City of New London

The City of New London has been issued a "General Permit for the Discharge of Stormwater from Small Municipal Separate Storm Sewer Systems" by Connecticut Department of Energy & Environmental Protection (CTDEEP). The permit is issued to ensure the City of New London is compliant with the requirements of EPA’s Clean Water Act (CWA) for municipalities and the developed areas within them.

The City of New London has created a Stormwater Management Plan, and prepares an annual report to be submitted to CT DEEP to demonstrate compliance with the permit and stormwater management plan. There are six minimum control measures for the plan:

  1. Public Education and Outreach on Stormwater Impacts
  2. Public Involvement and Participation
  3. Illicit Discharge Detection and Elimination
  4. Construction Site Stormwater Runoff Control
  5. Post-construction Stormwater Management in New Development and Redevelopment
  6. Pollution Prevention and Good Housekeeping for Municipal Operations

The annual report, submitted July 16, 2014, highlights each of these measures and explains what the City has been doing for each minimum measure. At this time the city of New London does not have an ordinance for the discharge of stormwater, but zoning regulations and the stormwater plan are the mechanisms that drive compliance with the permit. Developed areas that disturb more than or equal to 1 acre are required to have stormwater controls in place, and the property owner is responsible for an adequate long-term operations and maintenance plan for the BMPs installed onsite.




C. Design, Layout and Location

Drainage - In addition to the requirements of other sections of these regulations, the use of on-site natural filtration functions is encouraged as part of currently accepted Best Management Practices in the reduction of sediment and pollutants. Additionally; drainage shall not be directly channeled to wetlands or watercourses through new piping, flow though natural existing drainage systems shall be maintained as much as possible, and shall not result in a net increase of runoff from the site for the 25-year storm. Also, for previously undeveloped sites, the stormwater management system shall include the retention and filtration of the first inch of runoff from impervious surfaces (excluding roofs).

20) Stormwater Drainage

a) Parking areas shall be graded and drained to dispose of all surface water in accordance with sound engineering principles.

b) No storm water drainage shall be allowed to cross any sidewalk area or public streets.

c) Drainage shall be designed by a professional engineer licensed in the State of Connecticut.

d) The commission shall require that a stormwater management plan is submitted for all proposed parking lots consisting of twenty-five (25) or more parking spaces. However, the Commission may require a stormwater management plan for any proposal if it determines that the site disturbance and proposed use may cause significant nonpoint source pollution. The stormwater management plan shall provide, but not be limited to at a minimum the following information: (The City’s Office of Development and Planning (ODP) has been charged with the responsibility to prepare a recommended format for stormwater management plan submissions to the Commission under these regulations. All applicants are encouraged to consult with ODP staff prior to application submission.)

  1. Soil characteristics including soil types, hydrologic soil group, and depth to bedrock and groundwater where necessary.
  2. DEP ground/surface water quality classification of the site.
  3. Location and description of all proposed best management practices (BMPs) both for construction activities and post-construction long-term nonpoint source pollution control.
  4. Proposed maintenance and operation manual or schedule for any stormwater control methods.
  5. Hydrologic analysis and calculations of stormwater runoff rates and water quality pollutant concentrations including suspended solids removal rates for pre and post development.
  6. To the extent practicable, maintain post-development peak runoff rate and average volume at levels that are similar to pre-development levels and reduces post-development average annual total suspended solid (TSS) loads by 80%.

e) Stormwater management systems shall be designed and maintained to manage site runoff in order to prevent flooding, control peak discharges where required, and maximize retention and water quality treatment on-site.

f) On proposed sites with discharges of stormwater within five-hundred (500) feet of coastal waters, the stormwater management system shall be designed to retain and treat the volume generated by the first one (1) inch of rainfall unless a demonstration can be made that specific site constraints prevent meeting this goal. In such case, the stormwater management system should be designed to retain and treat the maximum amount that is technically feasible.


Inland Wetlands & Watercourses Regulations of the City of New London – Amended January 23, 2012

Any development activity occurring in this area is subject to more stringent standards. The map of regulated areas, [link here] , delineates the general location and boundaries of inland wetlands and the general location of watercourses. The link to these regulations is at the bottom of the page.



