Thorne Dam
Thorne Dam is a masonry dam located in Dutchess County, New York, built in 1905. It carries a Significant hazard potential classification and has a fair condition assessment.
About Thorne Dam
The primary purpose of Thorne Dam is recreation. The dam creates a reservoir used for recreational activities such as fishing, boating, and swimming. The dam is owned by Thorne's Dam Llc (private). It impounds the Wassaic Creek near Wassaic.
The dam stands 38 feet tall and stretches 227 feet across, creates a reservoir covering 4 acres, has a maximum storage capacity of 44 acre-feet, and collects water from a drainage area of 21 square miles. Completed in 1905, the structure is over a century 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 03/22/2023.
At 38 feet, this dam is taller than 85% of dams nationwide.
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Location
| State | New York |
| County | Dutchess |
| Nearest City | Wassaic |
| River/Stream | Wassaic Creek |
| Coordinates | 41.81639, -73.58389 |
Physical Characteristics
| Dam Type | Masonry |
| NID Height | 38 ft |
| Dam Height | 38 ft |
| Dam Length | 227 ft |
| Year Completed | 1905 (121 years old) |
Storage & Hydraulics
| NID Storage | 44 acre-ft |
| Max Storage | 44 acre-ft |
| Normal Storage | 35 acre-ft |
| Surface Area | 4 acres |
| Drainage Area | 21 sq mi |
| Max Discharge | 1,790 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Recreation |
| Owner | THORNE'S DAM LLC |
| Owner Type | Private |
| Hazard Classification | Significant |
| Condition Assessment | Fair |
| Last Inspection | 03/22/2023 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | NY00793 |
| Federal ID | NY00793 |
| More Info | State Dam Safety Program |