Municipal Stormwater Management Collaboration in the Mystic River Watershed

Over the course of two years, EPA Region 1 utilized Urban Waters Program contractor support to directly assist communities in the Mystic River watershed in developing strategic approaches for advanced local stormwater management to improve water quality and build resilience into stormwater systems. Partners for this work included municipal representatives, MassDEP, the Mystic River Watershed Association (MyRWA), and EPA technical and facilitation contractors.

As identified in the Mystic River Watershed Eutrophication Analysis, extensive impervious cover and development in the watershed have led to water quality impairments, flooding, and excessive low flow conditions during droughts. The freshwater portion of the watershed faces multiple water quality impacts related to cultural eutrophication, including excessive algal growth, harmful cyanobacteria blooms, and excessive native and invasive macrophyte growth.

In the summer of 2018 EPA solicited letters of interest from communities within the Mystic River Watershed that were willing to engage with a project team to better understand how to overcome obstacles for better stormwater management that focuses on nutrient reduction. From December 2018 to June 2019, EPA and partners assisted the Town of Arlington and the Town of Winchester in a series of five half-day meetings. Following the success of this project, EPA and partners collaborated with four additional communities (the City of Cambridge, the Town of Lexington, the Town of Reading, and the Town of Watertown) in three half-day meetings with additional technical webinars between December 2019, and September 2020.

For these sessions the project team sought to:

• Understand the challenges and constraints municipalities face in implementing nutrient reduction strategies, including stormwater management retrofit programs, and identify technical and informational needs for overcoming them;
• Identify the ways that communities can make progress towards nutrient reduction goals while also addressing related issues, for net gains in water resource restoration and protection (for example, incorporating the best controls as part of urban renewal, redevelopment, municipal operations and stormwater system maintenance);
• Share critical stormwater management information related to developing effective and affordable retrofit programs (such as: performance curves, case studies quantifying the benefits of small design capacity controls, and streamlined approaches for long-term stormwater management that will help with prioritizing future water resource management projects);
• Quantify the multiple benefits of long-term stormwater retrofit programs;
• Identify regulatory challenges faced by the communities; and
• Identify affordable stormwater management and nutrient reduction strategies.

The facilitation of open dialogue between municipal officials and state and federal agency participants was an essential part of the project. Dialogue among the participating municipalities was just as important and led to joint brainstorming and problem solving for one another. Through these conversations, the municipalities were able to identify universal barriers to effective stormwater management that the agencies can help work on. The program also demonstrated the importance of consistent participation, which allowed complex conversations about difficult challenges to build and continue over the course of the projects. Municipalities participating in this program dedicated ample time to the process – including not only the scheduled half-day meetings, but also between meeting conference calls and work with the contractors that added significant value.

EPA contractors, through multiple working meetings, assisted participating municipalities in reviewing their existing regulatory mechanisms around changing land use and the creation of impervious cover in their communities (development and redevelopment of sites) and suggested improvements to address water quality. Contractors also helped to develop low-cost simple stormwater control designs that can be easily replicated and flexibly sized to fit within constrained rights of way or other municipal properties. During the later phase of this work, contractors also assisted municipalities in thinking about how to manage and track dispersed stormwater controls throughout their communities.

The dialog among municipalities and regulators about stormwater management will inform future work throughout the watershed as all communities begin to tackle the nutrient issues identified by the Mystic River Watershed Eutrophication Analysis completed by MassDEP and EPA. The project demonstrated the value of collaboration for constructive problem solving not only among municipalities, but also among the regulators, contractors and watershed groups. EPA believes the project is an important starting point for the significant stormwater management work that is needed in the Mystic River Watershed. The deliverables from these collaborative meetings, which will be made available online shortly, as well as the experience of the participating communities, may help other communities in the watershed to consider a more comprehensive and innovative approach to stormwater management considering the significant pollution reductions that the watershed needs.