Rainbow Reservoir Dam
Rainbow Reservoir Dam is an earth dam located in Hartford County, Connecticut, built in 1925. It carries a High hazard potential classification and has a satisfactory condition assessment.
About Rainbow Reservoir Dam
The primary purpose of Rainbow Reservoir Dam is hydroelectric. The dam generates hydroelectric power by channeling water through turbines, converting the energy of flowing water into electricity. The dam is owned by The Farmington River Power Co. (public utility). It impounds the Farmington River near Windsor.
The dam stands 43 feet tall and stretches 1,310 feet across, creates a reservoir covering 234 acres, has a maximum storage capacity of 9,400 acre-feet, and collects water from a drainage area of 588 square miles. Completed in 1925, 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 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 06/07/2024.
At 43 feet, this dam is taller than 89% 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 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 | Hartford |
| Nearest City | Windsor |
| River/Stream | Farmington River |
| Coordinates | 41.91530, -72.69366 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 43 ft |
| Dam Height | 43 ft |
| Dam Length | 1,310 ft |
| Year Completed | 1925 (101 years old) |
Storage & Hydraulics
| NID Storage | 9,400 acre-ft |
| Max Storage | 9,400 acre-ft |
| Normal Storage | 4,800 acre-ft |
| Surface Area | 234 acres |
| Drainage Area | 588 sq mi |
| Max Discharge | 101,000 cfs |
Ownership & Safety
| Purpose | Hydroelectric |
| Owner | The Farmington River Power Co. |
| Owner Type | Public Utility |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 06/07/2024 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | CT00039 |
| Federal ID | CT00039 |
| More Info | State Dam Safety Program |