Boston has 47 miles of coastline. Roughly one-sixth of the city is built on filled tidelands. More than 40 percent of residents live with the risk of flooding. And climate scientists expect sea levels in Boston Harbor to rise several feet in the coming decades.
To state the obvious: These numbers create a potential recipe for disaster.
But city and state leaders, along with their federal partners, are not ignoring the risks of climate change as glaciers melt and oceans rise. With feedback from Boston, the US Army Corps of Engineers recently wrapped up a four-year draft study to develop a network of flood gates, levees, and flood walls to fortify the most vulnerable areas of the city. The estimated cost: $10 billion.
If Congress authorizes the funding, which is unlikely with President Trump in office, Washington would cover up to 65 percent of the costs. Assuming the money eventually comes through, the city, state, and private sector need to find a way to come up with the rest and not let these federal funds slide by.
Flooding is not a far-off problem. Parts of the city are already regularly inundated, such as Morrissey Boulevard in Dorchester. As sea levels rise, coastal protections will need to be in place by the 2030s to protect Boston’s most vulnerable seafront areas, including Charlestown, downtown, Dorchester, East Boston, and South Boston.
Both levees and seawalls are built near a water’s edge to hold back floodwaters. Levees are typically made from natural earth, such as dirt and clay, and look more like a small sloped hill. They’re most often used along rivers. Seawalls are flat panels of concrete built near a shoreline. Levees are cheaper to build but require more maintenance.
The city and state have long been understandably reluctant to fund expensive climate resiliency projects from their cash-strapped budgets. But after a decade of careful study to determine the best paths forward, now is the time for decisive action to come up with a funding stream.
“Doing nothing is not a viable option,” Lieutenant Colonel David MacPhail, deputy commander of the New England District of the US Army Corps of Engineers, said in a statement. “Without action, the costs to public safety and economic vitality from coastal flooding will only be compounded.”
The Army Corps estimated that Boston could face more than $54 billion in losses between 2040 and 2090 if it fails to act. Hospitals, businesses, critical roads, tunnels, and the airport would all be vulnerable to repeat flooding.
Put another way, every dollar invested in Boston’s resilience will save future residents, businesses, and the public sector at least $4 in avoided disaster losses.
Boston’s climate resilience funding model has long relied on private developers. In the boom before the pandemic, city officials often convinced developers building apartments, offices, hotels, and restaurants to include infrastructure improvements to protect low-lying areas from floods.
City Councilor Gabriela Coletta Zapata has said the city’s climate adaptation projects are Boston’s next ”Big Dig” and has called for waterfront property owners to pool money for them.
She’s right. Private investment must remain part of the equation, especially for developers who built in areas like the Seaport where the future flood risks were well known. Still, leaving future climate protections to the whims of the real estate market is a risky strategy. Reliable local government funding sources must also be identified.
The Boston Green Ribbon Commission, a group of business and civic leaders, is developing a decades-long fundraising plan. In the next 12 to 15 months, a panel expects to identify funding and financing options from public and private sources.
Erecting walls and levees also offers a chance to revitalize the coastline, as city officials have said they intend to do, by adding parks, boardwalks, and coastal walkways along the shoreline. In the San Francisco Bay Area, levees along the water have become well-used cycling, walking, and running paths, while affording flood protections to neighborhoods.
Even with a $10 billion investment, Boston would not be impregnable to the most severe storms. Nature-based solutions, which are more cost effective than erecting concrete barriers, should be expanded in the city’s coastal protections. Those include planting oyster reefs to break wave energy, restoring salt marshes, and incorporating green spaces to take in excess waters.
The state has a good track record of supporting these types of solutions. The federal government does not. Historically, the Army Corps has tried to tame nature with concrete and steel. That engrained thinking has been shifting and needs to continue to evolve.
When it comes to protecting Boston from rising tides, “We need everything in the toolbox,” the Nature Conservancy told the editorial board.
Even if fortifications are built, we can’t be lulled into a false sense of security. In many ways, putting up protective barriers and incorporating nature-based solutions is the easier part. There remains a distinct probability that today’s investments will afford insufficient protection against sea level rise if planet-warming emissions aren’t checked.
New Englanders can’t stop climate change alone, but we must continue to lead by example in curbing our dependence on fossil fuels. This is not a Red state vs. Blue state issue. Rising tides don’t care about personal politics.
Editorials represent the views of the Boston Globe Editorial Board. Follow us @GlobeOpinion.