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Water Diversion Individual Permits
An Environmental Permitting Fact Sheet

For information on Water Diversion General Permits, visit the List of General Permits Fact Sheet.

Program Overview

This program, administered by the Bureau of Water Protection and Land Reuse, regulates activities which cause, allow or result in the withdrawal from, or the alteration, modification or diminution of, the instantaneous flow of the waters of the state.The Department recognizes two types of diversions; consumptive, and non-consumptive. Consumptive diversions, administered by the Water Planning and Management Division, withdraw ground or surface water for uses such as public water supply, irrigation, power generation, and industrial processing. Non-consumptive diversions, administered by the Land and Water Resources Division (LWRD), involve the physical alteration or modification of a surface water(s). In general, a diversion permit is required for 1) withdrawals of surface or ground water exceeding 50,000 gallons in any 24-hour period, or 2) to conduct activities which result in the modification or alteration of a surface water(s).

Diversions existing on or before July 1, 1982 which were registered with the Department on or before July 1, 1983 do not require a permit. There are exemptions for minor diversions described in the regulations. When making a decision on a water diversion permit application, the Department must consider those factors listed in the authorizing statutes and regulations including, but not limited to, the environmental effects of the diversion and whether the proposed diversion: 1) is necessary, 2) is consistent with long-range water resource management, 3) is consistent with the state plan of conservation and development adopted pursuant to part I of Chapter 297 of the Connecticut General Statues, and 4) will not impair proper management and use of the water resources of the State.

Authorizing Statutes

Sections 22a-365 through 22a-379 of the Connecticut General Statutes (CGS)


Who Must Apply

In general, any person proposing a diversion which was not registered with the Department and, which is not exempt, must apply for a permit.

Consumptive Diversions

You must apply for a permit if you propose to:

  • withdraw groundwater from one or more wells joined in one system whose combined maximum withdrawal exceeds fifty thousand (50,000) gallons of water during any twenty-four hour period;
  • withdraw surface water (including skimming of flood flows) in excess of fifty thousand (50,000) gallons during any twenty four hour period;
  • transfer water from one public water supply distribution system or service area to another where the combined maximum withdrawal from any source supplying interconnection exceeds fifty thousand (50,000) gallons during any twenty-four hour period;
  • expand use of a registered public water supply source beyond a service area as identified (1) within registration documents, (2) in a water supply plan submitted prior to October 1, 2016, or (3) beyond an exclusive service area identified on the Department of Public Health’s 2016 Public Water Supply Management Area maps; or
  • modify a registered diversion.
Non-Consumptive Diversions

You must apply for a permit if you propose to:

  • collect surface water runoff, i.e., storm water drainage, from a drainage area greater than 100 acres;
  • construct or otherwise modify roadway crossings or culverts which provide detention or retention of watercourse flows either by design or default, or to otherwise modify or alter hydraulic characteristics or capacity;
  • relocate, retain, detain, bypass, channelize, pipe, culvert, ditch, drain, redirect, fill, excavate, dredge, dam, impound, dike, or enlarge or diminish waters of the state.

Permit Need Determination

If there is uncertainty in whether or not a permit is needed, a formal letter can be sent to the address at the bottom of this Fact Sheet for a Permit Need Determination. The letter should include specifics on the diversion activity being pursued, and any applicable questions. In response, the Department will send a formal correspondence on whether or not a permit is needed.

Required Application Documents

The LWRD License Application Form (DEEP-LWRD-APP-001L) for Inland Water Resources Activities, and various technical documents in support of the application. Supporting documents include, but are not limited to, engineering and environmental reports, plans and specifications describing the proposed activity and its impact on the environment, long-range water conservation and drought emergency contingency plans, and documentation of what alternatives were considered for the project. A checklist of application documents is included on form DEEP-LWRD-APP-001L, including the LWRD License Application Transmittal Form (DEEP-LWRD-APP-001) and Applicant Compliance Information (DEEP-APP-002)


Fees are based on either the volume of water withdrawn, in the case of consumptive use diversions, or the size of the watershed involved, in the case of a hydraulic modification of surface flow. For municipalities, a 50% discount applies:

