Blog - Charles River Watershed Association

Visioning a better Mass Pike Allston Interchange

Posted by Margaret VanDeusen

3/12/18 3:12 PM

As you may have heard, the Massachusetts Department of Transportation (massDOT) plans to rebuild the Mass Pike Allston Interchange over the next decade to replace aging infrastructure. Meanwhile, Harvard University is developing plans for its Enterprise Research Campus nearby. The concurrence of these projects while Boston is striving to achieve climate resiliency provides an exceptional opportunity to create a green neighborhood which promotes access to the river while providing resiliency to climate change. It's an opportunity we can't afford to miss.

Beacon Park Yard

Aerial view of Beacon Park Yard and I-90 in Allston |  Source:  Nick Allen, CC BY-SA 4.0

As a member of the I-90 Allston Interchange Task Force, CRWA has advocated since 2014 for increased flood control, reduced pollution and improved public access to the Charles River to be central to a proposal for the new I-90 interchange.


CRWA's principles for a resilient I-90 Allston Interchange 

  1. Planning and design for climate change resilience
  2. Creation of new parkland and better bicycle and pedestrian access to the Charles River
  3. Creation of a blue-greenway corridor (network of connected parks) and green streets
  4. Placemaking to restore the environment, improve quality of life and provide access to nature in the city

 READ MORE: CRWA's 4 Principles for Allston Interchange


MassDEP recently submitted the Draft Environmental Impact Report for the new I-90 Interchange for public comment. In February, CRWA submitted comments on the proposal.  

Climate Resilience
The area surrounding the I-90 Allston Interchange is prone to flooding associated with climate change. Green infrastructure is critical to mitigating flooding and reducing the heat island impacts of the interchange. Unfortunately, the proposal submitted by massDOT does not include green infrastructure in a meaningful way. CRWA proposes a constructed wetland and "blue greenways" to manage stormwater and prevent flooding. 

Flooding in Allston

Flood Vulnerability Assessment | Source: MassDOT | View full map

"The DEIR fails to incorporate GI on a meaningful scale. This is a major lost opportunity—the ommision—and, we believe, folly of which will become all too clear in the coming years."

Charles River Ecosystem
Polluted stormwater runoff currently stresses the Charles River ecosystem. The proposed interchange includes large swaths of impervious areas contributing to increased stormwater pollution. The mitigation proposed in  the DEIR is inadequate to address these concerns.Coordination between the many organizations responsible for managing stormwater in the area is necessary to create a workable plan. One of the proposals for the new interchange includes filling a portion of the river to accommodate competing needs in the narrow parcel. Filling the Charles River will harm the diverse fish population and disturb bank habitat. 
Good public transportation is necessary to create a livable neighborhood and to decrease impact to the environment. CRWA believes strongly that West Station, a proposed commuter rail station, must be built in the first phase of the project. The North-South bicycle and pedestrian connections should also be a priority. We need to build the new I-90 interchange for the future, taking into account the expected transition to driverless cars and increased public transportation. 


Topics: Charles River, Climate Change, Climate Change Adaptation, Stormwater, Green Infrastructure, climate change boston, Blue Cities, Low Impact Development

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About Charles River Watershed Association:

One of the country's oldest watershed organizations, Charles River Watershed Association (CRWA) was formed in 1965 in response to public concern about the declining condition of the Charles. Since its earliest days of advocacy, CRWA has figured prominently in major clean-up and watershed protection efforts, working with government officials and citizen groups from 35 Massachusetts watershed towns from Hopkinton to Boston. Initiatives over the last fifty years have dramatically improved the quality of water in the watershed and fundamentally changed approaches to water resource management.