30 Foot Dam
30 Foot Dam is an arch dam located in Tompkins County, New York, built in 1903. It carries a High hazard potential classification and has a poor condition assessment.
About 30 Foot Dam
The primary purpose of 30 Foot Dam is recreation. The dam creates a reservoir used for recreational activities such as fishing, boating, and swimming. The dam is owned by City Of Ithaca (local government). It impounds the Sixmile Creek near Ithaca.
The dam stands 36 feet tall and stretches 86 feet across, creates a reservoir covering 20 acres, has a maximum storage capacity of 397 acre-feet, and collects water from a drainage area of 47 square miles. Completed in 1903, the structure is over a century old.
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 poor, meaning the dam has recognized safety deficiencies that require remediation to address risks. An emergency action plan is in place for this dam. The most recent inspection on record was 02/27/2025.
At 36 feet, this dam is taller than 83% 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 | Tompkins |
| Nearest City | Ithaca |
| River/Stream | Sixmile Creek |
| Coordinates | 42.42500, -76.47528 |
Physical Characteristics
| Dam Type | Arch |
| NID Height | 36 ft |
| Dam Height | 36 ft |
| Dam Length | 86 ft |
| Year Completed | 1903 (123 years old) |
Storage & Hydraulics
| NID Storage | 397 acre-ft |
| Max Storage | 397 acre-ft |
| Normal Storage | 287 acre-ft |
| Surface Area | 20 acres |
| Drainage Area | 47 sq mi |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Recreation |
| Owner | CITY OF ITHACA |
| Owner Type | Local Government |
| Hazard Classification | High |
| Condition Assessment | Poor |
| Last Inspection | 02/27/2025 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | NY00395 |
| Federal ID | NY00395 |
| More Info | State Dam Safety Program |