Most people probably don’t think of wetlands much. To people who live in flood-prone areas, however, their absence matters. Some of the rest of us are beginning to catch on to their importance.

Wetlands are disappearing at an alarming rate. Dewetlandization, if I may make up a word, may have a worse environmental impact than deforestation. Fortunately, work to save and restore them has begun.

We have lots of words for various wetlands: swamp, bog, fen, marsh, and more. Some naturally occur. Others, such as rice paddies, are manmade. Whatever the name, water saturates the soil in a wetland. That saturation determines how the soil develops and what kinds of plants and animals live there. Every country on earth has wetlands. Only Antarctica lacks them.

A disproportionately high number of species make their homes in wetlands compared to other forms of land. Not only fish and other water life, but insects, birds, amphibians, mollusks, and an equal variety of plants. Of all endangered species listed by the federal government, a third of them live only in wetlands. About half spend at least some part of their lives there.

Besides making habitats for all these life forms, wetlands perform many valuable functions, such as:

• mitigating or preventing floods
• feeding streams and other bodies of water
• recharging groundwater
• removing pollutants

The importance of healthy wetlands

Until recently, wetlands seemed like wasted space that had to be reclaimed. So people drained swamps, filled in unwanted ponds, and otherwise made the land usable.

In other cases, pumping too much water from underground aquifers depletes wetlands. We read a lot more about deforestation, but wetlands are going away three times faster than forests.

Then we learned why wetlands matter.

• About 90% of the wetlands that existed 300 years ago worldwide have disappeared. These include swamps, peat bogs, coastal marshes, and ponds.
• With fewer natural places for water to collect, heavy rain causes more severe flooding.
• Draining wetlands to make room for crops releases carbon dioxide, a potent greenhouse gas, into the atmosphere.

Governments from federal to state to local have begun to protect wetlands. For example, a bridge reconstruction can take longer than most citizens think reasonable. And it turns out that protecting or reconstructing a wetland causes at least part of the delay.

Some people may still question the value of wetlands. Don’t they attract mosquitos and other disease-carrying insects? Yes, but they also attract frogs and spiders and birds that eat them. A well-functioning wetland can control the insect population much better than any amount of spraying pesticides.

Here are some examples of current wetland restoration projects:

Flood prevention in Charlotte

Charlotte, North Carolina and surrounding Mecklenburg County launched a flood-control program in the 1990s. The county has bought and torn down 460 structures, including houses, apartment complexes, and businesses along the Catawba River and 3,000 miles of creeks. After removing impermeable surfaces, it has planted grasslands to absorb floodwater.

So far, the effort has cost $64 million and saved $28 million in property damage and emergency rescues that haven’t been needed. With every heavy rain, the savings add up. They are eventually expected to reach $300 million, not counting savings from future demolition.

Charlotte-Mecklenburg Storm Water Services analyzes flooding patterns. It appraises properties based on its analysis. It assesses the financial impact of future floods and makes recommendations

When it suggests a buyout, about 85% of homeowners have accepted. Others prefer to stay and intend to elevate their houses. If the houses are already elevated, they intend to elevate them more. They may qualify for grants.

Additionally, some homeowners don’t trust the government. They blame Duke Energy, which operates hydroelectric dams upstream. They think Storm Water Services is merely doing the utility’s bidding. These homeowners have filed a class-action lawsuit against Duke.

At best, however, the buyouts only protect against ordinary rainstorms. In June 2019, an 11-inch downpour upstream from Charlotte caused a catastrophic flood on the Catawba River. It overwhelmed Charlotte’s renewed flood plains.

In 2000, Charlotte-Mecklenburg developed ways of analyzing upstream development to predict where flooding is likely based on development upstream. It can determine flood risk more accurately than the Federal Emergency Management Agency.

Other flood-prone areas of the country have started to follow Charlotte’s example. Congress has even recently passed legislation to make it easier for them to do so.

Restoring the Everglades

The Everglades once covered an area twice as large as New Jersey. When Florida joined the US in 1845, it promptly asked Congress for help in “reclaiming” the “wholly valueless” area. By now, about half of it has been paved over, plowed under, or otherwise “improved.”

Engineers dug canals that carried nutrient-rich water out to sea. That altered coastal salinity and started the toxic algae blooms that now wreak so much havoc. They seeded vast areas with melaleuca, a thirsty Australian tree. They burned native plants. And so the wind carried off the dried-up peat soil. In some places, the ground sank six feet.

In 1928, a hurricane overwhelmed a dike that had been built at Lake Okeechobee.  The resulting flood killed 3,000 people. In response, engineers built a new, taller dike that almost completely surrounds the lake. It severed the lake from the rest of the Everglades. More than 650 billion gallons of freshwater used to flow from the lake into what is now the national park. Today the flow is only about 43% of that.

Now, the Army Corps of Engineers is trying to restore as much of the Everglades as possible. It has to use some of the same canals and dikes formerly built to drain it. It will probably be possible to make what remains more functional but not to restore it to its natural condition.

Native vegetation is coming back. Some native animals have developed a fondness for eating some invasive species. With the demolition of some dams, the Kissimmee River has started flowing through its old channel. Wetlands and the wildlife that thrive there are starting to return. Still, funding remains inadequate. The pace of improvement is too slow to meet threats from rising sea levels and other climate-related problems.

Little wetlands on farms

Not all wetlands cover large areas. Some naturally occur in agricultural fields. Or occurred. As with the Everglades, they once seemed worthless nuisances. Farmers filled them in.

In parts of the upper Midwest (Iowa, Minnesota, the Dakotas), Montana, and three Canadian provinces, heavy rains temporarily fill up thousands of low-lying areas known as prairie potholes. They flush out buried insects. Waterfowl congregate in them to swim and eat the insects. After a while, the ponds dry up, but the ground doesn’t.

Farmers take different attitudes toward these wetlands, which can bog down farm equipment and drown young crops. Some carefully steer around them. Others “improve” the land by draining them and filling them in to make more cropland. Iowa and Minnesota have lost 95-99% of their wetlands.

The federal government is spending hundreds of millions of dollars to persuade farmers to preserve and restore wetlands. Regulations require them to make new ponds to replace drained natural wetlands. So far, however, losses continue to outstrip gains. And permanent ponds don’t fill the same ecological role as the prairie potholes.

In England, farmers, scientists, and conservationists have begun to work together to look for signs of buried ponds. Then they cut down trees and shrubs and dig down till they uncover them. Pond-loving animals soon enough find the pond and move in. Pond-loving plants replace the downed woods.

Wetland restoration, like wetlands themselves, is happening all over the world. Unfortunately, that’s only after 75% of the wetlands that existed at the start of the 20th century disappeared. Only a few farmers have stopped regarding them as obstacles to overcome.

Sources:

Bringing the world’s buried wetlands back from the dead / Matthew Brown and James Brooks, Associated Press. November 5, 2019.
One city’s plan to combat climate change: Bulldoze homes, rebuild paradise / Francis Stead Sellers, Washington Post. November 26, 2019
To save Everglades, guardians fight time – and climate / Allen G. Breed, Daily Journal Online. December 2, 2019
Why are wetlands so important to preserve? / Scientific American. June 19, 2013

Photo credits:
Camp Carroll. US Army photo
Restored marsh. National Park Service photo
Charlotte flood. Some rights reserved by Charlotte Fire Department
Kissimmee River restoration. Public domain from Wikimedia Commons
Prairie pothole restoration. Some rights reserved by USFWS Midwest Region