NEW london General Permit for the Discharge of Stormwater from Small Municipal Separate Storm Sewer Systems

July 16, 2014

Minimum Control Measure Number 5: Post-construction Runoff Control

Specific permit requirements for this measure include:

i.Develop, implement, and enforce a program to address stormwater runoff from new development and redevelopment projects that disturb greater than or equal to 1 acre. This program should ensure that controls are implemented to require appropriate infiltration practices, reduce impervious surfaces, and reduce sediment discharge. This program should be enforceable by an ordinance or other mechanism.

ii.Develop an ordinance or other mechanism to support the program developed under Item i.

iii.Develop and implement strategies that include a combination of structural and nonstructural BMPs that are appropriate for the City.

iv.Ensure adequate long-term maintenance and operation of stormwater BMPs that are installed.

The following BMPs are being implemented for this control measure:


5.1 Item i. Review land use regulations to meet requirements of MS4 Permit and E&S guidelines. The City contracted with Milone & MacBroom, Inc. to assist in the review of the current land use regulations. The regulations have been reviewed, and the City Council is in the process of establishing and approving a Stormwater Authority.

5.2 Item ii. Develop post-construction ordinance or regulation. Requirements for post-construction stormwater quality management are currently addressed via conditions of approval, which note requirements for the maintenance of stormwater water quality structures in accordance with  the manufacturers' recommendations. In an effort to incorporate language into the Zoning and Subdivision Regulations of the City, the City contracted with Milone & MacBroom, Inc. to assist in the preparation of appropriate language to address this element. The modified language will require all development within the City limits to conform to the regulations set forth in the MS4 Permit, the 2004 Connecticut Stormwater Quality Manual, the 2000 Connecticut Department of Transportation Drainage Manual as well as the 2002 Connecticut Guidelines for Soil Erosion and Sediment Control. A draft of that ordinance was submitted to the City and remains under review

5.3 Item iii. Develop and implement post-construction BMP strategy. The City currently addresses requirements for post-construction requirements in all site plan reviews via conditions of approval. The Planning and Zoning Commission intends to evaluate that previously mentioned modification to the land use regulations to incorporate appropriate post-construction stormwater BMPs. In addition, during pre-application meetings with potential applicants, City staff will continue to discuss the need for proper stormwater management and require that plans submitted be consistent with the Connecticut Stormwater Quality Manual.

5.4 Item iv. Develop program to ensure long-term operation and maintenance of BMPs. Contrary to many of Connecticut's more rural towns, the compact size and highly urbanized nature of New London has precluded the construction of many detention and retention basins that the City must now maintain. Therefore, BMP maintenance of basins (assuming any exist) is the responsibility of the individual property owner(s). For new land use applications, a Stormwater Maintenance Plan is requested from the applicant to spell out the requirements of each element of a proposed system. It should also be noted that the City was a participant in a  Stormwater Management Pilot Program that reviewed the feasibility of establishing a separate Stormwater Authority, which would use a fee-based system to fund all stormwater maintenance, improvements, and compliance activities. Upon finalization of the Stormwater Authority amendments, the City Council will discuss the next steps and submit a report to the legislature with its findings. The City is in the process of evaluating the conclusions of the study, which included recommended changes to the enabling legislation for Stormwater Authorities (not adopted in 2012). However, it is considering establishment of a Stormwater Authority to possibly be implemented in a following year. Land use and engineering staff will evaluate incorporating the implementation of that plan into the condition of approval for each site. 

The current land use regulations require a Maintenance and Operations Manual for any stormwater control method used on sites with 25 or more parking spaces and require that, to the extent practicable, the owner is to maintain a postdevelopment peak runoff rate and average volume of stormwater similar to the preconstruction rate. The owner is also to reduce the postdevelopment average annual Total Suspended Solid (TSS) loads by 80 percent. There are regulations currently in place regarding any parking lot within the City to have a stormwater management system that is designed and maintained to manage site runoff to prevent flooding, control peak discharges where required, and to maximize the retention and water quality on site. In addition to that, if any site discharges stormwater within 500 feet of coastal waters, the stormwater management system shall be designed to retain and treat the volume of water generated by the first 1 inch of rainfall on the site unless there is a demonstrated site constraint that would make that impossible.

Approvals issued by the Planning and Zoning Commission require, where determined to be necessary, annual reporting to the City regarding compliance with the Zoning Regulations and the conditions of the Site Plan approval regarding long-term operation and maintenance of the stormwater drainage system and BMPs.


New London Stormwater Documents