Building Resilience Across the Watershed

Building Resilience Across the Watershed

Regional Collaboration with the Charles River Flood Model

Flood Predictions Become Flood Solutions

Climate change isn’t coming– it's here. Precipitation during heavy rain events increased by more than 71% between 1985 and 2007 in the northeastern United States. And, as our climate continues to warm, we are expecting even more severe storms.

What does this mean for our watershed? More flooding. A few inches of increase in rainfall across the watershed has the potential to increase the Charles River’s volume by millions of gallons during a heavy storm. And, in our highly urbanized watershed that is home to over a million people; homes, businesses, critical infrastructure, and more are vulnerable to flood damage.

Meet the Charles River Flood Model, a watershed-scale simulation developed with twenty cities & towns that shows how increased precipitation & inland flooding will affect our watershed in the coming years and allows us to test out mitigation solutions to help our communities prepare.

The Building Resilience in the Watershed Initiative is funded by a Municipal Vulnerability Preparedness (MVP) Grant from the Massachusetts Office of Energy and Affairs.

A Regional Collaboration

Flooding doesn’t follow political boundaries– the Charles River Flood Model demonstrates the regional impacts of flooding, including how upstream activities can reduce or exacerbate downstream flooding.

This initiative is a collaboration between Charles River Watershed Association, twenty cities and towns of the Charles River Climate Compact (CRCC), Weston & Sampson, and Communities Responding to Extreme Weather (C.R.E.W). We are working together to respond to the monumental challenges climate change brings to our watershed. With a regional outlook, we're able to better understand inland flooding impacts and determine the most effective solutions.

Do you see your town? Participating communities include Arlington, Dedham, Franklin, Holliston, Medway, Millis, Natick, Needham, Newton, Norfolk, Sherborn, Watertown, Wellesley, Weston, Wrentham, Boston, Cambridge, Dover, Bellingham, Waltham.

VIDEO Building Resilience in the Watershed Initiative with the Charles River Flood Model.

2022 FINAL REPORT

Developing the Flood Model

In 2021, we completed the first phase, the development of the Flood Model for the upper and middle Charles River Watershed. Future climate storm scenarios for the CRFM were determined following the recommendation of the state’s Resilient Mass Action Team (RMAT).

Read the final report for Phase I of Building Resilience in the Watershed, published in June 2021, to learn more about how we developed the model and what we discovered. (Appendix)

LEARN HOW THE MODEL WAS DEVELOPED

Identifying Flood Solutions

In 2022, we completed the second phase, which used the Charles River Flood Model to identify over 50 opportunities for flood mitigation projects and select three priority interventions for flood storage in Waltham, Newton, and Medway.

We updated the flood model to add finer details, additional model runs, and updated the storm event modeling to use Intensity Duration Frequency (IDF) Projections from Cornell.

LEARN ABOUT NATURE-BASED SOLUTIONS

Building Resilience in the Watershed Initiative

The Charles River Flood Model confirms that flooding will be considerably worse by 2070. Today, a so-called "10-year storm", which has a 1% chance of occurring in any given year, causes about 7,660 acres of flooding under current conditions. But, by 2070, due to climate change, the same storm event will flood 10,670 acres, an increase of over 3,000 acres that currently do not flood.

Our watershed is not prepared for this scale of inundation. But, we are rising to this challenge.

Building Resilience in the Watershed Initiative's mission is to bring us to a climate-resilient future. Using the Charles River Flood Model, we have identified priority actions and recommendations to help our watershed adapt to our changing climate. We identified fifty opportunity sites for future flood mitigation projects and developed an accompanying Resilience Toolkit to support local adaptation efforts. Together, we will continue to find solutions for climate change over the coming decades and build resilient communities for the future.

Priority Sites for Flood Storage Concept Designs

The Charles River Flood Model was used to model the impact of three types of nature-based solutions in fifty potential opportunities for flood storage. The nature-based solutions explored were building green stormwater infrastructure, reducing impervious cover, and land conservation and increase in tree canopy. Of the fifty opportunity sites modeled, the project team identified three priority interventions for flood storage and developed concept designs for Oakland Park, Medway, Hardy Pond, Waltham, Albemarle Park, Newton. Learn about the three concept designs below.

Virtual Webinar on Flood Storage Solutions for Hardy Pond, Waltham and Oakland Park, Medway.

Virtual Webinar on Flood Storage Solutions for Albemarle Field, Newton. Ver en español.

Community Engagement & Outreach

For the past two years, we've been working with Communities Responding to Extreme Weather (C.R.E.W.) to bring the Charles River Flood Model to you! From lively virtual events, to detailed surveys, interviews, tabling in your neighborhood, and presenting at in-person community events we've been able to meaningfully connect with hundreds community members and raise awareness about climate preparedness and solutions.

With a focus on educating and empowering our residents, our hyper-local outreach allowed us to reach even more of you in the past year and share our efforts to bring nature-based solutions to your neighborhood.

"We are excited to have led this regional effort,” says Deputy Director Julie Wood. “This is a critical step to taking action as a region to effectively mitigate the expected flooding impacts of climate change. The model provides valuable information that will allow communities to make informed decisions about policy changes and on-the-ground interventions necessary to protect people and nature in the future."

Building Momentum for Climate Resilience

What's next? We will continue to use the Charles River Flood Model to build climate resilience to protect our most vulnerable from the weather extremes of climate change. The Charles River Flood Model is an essential tool for helping our residents and city leaders alike prepare for and respond to flooding. We will continue to use it to call for municipal leaders and elected officials to invest in nature-based solutions, select and design priority flood mitigation interventions to protect our watershed, and educate and empower ordinary watershed residents to prepare for extreme weather.