For consumptive use

Greater than 50,000 gallons per day (gpd) but less than 500,000 gpd


500,000 gpd or more but less than 2,000,000 gpd $4,000.00
2,000,000 gpd or more $6,250.00
All others

Tributary watershed area above the diversion is 0.5 square miles or less

Watershed area larger than 0.5 square miles but smaller than 2.0 square miles $4,000.00
Watershed area is 2.0 square miles or larger $6,250.00

Review and Processing

Upon receipt of the application, application fee and a certified copy of the Notice of Application, the application is assigned to a project coordinator and is reviewed for sufficiency. If the application is sufficient, a detailed technical review is initiated. This review consists of an evaluation of the technical documentation provided in the application as well as an assessment of the site and of the anticipated effects of the proposed activity. The application will also be reviewed by the Department's Fisheries and Wildlife Divisions and the Natural Diversity Data Base Staff and will be forwarded to the CT Departments of Public Utility Control and Public Health, Water Supplies Section. If Department staff have questions or require additional information about the proposed project, the project coordinator will contact the applicant or his designated agent. Upon completion of this technical review, a tentative determination to grant or deny the permit application will be made by the Commissioner. A Notice of Tentative Determination will be published in a newspaper having a general circulation in the affected area and public comments will be solicited on the tentative determination. In some cases, a public hearing may be held. After completion of the technical review and consideration of any public comments, and subsequent to the close of any hearing, DEEP will issue a final decision on the permit application.

Unique Processing Features

The applicant must, in accordance with CGS Section 22a-370, notify the chief executive officer of the town or towns in which the proposed diversion will take place within ten days after filing the application with DEEP.

Public Participation

The applicant is responsible for publishing a Notice of Application when the application is submitted to DEEP. Once this notice is published, the applicant must send a copy of the notice to the Chief Elected Official of the municipality in which the regulated activity is proposed, and send a copy of the notice, along with the Certification of Notice Form – Notice of Application (DEEP-APP-005A), to DEEP. After the technical review, DEEP will publish a Notice of Tentative Determination to grant or deny the permit. If permit issuance is proposed, a draft permit with proposed terms, limitations, and conditions is prepared and made available for review and comment, and notice of the formal hearing on the application is published. If DEEP determines that the proposed diversion is necessary, will not significantly affect long range water resource management or the environment, and will not impair proper management and use of the water resources of the state, DEEP may publish notice of its intent to waive the hearing requirement. However, if DEEP receives a petition signed by at least twenty-five persons requesting a hearing no later than thirty days after publication of notice of DEEP's intent to waive the hearing, DEEP shall hold a hearing on the application. DEEP may require an applicant to post a sign on the site or to provide any other reasonable form of notice necessary to apprise the public and abutting landowners of the proposed activity.

Average Processing Time

For this permit program, processing time for a typical application, based upon recent experience is less than 180 days. Past performance is not a guarantee of future processing timeframes. In order to increase the efficiency of application processing, it is highly recommended that you, as the applicant, carefully read all application instructions prior to completing and filing an application. A pre-application meeting with DEEP staff may be necessary.

Permit Duration

Permits generally require that an authorized diversion be constructed and initiated within three years after issuance of the permit. The expiration date of the permit, which generally does not exceed five years, is established by DEEP based on its consideration of existing uses and allocations of the water resources within the watershed and pertinent facts and circumstances particular to the proposed project. The maximum duration of a water diversion permit by law is twenty-five years. An application to renew a diversion permit must be submitted at least 120 days prior to the expiration date of the permit.

General Permits:

A general permit for certain minor activities may be obtained if the commissioner determines that such activity would cause minimal cumulative environmental effects, and will have no adverse effect on existing or potential uses of water for potable water supplies, hydropower, flood management, water based recreation, industry or waste assimilation. For more information on General Permits, see the List of General Permits Fact Sheet.

Contact Information
Consumptive Diversions:

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

Non-Consumptive Diversions:

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

This overview is designed to answer general questions and provide basic information. Refer to the appropriate statutes and regulations for the specific regulatory language of the different permit programs. This document should not be relied upon to determine whether or not an environmental permit is required. It is your responsibility to obtain and comply with all required permits.

Fact Sheet: DEEP-IWRD-FS-106

Users Guide to Environmental Permits

Content Last Updated March 10, 2020