Water Quantity

The Water Quantity Program is responsible for balancing in-stream and out-of-stream water uses for the benefit of Connecticut citizens and the environment. Our goal is to promote water conservation to ensure plentiful water for all users.

Within the Water Quantity Program, the Consumptive Water Diversion Program regulates the withdrawal or transfer of surface water or groundwater exceeding 50,000 gallons per day through permits and registrations. Out-of-stream uses involve removing water or diverting water from surface water or groundwater for an economic use. Some examples of businesses that use the state's water include, but are not limited to:

  • Public water supply companies
  • Golf courses
  • Wholesale plant nurseries
  • Produce growers
  • Ski mountain resorts
  • Various other industries

 Active consumptive water diversion permits and registrations must report daily water use in an annual report to the Department of Energy and Environmental Protection (DEEP). Water use data is collected and analyzed by DEEP in an effort to keep the water budget balanced. The data helps DEEP to make better scientific and policy decisions on consumptive water diversion permits and watershed planning for the future. For more information on water diversion reporting and the requirements, visit the Water Diversion Reporting webpage. 

If you believe you may need a consumptive water diversion permit, please contact the Consumptive Water Diversion program at DEEP.WaterDiversion@ct.gov   

Irrigation of a turf field with a water cannon

Photo: CT DEEP - Example of a permittee diverting water to irrigate grass at a facility

Other Programs and Resources

Aquifer Protection Program

Connecticut Drought Information Center

Connecticut Water Planning Council

Flood Management


Stream Flow Standards and Regulations


United States Geological Survey (USGS) Programs and Links

USGS National Water Dashboard

New England Water Science Center

Current Streamflow Conditions in Connecticut by Station Name and Number

Connecticut Streamflow and Sustainable Water Use Estimator

Content last updated October 24, 2023