William O Nannen Pond Dam
William O Nannen Pond Dam is an earth dam located in Cattaraugus County, New York, built in 1964. It carries a Significant hazard potential classification and has a fair condition assessment.
About William O Nannen Pond Dam
The primary purpose of William O Nannen Pond Dam is recreation. The dam creates a reservoir used for recreational activities such as fishing, boating, and swimming. The dam is owned by Michael L. Mead (private). It impounds the Tr-great Valley Creek near Ellicottville.
The dam stands 15 feet tall and stretches 1,230 feet across, creates a reservoir covering 4 acres, has a maximum storage capacity of 36 acre-feet, and collects water from a drainage area of 5 square miles. Completed in 1964, 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. Its condition is rated fair — the dam has minor deficiencies that are being addressed or do not pose an immediate safety threat. An emergency action plan is in place for this dam. The most recent inspection on record was 05/17/2023.
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Location
| State | New York |
| County | Cattaraugus |
| Nearest City | Ellicottville |
| River/Stream | Tr-great Valley Creek |
| Coordinates | 42.28833, -78.66306 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 15 ft |
| Dam Height | 15 ft |
| Dam Length | 1,230 ft |
| Year Completed | 1964 (62 years old) |
Storage & Hydraulics
| NID Storage | 36 acre-ft |
| Max Storage | 36 acre-ft |
| Normal Storage | 20 acre-ft |
| Surface Area | 4 acres |
| Drainage Area | 5 sq mi |
| Max Discharge | 48 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Recreation |
| Owner | Michael L. Mead |
| Owner Type | Private |
| Hazard Classification | Significant |
| Condition Assessment | Fair |
| Last Inspection | 05/17/2023 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | NY00826 |
| Federal ID | NY00826 |
| More Info | State Dam Safety Program |