessment | Not assessed |
| Last Inspection | 05/30/2025 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | IL50662 |
| Federal ID | IL50662 |
| More Info | State Dam Safety Program |