Power of Wetlands
Wetlands are nature’s solution to flooding and water quality challenges in Iowa. Find out how we’re conserving and protecting them.
In the last decade, many communities in Iowa have experienced increasingly intense rainfall events resulting in extreme flooding of nearby rivers and streams. These weather events can wreak havoc on communities and require costly repairs to infrastructure. Heavy rainfall is also known to increase soil erosion which can lead to poor water quality, bringing nutrients such as nitrogen and phosphorus into Iowa’s waterways.
It may seem nature is to blame for these challenges, but wetlands show us that nature is also the solution.
What is a Wetland?
In 1979, U.S. Fish and Wildlife Service defined wetlands as:
Lands transitional between terrestrial and aquatic systems where the water table is usually at or near the surface, or the land is covered by shallow water....Wetlands must have one or more of the following three attributes: 1) at least periodically, the land supports predominantly water loving plants; 2) the sub layer is predominantly undrained, wet soil; and 3) the sub layer is saturated with water or covered by shallow water at some time during the growing season of each year.
There are many types of wetlands such as oxbows, marshes, swamps, fens and bogs, but they all provide a myriad of benefits to nature and people. The Nature Conservancy in Iowa is working to locate and conserve wetlands in the Boone River Watershed and Cedar River Watershed, restoring the benefits they once provided on the landscape.
Once an ideal restoration site is located, landowners and TNC staff work with various organizations to secure funding for the project. When funding is made available, planning can begin. Wetland restoration plans might include excavation, breaking of tile lines, or plugging ditches, followed by reseeding of native vegetation.
Wetlands Improve Water Quality
The ability of a wetland to process and filter excess nutrients and sediment depends on how long it can store water before it flows into the nearby stream. Nitrates are a common nutrient necessary for agricultural production but are detrimental to water quality when introduced in excess. Wetlands are an important tool to reach our Iowa Nutrient Reduction Strategy water quality goals. Studies have shown that, on average, oxbows filter 42 percent of excess nutrients from water that flows into them.
Wetlands Increase Flood Storage
Wetlands can slow the flow of stormwater before it enters rivers and streams. When stream flows increase during and after precipitation events, wetlands intercept some of the flood water and slowly release it back into the stream, helping to reduce the peak flows. As precipitation events become more extreme due to climate change, this role of wetlands will become more vital in making Iowa’s landscape more resilient.
Wetlands Provide Wildlife Habitat
Wetlands provide important habitat for young fish to mature before entering the stream as adults. They also offer vital refuge to smaller fish seeking protection from larger, predatory fish. Wetlands are used by migratory birds and waterfowl as feeding grounds and nesting sites. Ducks and geese often begin using wetlands as soon as they begin to form.
Wetlands Provide Outdoor Recreation Opportunities
Wetlands in Iowa are located in urban and rural communities, making them great places for people to connect with nature. Many wetlands in public areas provide outdoor recreation opportunities like, wildlife watching, fishing and paddling! They can also serve an outdoor classroom for students.
Encourage your friends to find opportunities to enjoy nature by sharing one of these Power of Wetlands infographics!
- Nitrate reduction in a reconstructed floodplain oxbow fed by tile drainage
- Nitrate-N load reduction measured in a central Iowa restored oxbow
- Occurrence, abundance and associations of Topeka shiners (Notropis topeka) in restored and unrestored oxbows in Iowa and Minnesota, USA
- Effectiveness of a newly reconstructed floodplain oxbow to reduce NO3-N loads from a spring flood
- Multipurpose Oxbows as a Nitrate Export Reduction Practice in the Agricultural Midwest.