Dam Removal

Dam Removal

CONTENT

There are more than 90,000 dams in the United States. Many of these dams continue to provide safe and reliable social and economic benefits, such as water supply, flood control, hydropower, and recreation. However, thousands of dams no longer serve a viable purpose or provide significant benefits. Many have exceeded the average life expectancy of a dam, become structurally unsound and unsafe to the public, and require costly repairs to bring them into compliance with state or federal safety regulations. All repairs are the responsibility of the dam owner. The cost to repair and rehabilitate a dam can exceed the owner’s financial abilities. Many dam owners choose to remove their dams to eliminate ongoing maintenance costs and public safety concerns and reduce financial and legal liability.

Considerations for Removal - Impacts

Before a dam owner can consider the removal of their dam, they must first evaluate the feasibility of all possible alternatives, such as:

  • Altering the dam’s operation (e.g., reducing reservoir levels)
  • Rehabilitating or repairing the dam
  • Removing the dam

When removing a dam, consideration must be given to identifying and assessing the diverse changes created by the dam’s removal. These significant changes may vary in importance to the dam owner(s) vs. other parties who may have very different vested interests, i.e., the general public, community leaders, state fish and wildlife departments, state historic preservation offices, environmental restoration organizations, abutting property owners upstream and downstream, etc.

Consideration must be given to the following:

  • Public Safety – potential increased flood risk downstream; removal of dam failure hazard
  • Fish Passage – greater fish diversity; invasive species
  • Stream Restoration – improved aquatic habitat
  • Sediment Management – costly removal if contaminated
  • Recreation – navigable waterways; shoreline revitalization
  • Property Value – loss of lakefront properties
  • Historical Significance
  • Existing Infrastructure – groundwater availability; loss of reservoir/changes in river flow can cause adverse effects on bridges, submerged utility lines, etc.

Considerations for Removal - Costs

The financial cost associated with the removal of a dam is case-specific and depends on numerous variables, some of which are listed below:

  • Dam’s composition – concrete, masonry, timber, earthen
  • Dam’s material condition
  • Dam’s size – height, length
  • Good or limited site access
  • Sediment issues – contamination, removal, disposal
  • Proper removal and disposal of materials
  • Restoration of site
  • Consulting engineer costs – project planning, design, permitting, construction oversight

Dam removal costs can range from tens of thousands (of dollars) to millions, depending on size and condition. Removal costs are primarily the dam owner’s responsibility; however, in some instances, private, local, state, or federal funding may be available. Funding is dependent on site-specific cases and the financial ability of the dam owner. It is important to research potential funding sources that could contribute to the project.

Where to Start

For specific guidance on the dam removal process in your state, talk to: 

  • The State Dam Safety Regulatory Office
  • The State Environmental Protection Office
  • State Historic Preservation Office
  • ASDSO – similar project case studies
  • American Rivers – provides dam removal and restoration guidance and funding options

General Steps for Dam Removal

The following are general steps in a dam removal project. Steps can vary, from project to project, due to site-specific engineering, environmental, and community issues. The expected timeframe of a dam removal project is typically two to three years from conception to completion. In some cases, not all steps will be necessary. Therefore evaluate each step presented here to determine if it is necessary for your project.

1) Site Reconnaissance

  • Determine the approximate age of the dam, history of modifications
  • Review current use, legal rights (dam and impoundment)
  • Research land ownership (around impoundment, dam)
  • List infrastructure impacts (utilities, roads, bridges, etc.)
  • Identify critical biological resources (habitats, wetlands)
  • Identify support/funding opportunities
  • Assess historical land use (gauge sediment quality)
  • Assess community interests/concerns

2) Feasibility Study

  • Collect existing data, survey existing conditions
  • Assess sediment quantity, quality, mobility
  • Assess hydrology and hydraulics
  • Develop conceptual plans (removal/modification of structures, sediment management,
  • channel / riparian habitat restoration)
  • Analyze other site-specific issues (utilities, wetlands, rare/endangered species, historical sites, etc.)
  • Identify required federal, state, and local permits (complete necessary calculations)
  • Develop cost estimates
  • Develop conceptual drawings (dam removal and channel restoration)

3) Work with the Community

  • Hold stakeholder/community meeting(s) -review alternatives, obtain local support for preferred alternative
  • Hold pre-permitting meeting(s) – contact or meet with local, state, and federal planners, environmental regulators, dam safety officials, etc. to clarify/confirm regulatory review requirements

4) Final Engineering Design & Permitting

  • Develop design plans for the preferred alternative (modifications, dam removal, and stream restoration)
  • Develop project specifications (specify construction equipment, material specs and quantities, project sequencing, staging areas, and site access)
  • Provide an Engineer’s Cost Estimate for construction
  • File all regulatory permits
  • Attend public hearings
  • Address public and regulatory agency comments and permitting conditions

5) Project Implementation and Construction

  • Hire contractors
  • Drawdown impoundment
  • Address impoundment sediments, as necessary
  • Modify/remove dam structure
  • Stream channel restoration
  • Impoundment revegetation

Dam Owner Academy: Removing a Dam

The Dam Owner Academy is a series of videos to educate and inform owners on all aspects of operating and maintaining a dam safely. The videos concisely present the critical basics of owner responsibilities and are available as a free resource for owners and those conducting owner outreach programs. This video covers removing a dam.

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Save this page as a printable Dam Owner's Fact Sheet [PDF]