Andover: Climate Ready Shawsheen - Preparing for Flood Resilience

FY24 MVP Action Grant led by the town of Andover. The town built upon their FY22 & FY23 MVP Action Grant projects to advance a nature-based resilience project at a priority site along the Shawsheen River. The project incorporated additional public outreach to engage community members and advanced preliminary design of a site along the Shawsheen that had been previously identified as a prime candidate for flood storage and/or a restoration project.

Project Details

Project Title

Climate Ready Shawsheen - Preparing for Flood Resilience

Municipality

Andover

MVP Region

Northeast

Award Year

FY2024

Grant Award

 $81,900

Project Length

One year

Community Overview

• Community size and location: The Town of Andover has a population of approximately 36,500 people and is located in Essex County, approximately 20 miles northwest of Boston.
• Environmental Justice and Climate Vulnerable Communities: 
  • While Andover is one of Massachusetts’ wealthier communities, 17.45% of Andover households (over 2,100 households in total) have incomes below $50,000. Andover also contains a large mapped environmental justice (EJ) community north of I-495. This EJ community has a median household income of $176,645 (well above the state median of $85,843) but is mapped as having a 48.3% minority population, with 20.9% of households with language isolation. Portions of this EJ community also overlap with the FEMA floodplains for the Merrimack River and Fish Brook. The EPA’s EJScreen tool identifies additional areas in Andover as meeting demographic indicators of EJ communities. The neighborhood South of I-495 in Shawsheen Heights near the Shawsheen River is mapped as having 13% of its population under the age of 5, putting it at the 93rd percentile nationally for this vulnerable population. The EJScreen tool also indicates that the flood prone area along the Shawsheen River south of the Stevens Street bridge is mapped as having 29% of its population over the age of 64 (88thpercentile); a similarly mapped area occurs just west of North Main Street along the Shawsheen (over 25% of residents over the age of 64; 82nd percentile). One additional area in the same vicinity (along High Street) is mapped as 8% linguistically isolated (82nd percentile).
  • There are three high-density, low-income housing communities along the Shawsheen River at an elevated risk from flooding: Andover Commons (50% of units are reserved for residents with incomes less than 50% of AMI), Marland Place (senior housing), and Frye Circle (a 96-unit Andover Housing Authority property that houses elderly and disabled residents). Marland Place, in particular, is recognized and categorized as having an extreme flood risk by the First Street Foundation’s Flood Factor Tool.
  • Furthermore, ResilientMass indicates that the neighboring downstream City of Lawrence is mapped entirely as EJ communities based on the percentage of minorities, with many areas also mapped for English language isolation and/or income. The median household income for one mapped EJ community in the downtown Lawrence area is $18,882, with a 98.5% minority population, and 50.8% of households with language isolation.
• Unique traits: Andover is an inland town with significant waterbodies including the Shawsheen River, Fosters Pond, Pomps Pond, Haggetts Pond, and the Merrimack River forming the northern border. Architecture found in Andover reflects the Town’s historic past as a mill town, established in part with hydropower from the Shawsheen River. The region’s first powder mill was established in Andover in 1775, and shortly after, paper manufacturing and several textile mills followed. Andover is also known for being the home of Phillips Academy, one of the nation’s oldest incorporated secondary schools. 
  
   

Community Fridge Initiative Display at the 2024 Youth Sustainability Fair Event.
 

Project Description and Goals

• Location: The FY24 project focused on the Lower Shawsheen Soccer Field directly abutting the Shawsheen River in the Town of Andover. The town-owned parcel is within 2 miles of the neighboring City of Lawrence, which is situated downstream in relationship to the parcel.
• Climate impact: The Town’s MVP planning process in 2019 identified flooding as a particular hazard of concern following serious flooding events in May 2006 and March 2010. These major flooding events were triggered by heavy rainfall and caused many roads to close, schools to cancel classes, and residents to evacuate their homes. Climate projections indicated total annual precipitation is expected to increase by 2.34 inches from 2020 to 2049 over historical averages from 1971-2000, while the annual days with precipitation greater than 2 inches are expected to increase by 23%. The FY23 MVP grant awarded to the town focused on quantifying the flood mitigation and other benefits gained from future flood storage and/or restoration on high priority parcels of land along the Shawsheen River, one of which was the town owned Lower Shawsheen Soccer Field. The conceptual design previously developed showed how modifications made to the site would allow for river flow diversion and storage during intense storms, which may help to alleviate flooding on nearby residential properties.
• Goals and tasks:
  • The work in FY24 with the State’s Municipal Vulnerability Program (MVP) built upon on the Town’s prior MVP action actions including the outcomes of the hydrologic and hydraulic (H&H) modeling and conceptual visioning activities from 2022-23 to advance the preliminary design of a flood storage and/or nature-based restoration project at a priority site along the Shawsheen River. The project also incorporated additional public outreach to engage community members in new discussions related to the possible removal of the Ballardvale Dam to ground the conversations in science-based scenarios. It also initiated a new area of social resilience for the town by establishing linkages between food security efforts and climate resilience and focused on the feasibility of acquiring private parcels along the Shawsheen that have been previously identified, prioritized, and studied as prime candidates for flood storage and/or nature-based restoration projects.
  • The project consisted of 4 major tasks:
    • Task 1: Project Kickoff, Management, and Reporting
    • Task 2: Public Involvement and Community Engagement - Community fridge, climate outreach hike
    • Task 3: Preliminary Design of Priority Flood Resilience Site - Site surveying and base mapping, hydrologic and hydraulic modeling and preliminary design
    • Task 4: Private Parcel Acquisition Due Diligence
       

Results and Deliverables

The Climate Ready Shawsheen project progressed the community’s climate resilience work to date in meaningful ways both in terms of technical findings and new engagement strategies.

