Upper Kohanza Lake Dam
Upper Kohanza Lake Dam is an earth dam located in Fairfield County, Connecticut, built in 1866. It carries a High hazard potential classification and has a satisfactory condition assessment.
About Upper Kohanza Lake Dam
The primary purpose of Upper Kohanza Lake Dam is water supply. The dam stores water for municipal, industrial, or agricultural use, helping ensure a reliable supply for the surrounding area. The dam is owned by City Of Danbury (local government). It impounds the Kohanza Brook near Danbury.
The dam stands 30 feet tall and stretches 650 feet across, creates a reservoir covering 29 acres, has a storage capacity of 31 acre-feet, and collects water from a drainage area of 0 square miles. Completed in 1866, the structure is one of the older dams in the region, with over a century and a half 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 satisfactory, indicating no existing or potential dam safety deficiencies are recognized. An emergency action plan is in place for this dam. The most recent inspection on record was 10/22/2024.
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 Connecticut 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 | Connecticut |
| County | Fairfield |
| Nearest City | Danbury |
| River/Stream | Kohanza Brook |
| Coordinates | 41.42286, -73.49002 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 30 ft |
| Dam Height | 30 ft |
| Dam Length | 650 ft |
| Year Completed | 1866 (160 years old) |
Storage & Hydraulics
| NID Storage | 31 acre-ft |
| Normal Storage | 31 acre-ft |
| Surface Area | 29 acres |
| Drainage Area | 0 sq mi |
| Max Discharge | 525 cfs |
Ownership & Safety
| Purpose | Water Supply |
| Owner | City of Danbury |
| Owner Type | Local Government |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 10/22/2024 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | CT00062 |
| Federal ID | CT00062 |
| More Info | State Dam Safety Program |