DEEP is excited to be getting back to our new normal consistent with the direction of Governor Lamont and as a result of the rapidly improving COVID-19 situation in Connecticut. Starting no later than June 1, all customer facing services will resume normal business operations. For detailed information for what this means at DEEP and for the public we serve, visit our "New Normal" website: DEEP New Normal Information

Connecticut Stream Flow Standards and Regulations

Final SF Class Map

  Map of Final Adopted Stream Flow Classifications  


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 for these basins 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 20, 2018.  Stream flow classifications for the Housatonic, Hudson and Southwestern were finalized on March 26, 2019.  Classifications for all streams across the state are now complete.

Additional Information:

Summary of Stream Flow Regulations

Stream Flow Classification Process

Frequently Asked Questions

History of Regulation Development

Stream Flow Data Links and Background Documents


Attention: Owners or Operators of Dams

Initial Reporting Due - Stream Flow Reporting Form or Dams

Owners or operators of certain dams located throughout the state 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).  There are several due dates based on the location of the dam (see table below).

Significant Dates for Streamflow Release Requirements
 Basin(s) Classifications Published: Initial Reporting Form Due: Release Plan Due: Releases Begin:
 Southeast Coastal, Pawcatuck, and Thames River Basins October 7, 2014 October 7, 2015 October 7, 2023 October 7, 2024
South Central Coastal Basin September 6, 2016 September 6, 2017 September 6, 2025 September 6, 2026
Connecticut River Basin February 20, 2018 February 20, 2019 February 20, 2027 February 20, 2028
Housatonic, Hudson, and Southwestern Coastal Basins March 26, 2019 March 26, 2020 March 26, 2028  March 26, 2029
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 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
Guidance for De Minimus Demonstration 

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 or

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 on January 15, 2021