DEEP: Connecticut Stream Flow Standards

Connecticut Stream Flow Standards and Regulations

{Chapman Falls, East Haddam}
Chapman Falls, East Haddam
{Blackledge River, Marlborough}
Blackledge River, Marlborough


In 2005 the Connecticut General Assembly passed Public Act 05-142 (CGS Section 26-141a and b) which required the Department of Energy and Environmental Protection (DEEP) to work with the Department of Public Health and stakeholders to update standards for maintaining minimum flows in rivers and streams. The act required these standards to balance river and stream ecology, wildlife and recreation while providing for public health, flood control, industry, public utilities, water supply, public safety, agriculture and other lawful uses of water.

Extensive effort by DEEP and numerous stakeholder work groups culminated in adoption of the Stream Flow Standards and Regulations on December 12, 2011. The process of classifying the streams and rivers of the State began with the Southeast Coastal, Pawcatuck and Thames Major basins and the stream flow classifications were finalized on October 7, 2014. Stream flow classifications for the South Central Coastal River Basin were finalized on September 6, 2016.  Stream flow classifications for the Connecticut River Basin were finalized on February 6, 2018.  The remaining basins (Housatonic, Hudson and Southwestern Coastal Complex) are anticipated to be completed by the beginning of 2019.


Attention: Owners or Operators of Dams

Initial Reporting for Dams on Classified Streams in the Connecticut River Basin

Owners or operators of certain dams located in the Connecticut River Basin MAY BE required to  submit an initial reporting form to the Department of Energy and Environmental Protection (DEEP) under the Stream Flow Standards and Regulations (26-141b-7(a) of the Regulations of Connecticut State Agencies) by February 6, 2019. This includes dams on river and stream segments in the following towns: Andover, Avon, Barkhamsted, Berlin, Bloomfield, Bolton, Bristol, Burlington, Canton, Chester, Colchester, Colebrook, Columbia, Cromwell, Deep River, Durham, East Granby, East Haddam, East Hampton, East Hartford, East Lyme, East Windsor, Ellington, Enfield, Essex, Farmington, Glastonbury, Granby, Guilford, Haddam, Hartford, Hartland, Harwinton, Hebron, Killingworth, Lebanon, Lyme, Madison, Manchester, Marlborough, Meriden, Middlefield, Middletown, New Britain, New Hartford, Newington, Norfolk, North Branford, Old Lyme, Old Saybrook, Plainville, Plymouth, Portland, Rocky Hill, Salem, Simsbury, Somers, South Windsor, Southington, Stafford, Suffield, Tolland, Torrington, Vernon, Wallingford, West Hartford, Westbrook, Wethersfield, Winchester, Windsor, Windsor Locks, and Wolcott.

Only owners or operators of certain dams are required to submit the Stream Flow Reporting Form for Dams, as follows:

  • owners or operators of dams that will be required to make releases from the dam in accordance with the regulations (these are primarily large impoundments with consumptive withdrawals, like drinking water supply reservoirs); and 
  • certain owners or operators for which submission of the form is a provision of exemption from making releases (primarily water utilities, golf courses and recreational lake dam owners).

DEEP strongly encourages all owners or operators of dams in the subject basins to review the Stream Flow Reporting Form for Dams. The form takes owners or operators of dams through the exemptions and what (if anything) is required for each. You may wish to begin by reviewing Part III, starting on page 3 of the Stream Flow Reporting Form for Dams, to determine if you meet any of the exemptions and if submission of the form is required before filling out the Stream Flow Reporting Form for Dams in its entirety.

Stream Flow Reporting Form for Dams (Word / PDF)  

Past Due Dates:

  • Southeast Coastal, Pawcatuck, or Thames River Basins - October 7, 2015
  • South Central Coastal Basin - September 6, 2017
Please review the Stream Flow Reporting Form for Dams to determine whether your site is subject to reporting requirements if you have not done so already.

Questions can be directed to DEEP at (860) 424-3020.

      Map of Final Adopted Stream Flow Classifications  to date. 


Additional information may be found at:

Stream Flow Regulations

Stream Flow Classification Process

Frequently Asked Questions

History of Regulation Development

Stream Flow Data Links and Background Documents

Contact Information:

If you have questions or for further information on the program, please contact us at:

Connecticut Department of Energy and Environmental Protection
Bureau of Water Protection and Land Reuse 
Water Planning & Management Division
79 Elm Street
Hartford, CT 06106-5127

Phone: (860) 424-3020
Fax: (860) 424-4055

Content Last Updated onFebruary 7, 2019