Connecticut Stormwater Update

Breaking Down Connecticut’s Current 2024 Stormwater Quality Manual

The Connecticut Department of Energy & Environmental Protection (CT DEEP) enacted the Connecticut Stormwater Quality Manual (CT SWQM) in March 2024. The guidelines in this manual apply to post-construction stormwater controls for new developments, redevelopments, and upgrades to existing developments, such as retrofits.

Permitting entitlement efforts submitted after this date will be encouraged to abide by the latest guidelines. The guidelines can significantly impact project costs if not strategically implemented.

Here’s what development teams should know to remain compliant and to strategize stormwater management design moving forward.

What’s Happening?

The CT DEEP recently approved the issuance of the 2024 CT SWQM, which supersedes the previous 2004 CT SWQM and the LID Appendix of 2011. Effective March 30, 2024, these new regulations apply to all projects.

Many state agencies and municipalities have already incorporated the manual by reference into municipal planning, subdivision, inland wetlands regulations, and permit programs including the CT DEEP stormwater general permit. The CT DEEP MS4 General Permit, for example, specifically requires municipalities to update their local regulations to incorporate post-construction stormwater management requirements that meet or exceed the guidance contained in the Connecticut Stormwater Quality Manual.

Why Now?

Stormwater management, or the scientific understanding of the water quality impacts of stormwater runoff, has significantly evolved since the publishing of the 2004 Connecticut Stormwater Quality Manual and the 2011 LID Appendix.

Rising precipitation trends and technological advancements in structural stormwater systems, combined with federal and state agencies’ increased focus upon managing stormwater during both the construction and post-construction phases have all contributed to the updating of stormwater guidelines.

What It Means for Developers

Better Clarification on Redevelopment Sites and Stormwater Retrofitting

The new guidelines bring much-needed clarity regarding redevelopment sites and the retrofitting of stormwater systems. This improved guidance can potentially lead to significant cost savings. With clearer rules, design teams can more effectively plan and execute stormwater management strategies, ensuring compliance while optimizing their budgets.

Increased Stormwater Controls for Previously Undeveloped Sites

The new regulations do introduce additional challenges for previously undeveloped, or greenfield sites. Developers may face increased site costs due to a 30% increase in the amount of rainfall required to be treated (1.3 inches vs the previous 1.0 inch). This means that stormwater management systems need to be more robust to handle the increased volume.

Additionally, the identification of principal pollutants in stormwater and the recommended strategies for their removal necessitate more comprehensive and potentially costly measures. The emphasis on Low Impact Development (LID) site planning and design techniques further requires developers to integrate small-scale green infrastructure early in the design process, adding another layer of complexity and expense to project planning.

Assistance with Previously Approved Developments

Bohler offers professional assistance to developers navigating these changes, especially those who have purchased developments approved before March 30, 2024. Our team can help you determine whether existing approvals allow for the construction of previously approved stormwater controls or if additional measures will be required under the new regulations.

This assessment is important as requirements can vary significantly depending on specific local municipality and state permitting mandates. By conducting thorough reviews, Bohler assists developers in becoming fully informed and being compliant, avoiding costly delays and modifications.

Integrated Civil and Planning Landscape Architecture Design Teams

Bohler’s strength lies in our integrated approach, combining our site civil and planning, landscape architecture and design teams to incorporate new stormwater and LID features seamlessly into projects.

By addressing these elements early in the design process, we help minimize their impact and cost during construction and beyond. Our multidisciplinary team will assist you in creating stormwater management solutions that are both effective and economically feasible, providing developers with peace of mind and supporting sustainable, regulatory-compliant development practices.

Moving Forward Across Connecticut

While the increased stormwater controls are new to Connecticut in 2024, other states within Bohler’s footprint, including New Jersey, Pennsylvania, and Maryland have already implemented similar regulations. Professionals on our Connecticut team who have worked in these regions are experienced with these design solutions, such that Bohler will work with you to help you save time and money during initial design phase and throughout the development’s lifespan.

Questions about stormwater management design in Connecticut? Connect with our team.