Trust Magazine

To Mitigate Flooding, States and Communities Increasingly Turn to Nature

Wetlands, marshes, and other natural features can reduce risk and save money

Rocks, grass, and native vegetation bordering Milwaukee’s Lincoln Creek allow rainwater to soak into the ground. The creek used to be lined with concrete, and it flooded more than 4,000 times before the human-made material was replaced with natural buffers.
Milwaukee Metropolitan Sewerage District

Communities and states are increasingly recognizing that smart conservation can help people as well as the natural world. One example of this is the growing adoption of nature-based solutions to mitigate flooding. Such strategies include replacing impervious surfaces such as asphalt with gravel to allow rainwater to seep into the ground, converting developed areas in flood plains to open green space to absorb floodwaters, and preserving and restoring “living shorelines”—dunes, wetlands, mangrove forests, and other natural features—which diffuse rising waters and help blunt the force of storm-driven waves.

In many cases, such “green” and “blue” infrastructure reduces long-term operations and maintenance costs for local and state governments compared with levees, dams, floodgates, and other hard infrastructure. In one example, research shows that living shorelines are often more cost-effective than traditional shoreline armoring, such as bulkheads and seawalls, in protecting communities from flooding.

Flood-related disasters are the costliest in the U.S., accounting for more than $900 billion in damage and economic losses—across all 50 states—since 2000. In response, community leaders and policymakers are developing an array of projects, policies, and financial incentives to harness the power of nature to manage floodwaters.

Research shows that living shorelines are often more cost-effective than traditional shoreline armoring, such as bulkheads and seawalls, in protecting communities from flooding.

For example, in the 1990s, as Milwaukee experienced population growth, increased development, and more frequent climate impacts, its leaders developed an innovative approach to combat repeated floods. The Milwaukee Metropolitan Sewerage District (MMSD) began removing much of the concrete lining from local streams and rivers that had been installed decades earlier, and exacerbated poor stormwater runoff conditions, and replaced it with natural materials.

MMSD spent $120 million to restore Lincoln Creek, a 9-mile waterway in a densely populated section of Milwaukee that had flooded more than 4,000 times since the lining was installed. A combination of grass, rocks, and native vegetation replaced the concrete, and today the creek is less likely to spill over its banks during heavy rainfalls, all while the natural buffers provide habitat for wildlife.

Lincoln Creek runs 9 miles through a densely populated section of the city.
Milwaukee Metropolitan Sewerage District

Maryland, a state with more than 7,000 miles of shoreline, is vulnerable to both storm surge and sea level rise. In 2013, regulations for the Living Shoreline Protection Act, which requires coastal property owners to use natural solutions to prevent erosion, were implemented. This requires property owners to apply for a tidal wetlands license before starting construction that might affect the shoreline and to include a plan for implementing natural features. These features are intended to provide natural defenses against both tropical surge events and high tides.

In Virginia, flooding is the most common and costly natural disaster, affecting every corner of the state, disrupting lives, damaging homes and businesses, and costing tens of millions of dollars in recovery efforts annually. In 2020, the state government created the Virginia Community Flood Preparedness Fund, giving priority to nature-based projects to reduce flood risk. The fund is capitalized through the state’s participation in the Regional Greenhouse Gas Initiative (RGGI), which limits collective carbon dioxide emissions from electric power plants and sells CO2 allowances through a quarterly auction, thus reducing overall pollution and generating revenue for community investment. In March, the first-quarter auction generated more than $43 million, of which $19 million will be allocated to the fund. The first round of grants is expected to be available by this summer.

By turning to natural ecosystems to address flooding, governments at all levels can improve community safety, save taxpayers money, and help restore the health of natural ecosystems.

Mathew Sanders is a senior manager with The Pew Charitable Trusts’ flood-prepared communities initiative.

This article was previously published on pewtrusts.org and appears in this issue of Trust Magazine.

Return on Investment The Pandemic's Troubling Impact on Philadelphia
The front facade of the Supreme Court of the United States in Washington, DC.
ian-hutchinson-U8WfiRpsQ7Y-unsplash.jpg_master

Agenda for America

Resources for federal, state, and local decision-makers

Quick View

Data-driven policymaking is not just a tool for finding new solutions for emerging challenges, it makes government more effective and better able to serve the public interest.

Lightbulbs
Lightbulbs

States of Innovation

Data-driven state policy innovations across America

Quick View

Data-driven policymaking is not just a tool for finding new solutions for difficult challenges. When states serve their traditional role as laboratories of innovation, they increase the American people’s confidence that the government they choose—no matter the size—can be effective, responsive, and in the public interest.

Trend Magazine
Trend Magazine
Trend Magazine

Sometimes Water Should Be Left Where It Is

Quick View
Trend Magazine

In March 2018, torrential rains poured over the Australian Outback in the state of Queensland. The water pooled and began dispersing into rivulets for a long march to the Lake Eyre basin, which bottoms out 50 feet below sea level—the lowest point in the country. Over the course of weeks, the runoff filled innumerable channels that in turn fed into three river basins—the Georgina, Diamantina, and Cooper Creek—and advanced toward Lake Eyre like one massive aquatic organism, transforming a sweltering and inhospitable landscape into one alive with plants, wildlife, and birdsong.

Woman walking in floodwater
Woman walking in floodwater
Opinion

Virginia's New Flood-Preparedness Program Is a Statewide Win

Quick View
Opinion

Crafted this past legislative session by the General Assembly and Governor Ralph Northam, the law creates the Virginia Community Flood Preparedness Fund, which will provide flood-prone communities with low-interest loans and grants to carry out projects that help reduce flood damage and the costs associated with recovery.