Olson Lake Dam
Low HazardNot Available ConditionEmergency Action Plan: No
Location
| State | Illinois |
| County | Winnebago |
| Nearest City | ARGYLE |
| River/Stream | WILLOW CREEK |
| Coordinates | 42.35347, -88.96268 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 24 ft |
| Dam Height | 24 ft |
| Dam Length | 1,130 ft |
| Year Completed | 1991 (35 years old) |
Storage & Hydraulics
| NID Storage | 630 acre-ft |
| Max Storage | 630 acre-ft |
| Normal Storage | 218 acre-ft |
| Surface Area | 12 acres |
| Drainage Area | 9 sq mi |
| Max Discharge | 4,588 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Recreation |
| Owner | ILLINOIS DEPARTMENT OF NATURAL RESOURCES |
| Owner Type | State |
| Hazard Classification | Low |
| Condition Assessment | Not Available |
| Last Inspection | 07/23/2025 |
| Emergency Action Plan | No |