Executive Summary

Introduction & Background

Contaminated stormwater runoff is a major source of water pollution in urban areas. When precipitation or storm events occur, it is possible for the resulting stormwater to run along impervious surfaces, collect numerous harmful pollutants, and even discharge these pollutants into large bodies of water.  Contaminated stormwater runoff can have adverse public health effects and cause both environmental and economic detriment.  Because of the possibility of flooding from heavy rainfall, drainage systems are needed to redirect the stormwater runoff.  However, drainage systems can be a gateway for pollutants to enter water bodies.  Municipal Separate Storm Sewer Systems (MS4s) are meant to help control and manage the flow of stormwater runoff.  

The 2016 Massachusetts Small MS4 General Permit specifies the requirements for operating a small MS4 in Massachusetts.  The Massachusetts regulation for small MS4s falls under Phase II of the federal mandate – the NPDES stormwater program.  The permit requires compliance with six minimum control measures.  Under the third minimum control measure – Illicit Discharge Detection and Elimination – operators of small MS4s are required to map their MS4 so infrastructure can be identified and located.  By producing a map of an MS4, municipalities and MS4 operators can better address how and where to treat stormwater, further reducing its possible adverse effects on public health, the environment, and the economy.

The Central Massachusetts Stormwater Coalition (CMRSWC) is a group of municipalities that work together to more effectively manage stormwater in Central Massachusetts.  The CMRSWC also works toward public education and outreach on stormwater in efforts to gain more support in stormwater management efforts.

MS4 infrastructure is interconnected across town borders, state roads, and properties in the CMRSWC municipalities.  Municipalities must collaborate with state agencies who own, manage, and map the interconnected infrastructure to create a fully comprehensive map of their MS4.  Of the state agencies that the CMRSWC municipalities may work with, the Massachusetts Department of Transportation (MassDOT) is of most interest because of the number of state roads that run through Central Massachusetts.  


The goal of our project was to facilitate the collaboration and integration of geospatial data between CMRSWC municipalities and the MassDOT.  We created a document for the CMRSWC municipalities that provides recommendations for improving their relationship and data integration with the MassDOT in meeting the requirements of the 2016 Massachusetts Small MS4 General Permit.  We worked at the goal for our project through four main objectives.  

  1. Identify the degree of information included in the municipalities’ and MassDOT’s geospatial data and how it is managed    
  2. Identify how geospatial data is shared between organizations
  3. Identify what data gaps or constraints exist in the integration of stormwater sewer system geospatial data
  4. Develop an approach to address data gaps and to facilitate interorganizational collaboration 

In a case study methodology approach, we focused on three municipalities within the CMRSWC (Auburn, Framingham, and Holden).

First, we obtained maps from the three CMRSWC municipalities and the MassDOT to identify and establish the base level of geospatial data included in the MS4 maps.  Next, we interviewed key staff members involved in MS4 mapping from the three municipalities, the MassDOT, and the Department of Conservation and Recreation (DCR) to determine the specifics of their mapping methodologies and how MS4 geospatial data is shared between organizations.  We then analyzed both the geospatial data provided and the qualitative data obtained in our interviews to, ultimately, identify and address data gaps or interorganizational constraints in the integration of MS4 geospatial data.  In carrying out our four objectives, we were able to compile our findings and make recommendations included in the guidance document.  

Findings & Results

Through the thematic analysis of both the MS4 geospatial data acquired and the qualitative data obtained by interviews, we determined several hindrances in the stormwater management operations of municipalities and the MassDOT that impede the ability to optimally integrate data.  To start, a major finding was limited funding.  MS4 regulation is a federally unfunded mandate, meaning that municipalities must scramble within their budget or taxation to enact basic stormwater management efforts.  Limited funding is the direct cause of another major finding: limited staffing.  There is an ongoing issue of limited staffing for the stormwater management departments in the three municipalities we interviewed and the MassDOT.  Most of the responsibilities that come with MS4 mapping are often placed on an existing staff member because designated stormwater staff is not hired.

Another finding was the relationship between the three municipalities and the MassDOT. The municipalities we interviewed have essentially had little to no contact with the MassDOT in past years in terms of MS4 mapping efforts, obstructing the process of integrating maps.  The municipalities were also unaware of GeoDOT – the MassDOT’s public GIS geodatabase. GeoDOT contains useful resources for municipalities including the MassDOT’s drainage data.  With Hung Pham (Stormwater Program Coordinator) as the primary contact for the MassDOT’s MS4 mapping efforts, GeoDOT will need to be utilized by municipalities to minimize any unnecessary contact with the MassDOT.

When analyzing mapping methodologies and MS4 geospatial data, we found that the three municipalities’ maps are more detailed in comparison to the MassDOT’s.  The MassDOT’s data is condensed and standardized.  With its choice in both symbology and color scheme, the MassDOT’s map provides a viewer with a quick understanding because of its clear discernment of infrastructure.  


We developed three categories of recommendations for a benefitting a future collaborative relationship between CMRSWC municipalities and the MassDOT.  The first recommendation is improving readability and integration of MS4 maps.  To make the process of improving readability and integration of MS4 maps easier, we recommend that the CMRSWC municipalities follow the MassDOT’s standards for map symbology, condense infrastructure classes, adopt a color scheme to identify ownership, and consider two tiers of attributes.  The second recommendation we developed targets improving the communicative relationship between CMRSWC municipalities and the MassDOT.  Municipalities must first know who to contact in the organization and how to use GeoDOT to minimize unnecessary communication that may overwhelm a point contact.  Lastly, future considerations for limited staffing and funding were developed as the third recommendation.  Our third recommendation discusses the possibility for volunteer or intern programs and initiatives with universities, community colleges, K-12 schools, companies, organizations, or watershed associations to lessen the workload that comes with MS4 compliance placed on municipalities.  While this recommendation may be an option for municipalities, educating volunteers or interns about stormwater infrastructure and how to use GIS can be time consuming.  To assist in developing an educational program for a volunteer or intern program is why additional educational resources are provided with this recommendation.