• Technical results: The Lower Shawsheen Soccer Field conceptual design was refined with more detailed topographic and bathymetric surveys that enhanced the prior hydrologic and hydrologic (H&H) models. This information was then coupled with the Lower Shawsheen Floodable Field conceptual design to arrive at a preliminary engineeringdesign that detailed current and future site elevations, vegetation, and recreational structures. Importantly, the enhanced H&H modeling showed that the floodable field can reduce the Shawsheen River water surface elevation by 1.6 inches under the current 10% storm. However, the improvements would only result in a decrease in the water surface elevation by 0.5 inches in 2070 for the same 10% storm. Moreover, the effects of the improvements attenuate within 5,000 feet downstream from the location of the floodable field.

Preliminary Engineering Design for the Floodable Lower Shawsheen Field in Andover (Fuss & O’Neill).

• Engagement results: 
  • The FY24 MVP project continued effective community engagement strategies, such as the Winter Festival and explored new collaborations both with the Elder Services division of the Town of Andover and the new community fridge initiative. These new engagement partnerships for the Town of Andover’s MVP effort were aimed at informing vulnerable populations – specifically, seniors and food insecure individuals – about the emerging impacts of climate change.
  • Two MVP events took place at the Andover Senior Center. The “Breakfast at the Senior Center” event in February focused on general MVP information and conservation efforts, and the “Andover Dams: Past, Present and Future” event in late May focused on the historic, environmental, and climate resilience significance of Andover’s dams. Both of these events were well attended with many in the audience learning about the MVP project for the first time.
  • Andover’s work with youth also continued in this round of the MVP grant project. Specifically, a high school junior at the Phillips Academy worked closely with the Town as an intern on the community fridge initiative. Community fridges (sometimes called “freedges” or “friendly fridges”) have been embraced by many cities and towns across the world to address both food insecurity and waste, but bolstering social resilience to climate impacts is another good reason to support community fridges. The Conservation Law Foundation (CLF) estimates that nearly a third of power outages in Massachusetts are climate-related and that not all cities and towns experience the same level of outage severity. This outage disparity suggests that a network of community fridges across the state, or community fridges that are supported by backup generators, can be a meaningful social resilience resource particularly if a city or town is more likely to experience an extended power outage. Work with the student intern resulted in a presentation at the April Youth Sustainability Fair and a final study about siting community fridges on municipal parcels.
  • Last but not least, the work in FY24 also made progress towards the goal of acquiring privately owned parcels near the Stevens Street priority site for climate resilience restoration work. Specifically, in coordination with the Town of Andover’s Open Space Task Force, the Sustainability Director worked with the Deputy Town Manager, Planning Director, and Town Counsel on internal due diligence, and initiating appraisals on three privately owned parcels that were previously identified as being integral to the Stevens Street priority site vision (Table 1). The Planning Director has begun communications with parcel owners to discuss the Town’s interest and to assess the owner’s willingness to sell the parcel.

Winter Fest 2024 Event. MVP Poster and Table Display.

Lessons Learned

• Climate resilience and riverine flood mitigation efforts for the Town of Andover will involve a multidecade strategy that seeks to implement multiple nature-based solutions in town. No single site strategy, though necessary, will be sufficient. The work will also likely involve partnerships along the entire watershed, specifically nature-based restoration and conservation collaborations with all the other municipalities upstream of the Shawsheen (including but not limited to Tewksbury, Billerica and Bedford). As more local options, the Town will likely need to look at gray infrastructure updates.
• The Lower Shawsheen floodable field concept was identified as the lowest cost and most feasible among the 3 priority sites in FY23. The floodable concept had many appeals, including continued recreational access, restored riparian buffers that would lower erosion, and new paddling access. However, this project's work showed that implementation of that vision offers modest (1.6 inch) water surface elevation flood protection under current 10-year storm conditions, but less than 1 inch protection by 2070. From previous work, removal of Ballardvale Dam also does not greatly alleviate downstream flood-prone properties, although its removal would de-risk additional harm associated with dam failure during storms and result in meaningful ecological restoration impacts for migratory fish.
• The Town’s strategy on engagement and outreach continues to seek new collaborations and partnerships. Substantial buy-in from stakeholders is needed to pursue a multi-decade and multi-site restoration strategy. Disadvantaged populations within the Town of Andover have been difficult to identify and reach out to in the past. Unlike other communities, the Town of Andover does not have geographically distinct environmental justice (EJ) neighborhoods that are amenable for location-specific outreach campaigns (e.g. door knocking, canvassing, mailing). While the Town of Andover is regarded as an affluent suburb, at least 17% of the population experience economic hardship and self-identify as being food insecure. Working with providers whose missions are directly related to Andover’s disadvantaged populations has been an effective strategy that has broadened the team’s climate resilience education with different audiences. The work with the Senior Center specifically relied on the Elder Services Director’s insight that Andover seniors have deep interests on Andover's history. The MVP team then coupled that interest with a discussion on dams. The work with the community fridge relied on building upon Andover’s existing food insecurity work with a specific climate adaptation lens. This way the climate resilience work builds upon topics and efforts that already have existing champions and networks rather than relying on the audience having a pre-existing interest in climate change.

Partners and Other Support

Technical Scope Partners

• Fuss & O’Neill
• Andover's GIS Division

Engagement Scope Partners

• Andover's Conservation Division
• Elder Services
• AndoverTV
• Andover resident and student intern
• Andover Facilities Department
• Village Food Hub
• Town Manager's Office
• Andover's Planning Division
• Town Counsel
• Open Space Task Force
• Merrimack River Watershed Council
• Merrimack Valley Planning Commission