Stormwater Improvement Project to Consider

To All,

Stormwater pollution is a serious problem in many of your watersheds, and many of you are using green stormwater infrastructure projects to address it.  I wanted to share information about a project one of your fellow members, the Charles River Watershed Association, has implemented in Chelsea, Massachusetts so that you can learn from their experiences too.


Blue Cities: Stormwater Improvement Project for Mace Apartments, Chelsea

Project Overview

The Charles River Watershed Association (CRWA) installed bio-filters within the Mill Hill neighborhood in Chelsea, which sits on a small neck of land bounded by Chelsea Creek and Mill Creek. Like other Chelsea neighborhoods, the site consists mostly of residential buildings interspersed with industrial and commercial development. Given the high amounts of impervious pavement in the area, stormwater runoff is a major contributor to pollution levels in both creeks. After analyzing the impact of this site on the water quality in Mill Creek, CRWA selected this site as a pilot project for implementing green infrastructure retrofits and monitoring the results on both water quality improvement and run off reduction from the site.

Benefits to installing bio-filters
Installed three bio-filters in a parking lot at the Mace Apartment Complex at the intersection of Crescent Avenue and Clinton Street

  • Improved quality of water by filtering stormwater runoff prior to it discharging into Mill Creek
  • Provided comprehensive training on maintenance to Chelsea Department for Public Work and Chelsea Housing Authority maintenance staff
  • Provided opportunity for residents to be involved in project design and implementation

Challenges faced during construction and post construction monitoring

  • Bid process and construction contract award was challenging and very time consuming
  • The lowest bid contractors were inexperienced and required extra supervision
  • Post construction monitoring involved the use of automated sampling equipment that required a steep learning curve
  • Ongoing maintenance has been a challenge

Blue Cities

CRWA’s Blue Cities Initiative works to reengineer urban landscapes to incorporate the design of natural green corridors and infrastructure. By restoring urban greenscapes Blue Cities Initiative also reestablishes natural hydrology that replenishes groundwater, reduces the pollution of stormwater to the Charles River and reduces flood risk. For more information on Blue Cities visit

Bio filter in center vegetated island
Bio filter along Mill Creek and Clinton Street