Willow Lake Dam
High HazardNot Available ConditionEmergency Action Plan: Yes
Location
| State | Illinois |
| County | Stephenson |
| Nearest City | FREEPORT |
| River/Stream | TRIB PECATONICA RIVER |
| Coordinates | 42.33181, -89.63911 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 25 ft |
| Dam Height | 25 ft |
| Dam Length | 590 ft |
| Year Completed | 1974 (52 years old) |
Storage & Hydraulics
| NID Storage | 299 acre-ft |
| Max Storage | 299 acre-ft |
| Normal Storage | 165 acre-ft |
| Surface Area | 23 acres |
| Drainage Area | 0 sq mi |
| Max Discharge | 2,313 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Other |
| Owner | WILLOW LAKE ASSOCIATION |
| Owner Type | Private |
| Hazard Classification | High |
| Condition Assessment | Not Available |
| Last Inspection | 08/13/2025 |
| Emergency Action Plan | Yes |