Five Ways Streams and Wetlands Keep Us and Our Environment Healthy

You may have heard that we’re proposing a rule to clarify which streams and wetlands are protected under the Clean Water Act. Right now, 60 percent of our streams and millions of acres of wetlands lack clear protection from pollution and destruction.

You might not think that your local stream or that wetland in the woods is a big deal, but the water that flows through it could end up hundreds of miles away as someone’s drinking water or where people swim or fish. Streams and wetlands aren’t just a little piece of our water system; they’re the foundation. They generate a large portion of the water that ends up in our lakes and rivers – so what happens upstream affects everything that lies downstream, including the water that flows by our homes and out of our taps.

There are many ways that streams and wetlands keep us and our environment healthy. Here are five of the biggest ones:

1. Filter pollution: Streams and wetlands reduce the pollution that flows to downstream rivers, lakes, bays and coastal waters. They help to trap nitrogen and phosphorus, which can cause environmental issues if they accumulate too much in one place. Small streams have been estimated to remove 20 to 40 percent of the nitrogen that otherwise would go downstream. Research in Oregon’s Rock Creek basin found that headwater streams could retain sediment for more than 110 years – and without the Congaree Bottomland Hardwood Swamp in South Carolina, nearby communities would need to build a $5 million wastewater treatment plant.

 

Photo by U.S. Fish & Wildlife Service

Photo by U.S. Fish & Wildlife Service

 

2. Trap floodwaters: Streams and wetlands can absorb significant amounts of rain and snowmelt before they flood, preventing that water from flowing downstream and putting homes and businesses at risk. The wetlands along the Mississippi River once stored at least 60 days of floodwater. Now they store only 12 days, because most have been filled or drained. As a result, the towns and cities along the river now flood more frequently.

 

Photo by U.S. Army Corps of Engineers

Photo by U.S. Army Corps of Engineers

 

3. Recharge groundwater: Streams and wetlands play a key role in recharging groundwater. A major source of water in rivers in the Southwest is from groundwater released into streams that only flow part of the year. And in the Southeast, South Carolina’s pocosins and hardwood swamps are estimated to store 45.8 billion gallons of water, or enough to fill 70,000 Olympic-size swimming pools.

 

Photo by EPA

Photo by EPA

 

4. Provide drinking water: Streams and wetlands play a critical role in providing clean drinking water by ensuring a continuous flow of water to surface waters and helping recharge underground aquifers. In the continental United States, 60 percent of streams only flow after rain or in certain times of the year. Approximately 117 million people – one in three Americans – get drinking water from public systems that rely on these streams.

 

5. Provide habitat for fish and wildlife: More than one-third of our country’s threatened and endangered species live only in wetlands, and nearly half use wetlands at some point in their lives. For many animals and plants, like wood ducks, muskrat, cattails and swamp rose, inland wetlands are the only places they can live. For others, such as striped bass, peregrine falcons, otters, black bears, raccoons and deer, wetlands provide important food, water or shelter.

Photo by U.S. Fish & Wildlife Service

Photo by U.S. Fish & Wildlife Service

 

Editor's Note: The views expressed here are intended to explain EPA policy. They do not change anyone's rights or obligations. You may share this post. However, please do not change the title or the content, or remove EPA’s identity as the author. If you do make substantive changes, please do not attribute the edited title or content to EPA or the author.

EPA's official web site is www.epa.gov. Some links on this page may redirect users from the EPA website to specific content on a non-EPA, third-party site. In doing so, EPA is directing you only to the specific content referenced at the time of publication, not to any other content that may appear on the same webpage or elsewhere on the third-party site, or be added at a later date.

EPA is providing this link for informational purposes only. EPA cannot attest to the accuracy of non-EPA information provided by any third-party sites or any other linked site. EPA does not endorse any non-government websites, companies, internet applications or any policies or information expressed therein.