Connecticut Department of Energy & Environmental Protection

Benefits of Dam Removal

The removal of a dam can have numerous advantages, including the reduction of downstream hazard, reduction of the dam owner’s liability, environmental enhancements, and improvements to public safety. If the impounded water is no longer serving any purposes and the dam owners wish to eliminate the liability and risk a dam presents, removal should be evaluated.

 A restored reach of Steele Brook in Watertown following the removal of Heminway Dam
Reduction of Downstream Hazard

The water that's stored behind a dam can become a serious hazard if that dam fails. Dam failure can cause damage to property and infrastructure, economic loss, and harm to downstream inhabitants. When a dam is fully or partially removed, the volume of water that it can impound (and the associated consequences) is reduced.

 

Reduction of Dam Owner's Obligations

When a dam is removed and its downstream risk reduced, the liability of the dam owner will also likely be reduced. Because damage is less likely to occur due to the dam (either upstream or downstream), dam owners may reduce their likelihood of incurring penalties. Also, if the downstream hazard is sufficiently reduced, dam owners may be able to save money on inspections, repairs, and other costs that come with owning a dam.

 

Ecological Enhancements

Dam removal can improve ecological conditions in several ways:

  • Removal of fish barriers improves fish species' ability to migrate, spawn, forage, and avoid predation
  • Re-establishment of natural river flow can increase biodiversity and population density for native species
  • Restoration of natural temperature and oxygen levels can enhance water quality, improving migration and spawning environments for native species
  • Redistribution of sediment that had been trapped behind a dam can re-create natural spawning conditions for fish and aquatic insects

Improvements to Public Safety

Some dams can create a public health hazard without a risk to downstream inhabitants. Low-head dams (sometimes known as "drowning machines") are typically less than 15' high, have relatively low storage, and span the entire width of a river. Low-head dams are not always visible from upstream locations, creating an invisible hazard for swimmers or kayakers. The continuous flow of water and the geometry of the dam create an ongoing recirculating current that can trap people underwater. There have been an estimated 1,400 fatalities from low-head dams in the United States. Removal (or modification) of low-head dams can eliminate the risk that these structures pose.

 

For further information contact the DEEP Dam Safety Regulatory Program at (860) 424-3706 or by email at DEEP.DamSafety@ct.gov

Content last edited August 26, 2025