Wetlands and Water

By capturing, storing, and filtering water, wetlands provide important benefits for wildlife and people

© DOUGSTEINKE.COM

By Jennifer Boudart

Ducks Unlimited conserves, restores, and manages wetlands and associated habitats for North America’s waterfowl. These habitats also benefit other wildlife and people. The first part of DU’s mission statement makes clear its primary focus: securing wetland habitats for the benefit of waterfowl. But that second part shouldn’t be overlooked—in particular, the benefits that wetlands provide to people. Many of these benefits, which are also called “ecosystem services,” result from the unique way that various types of wetlands interact with water that is moving over the landscape. DU recognizes the value of these ecosystem services and works to enhance them while pursuing its conservation mission for waterfowl. Following are five important water-related benefits provided by wetlands.

1. Clean Water

As water passes through them, wetlands naturally filter out sediments, excess nutrients, and chemical pollutants. Freshwater wetlands can serve as natural water treatment systems that purify water ultimately used for drinking, manufacturing, and recreation, and DU designs wetland projects for this purpose. A great example is H2Ohio, a statewide water quality program introduced by Ohio Governor Mike DeWine that focuses in part on reducing algae blooms in Lake Erie that are primarily caused by excess phosphorous in agricultural runoff. These algae blooms negatively impact drinking water supplied by the lake and activities such as boating and fishing. Work is happening on multiple fronts to reduce inputs of phosphorous into Lake Erie, including the creation or restoration of phosphorous-filtering wetlands.

DU and the Ohio Department of Natural Resources are among many partners participating in H2Ohio. To date, DU has received funding for seven wetland filtration projects, which will also provide important breeding and migration habitat for mallards and other duck species. One of the projects completed through this initiative improved a 23-acre wetland that DU and its partners had previously restored in cooperation with the landowner through the Lake Erie Conservation Reserve Enhancement Program. Money from H2Ohio and the Great Lakes Fish and Wildlife Restoration Act funded additional work to install a pump that diverts runoff from 62 acres of adjacent agricultural land into the wetland before it flows into Packer Creek, which ultimately flows into the western basin of Lake Erie.

2. Reduced Flooding

Wetlands along rivers and streams reduce flood impacts by allowing floodwaters to slow down, spread out, and lose energy. The excess water is temporarily stored before gradually being released back into adjacent waterways. Unfortunately, changes in land use have eliminated many floodplain wetlands, not only increasing threats from flooding but also reducing important habitat for migrating and wintering waterfowl. DU projects involve designing and installing infrastructure that allows land managers to create ideal habitat conditions by flooding or draining wetland units individually.

That same water-control infrastructure can help store water to mitigate heavy flooding. A dramatic example took place in Michigan in early 2020, when heavy rains caused two dams to fail on the Tittabawassee River. Thousands of residents were put in harm’s way as water rushed downstream toward Saginaw Bay and Lake Huron. Managers at the Shiawassee National Wildlife Refuge took action to contain as much of the oncoming water as possible. This included fully opening all the pipes on Maankiki Marsh, a project DU had completed with the US Fish and Wildlife Service (USFWS) to restore wetlands on nearly two square miles of previously drained land along the Shiawassee River. The entire 1,000-acre marsh filled with floodwater 10 feet deep, as did the rest of the refuge, and significantly reduced flood damage in Saginaw County.

Photo © DOUGSTEINKE.COM

3. Coastal Resilience

Coastal wetlands provide habitat for millions of migrating waterfowl as well as wading birds, shorebirds, fish, and other wildlife. These wetlands naturally buffer coastal landscapes from hurricanes and severe storms by reducing the energy of storm surges and absorbing floodwaters. Consequently, they protect property and infrastructure as well as industries such as recreation and tourism, commercial fisheries, shipping, and energy. Saltwater intrusion, sea-level rise, erosion, and other factors threaten coastal marshes in Texas and Louisiana. Making these coastlines more resilient is key to DU’s Gulf Coast Initiative.

DU and its partners are currently working to complete a living shoreline project at Anahuac National Wildlife Refuge in Texas. Installing breakwaters along the Gulf Intracoastal Waterway, which is adjacent to the refuge, will protect the refuge’s marshes from further erosion. These efforts will also improve navigation efficiency and safety for barges that carry more than 100 million tons of cargo annually along this part of the waterway. Funding for the project was provided by the USFWS and the Texas General Land Office through the Coastal Erosion Planning and Response Act.

4. Groundwater Recharge

Water from wetlands can help replenish underlying aquifers as it slowly seeps into soil. Aquifers are a vital source of water for homes, businesses, and farms in arid or semiarid states. For example, the South Platte River and its underlying alluvial aquifer provide water to cities and towns along Colorado’s Front Range and to agricultural communities across the northeastern part of the state. The river and its associated wetlands and sloughs also support millions of migrating ducks and geese. Unfortunately, rapid population growth and changes in irrigation practices have squeezed the water supply to the extent that the river sometimes runs dry in places.

DU works with farmers, water providers, public land managers, and other partners to create “recharge” wetlands that add water back to the South Platte when it’s needed most. River water is diverted into these wetlands in winter or early spring, when irrigation demand is low and waterfowl use is high. Water then seeps into the aquifer and slowly makes its way back to the river channel, augmenting water supplies during the summer irrigation season. Tamarack Ranch State Wildlife Area, which spans 15 miles of the South Platte River, features recharge wetlands created by DU with financial support from public partners as well as private corporations, such as Cargill, that are interested in maintaining water security. This wetland habitat also provides opportunities for hunting and other forms of recreation.

5. Water Efficiency

Water efficiency is an important component of DU’s work, especially in arid western states where wetlands depend on allocated water. This is the case in California, where it can be difficult to supply enough water to support a significant human population, a globally important agricultural industry, and vital habitats for waterfowl and other wildlife. To meet these demands, water is delivered to users through an elaborate system of water storage and conveyance infrastructure. To provide water for wildlife, DU engineers help improve water conveyance infrastructure that benefits other water consumers too.

In California’s Central Valley, DU is nearing completion of a $52 million project to ensure that Gray Lodge Wildlife Area receives its full allocation of water. The wildlife area and surrounding agricultural lands provide vital habitat for wintering waterfowl in the Pacific Flyway. DU was contracted by the Biggs–West Gridley Water District, which had completed a first phase of improvements, to address problems related to capacity and timing of water delivery. DU’s work to upgrade canals, levees, and other infrastructure will benefit all the system’s users.