Mayfair Reservoir Dam
Mayfair Reservoir Dam is an earth dam located in Cook County, Illinois, built in 1977. It carries a Low hazard potential classification.
About Mayfair Reservoir Dam
The primary purpose of Mayfair Reservoir Dam 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 Metropolitan Water Reclamation District (local government). It impounds the Trib Salt Creek near Westchester.
The dam stands 9 feet tall and stretches 70 feet across, creates a reservoir covering 9 acres, has a maximum storage capacity of 100 acre-feet, and collects water from a drainage area of 1 square miles. Completed in 1977, the structure is 49 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. An emergency action plan is in place for this dam. The most recent inspection on record was 07/22/2025.
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Location
| State | Illinois |
| County | Cook |
| Nearest City | Westchester |
| River/Stream | Trib Salt Creek |
| Coordinates | 41.83869, -87.89351 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 9 ft |
| Dam Height | 9 ft |
| Dam Length | 70 ft |
| Year Completed | 1977 (49 years old) |
Storage & Hydraulics
| NID Storage | 100 acre-ft |
| Max Storage | 100 acre-ft |
| Surface Area | 9 acres |
| Drainage Area | 1 sq mi |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Flood Risk Reduction |
| Owner | METROPOLITAN WATER RECLAMATION DISTRICT |
| Owner Type | Local Government |
| Hazard Classification | Low |
| Condition Assessment | Not Available |
| Last Inspection | 07/22/2025 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | IL55169 |
| Federal ID | IL55169 |
| More Info | State Dam Safety Program |