Helderberg Lake Dam
Helderberg Lake Dam is a concrete dam located in Albany County, New York, built in 1944. It carries a High hazard potential classification and has a fair condition assessment.
About Helderberg Lake Dam
The primary purpose of Helderberg Lake Dam is recreation. The dam creates a reservoir used for recreational activities such as fishing, boating, and swimming. The dam is owned by Helderberg Lake Association (private). It impounds the Tr-onesquethaw Creek near Clarksville.
The dam stands 35 feet tall and stretches 340 feet across, creates a reservoir covering 27 acres, has a maximum storage capacity of 330 acre-feet, and collects water from a drainage area of 2 square miles. Completed in 1944, the structure is well-established, with more than 75 years of service.
This dam carries a high hazard potential classification, which means that a failure or uncontrolled release of water would likely cause loss of human life. This classification reflects the consequences of failure, not the likelihood — it indicates that people live or work in the area downstream. 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 04/09/2024.
At 35 feet, this dam is taller than 82% of dams nationwide.
Living Downstream
If you live or work downstream of this dam, consider taking these steps: learn your local evacuation routes, check whether your county emergency management office has a dam failure inundation map, and sign up for local emergency alerts. The New York dam safety program can provide more specific information about emergency planning for this structure.
Search for dams near your address to see all dams in your area with hazard classifications and safety data.
Location
| State | New York |
| County | Albany |
| Nearest City | Clarksville |
| River/Stream | Tr-onesquethaw Creek |
| Coordinates | 42.59722, -74.01250 |
Physical Characteristics
| Dam Type | Concrete |
| NID Height | 35 ft |
| Dam Height | 35 ft |
| Dam Length | 340 ft |
| Year Completed | 1944 (82 years old) |
Storage & Hydraulics
| NID Storage | 330 acre-ft |
| Max Storage | 330 acre-ft |
| Normal Storage | 172 acre-ft |
| Surface Area | 27 acres |
| Drainage Area | 2 sq mi |
| Max Discharge | 2,100 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Recreation |
| Owner | HELDERBERG LAKE ASSOCIATION |
| Owner Type | Private |
| Hazard Classification | High |
| Condition Assessment | Fair |
| Last Inspection | 04/09/2024 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | NY00276 |
| Federal ID | NY00276 |
| More Info | State Dam Safety Program |