Map of All 1,289 Connecticut Dams
Connecticut has 1,289 dams in the National Inventory of Dams — and 276 are classified as high hazard (21% of the state’s total), meaning failure would likely cause loss of life. 17 Connecticut dams are both high-hazard and in poor or unsatisfactory condition.
Use the interactive Connecticut dams map below to explore every dam in the state, color-coded by hazard level. Click any dam for its condition assessment, last inspection date, and Emergency Action Plan status. Or view the full US Dams interactive map to compare Connecticut to every other state.
Hazard
Condition
Purpose
Connecticut Dams by the Numbers
- 1,289 total dams in Connecticut
- 276 high hazard — failure would likely cause loss of life
- 952 significant hazard
- 61 low hazard
- 128 in poor or unsatisfactory condition (124 poor, 4 unsatisfactory)
- 17 Connecticut dams are both high-hazard AND in poor/unsatisfactory condition
Data source: US Army Corps of Engineers, National Inventory of Dams (NID).
The Tallest Dams in Connecticut
The tallest dam in Connecticut is Colebrook River Dam at 223 feet, completed in 1969. The 10 tallest Connecticut dams from the National Inventory of Dams:
| Dam | Height | Year | Primary Purpose | Condition | County |
|---|---|---|---|---|---|
| Colebrook River Dam | 223 ft | 1969 | Flood Risk Reduction | Not Available | Litchfield |
| Mad River Flood Control Dam | 178 ft | 1963 | Flood Risk Reduction | Satisfactory | Litchfield |
| Nepaug Dam | 156 ft | 1918 | Water Supply | Fair | Litchfield |
| Shepaug | 138 ft | 1955 | Hydroelectric | Satisfactory | New Haven |
| Saville Dam | 137 ft | 1940 | Water Supply | Satisfactory | Litchfield |
| Thomaston Dam | 137 ft | 1960 | Flood Risk Reduction | Not Available | Litchfield |
| Black Rock Dam | 130 ft | 1971 | Flood Risk Reduction | Not Available | Litchfield |
| Samuel P. Senior Dam | 130 ft | 1941 | Water Supply | Satisfactory | Fairfield |
| Goodwin | 125 ft | 1960 | Hydroelectric | Satisfactory | Hartford |
| Easton Reservoir Dam | 123 ft | 1926 | Water Supply | Fair | Fairfield |
High-Hazard Connecticut Dams in Poor Condition
The most concerning dams are those classified as high-hazard that also carry a Poor or Unsatisfactory condition rating — 17 dams in Connecticut. Notable examples:
- Crystal Lake Dam (50 ft, Middlesex County) — Recreation, Poor condition
- Hartford Reservoir #1 Dam (46 ft, Hartford County) — Water Supply, Poor condition
- Lake Whitney Dam (44 ft, New Haven County) — Water Supply, Poor condition
- Great Hill Reservior Dam (41 ft, New Haven County) — Recreation, Poor condition
- Peat Swamp Reservoir Dam (41 ft, New Haven County) — Water Supply, Poor condition
Filter the interactive US Dams map by hazard and condition to see all of them on one view.
Dam Safety in Connecticut
Dam safety in Connecticut is overseen by the state dam safety program, in coordination with federal regulators: the US Army Corps of Engineers, the Bureau of Reclamation (for federal water projects), the Tennessee Valley Authority where applicable, and the Federal Energy Regulatory Commission (FERC) for licensed hydropower dams. Emergency Action Plans are typically required for high-hazard dams under state regulations.
Frequently Asked Questions
How many dams are in Connecticut?
Connecticut has 1,289 dams in the National Inventory of Dams tracked by the US Army Corps of Engineers: 276 high hazard, 952 significant hazard, and 61 low hazard.
What is the tallest dam in Connecticut?
The tallest dam in Connecticut is Colebrook River Dam at 223 feet, completed in 1969. It is primarily a flood risk reduction structure.
How many Connecticut dams are in poor condition?
128 Connecticut dams are currently rated as being in Poor or Unsatisfactory condition. Of those, 17 are also classified as high-hazard — meaning failure would likely cause loss of life.
