Island Lake 22b is a dam located in Lyon County, Minnesota, built in 1999. It carries a Low hazard potential classification and has a satisfactory condition assessment.
Dam profile
NID height · 33 ft33 ft tall and 730 ft long, taller than 76% 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 Island Lake 22b
The primary purpose of Island Lake 22b is flood risk reduction. The dam is designed to control downstream flooding by temporarily storing excess water during storms and releasing it at a controlled rate. The dam is owned by County of Lyon (local government). It impounds the Threemile Creek.
The dam stands 33 feet tall and stretches 730 feet across, has a maximum storage capacity of 530 acre-feet, and collects water from a drainage area of 21 square miles. Completed in 1999, the structure is 27 years old.
This dam has a low hazard potential classification, meaning that failure would cause minimal damage, limited primarily to the dam owner's property, with no expected loss of life. Its condition is rated satisfactory, indicating no existing or potential dam safety deficiencies are recognized. The most recent inspection on record was 09/09/2022.
At 33 feet, this dam is taller than 76% of dams nationwide.
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Location
| State | Minnesota |
| County | Lyon |
| Nearest City | None |
| River/Stream | Threemile Creek |
| Coordinates | 44.40940, -95.99885 |
Physical Characteristics
| NID Height | 33 ft |
| Dam Height | 33 ft |
| Dam Length | 730 ft |
| Year Completed | 1999 (27 years old) |
Storage & Hydraulics
| NID Storage | 530 acre-ft |
| Max Storage | 530 acre-ft |
| Normal Storage | 12 acre-ft |
| Drainage Area | 21 sq mi |
Ownership & Safety
| Purpose | Flood Risk Reduction |
| Owner | County of Lyon |
| Owner Type | Local Government |
| Hazard Classification | Low |
| Condition Assessment | Satisfactory |
| Last Inspection | 09/09/2022 |
| Emergency Action Plan | Not Required |
Identifiers
| NID ID | MN01731 |
| Federal ID | MN01731 |
| More Info | State Dam Safety Program |