Floods, Ducks, and Development

Urban sprawl in historic river floodplains threatens waterfowl, people, and the environment

© Richard Visker

By Matt Young

Throughout history, North America's rivers have been flyways for waterfowl and other migratory birds. Look at a national map plotted with the locations of where banded ducks have been harvested, and you will clearly see the outlines of the Mississippi, Missouri, Ohio, Illinois, Susquehanna, Platte, Columbia, and other familiar waterways formed by dense clusters of band recovery reports. Rivers not only serve as landmarks that help guide waterfowl during their epic transcontinental migrations but also are directly linked to a variety of valuable wetlands in their adjacent floodplains and watersheds.

From oxbow lakes and bottomland hardwood forests to riverine marshes and wet prairies, floodplain wetlands provide vital habitat for waterfowl, fish, and an abundance of other wildlife. These unique habitats owe their productivity to seasonal fluctuations in water levels influenced by extended periods of wet and dry weather. During the summer, when most rivers and streams recede to low levels, many floodplain wetlands go dry, allowing wet soils and organic matter to consolidate and vegetation to flourish. When floodwaters return—typically during late fall through spring—a profusion of seeds and mast produced by trees and annual vegetation during the growing season becomes available to feeding ducks, geese, and other water birds. The fertile, nutrient-rich waters also teem with aquatic invertebrates, which provide other sustenance for fish and wildlife.

In addition to their habitat value, wetlands help control flooding and purify water supplies. Like giant sponges, wetlands trap and hold sediment-laden runoff in their basins, decreasing the speed and volume of flood water flowing into and through adjacent waterways. At the same time, sediments and other suspended pollutants settle to the bottom, where aquatic plants and microorganisms absorb excess nutrients and remove other contaminants.

During the past two centuries, most of North America's major rivers have been altered for flood control, navigation, irrigation, hydropower, and a variety of other uses. Extensive ditching and dredging and construction of levees, locks, and dams have transformed entire ecosystems by changing stream flows and severing rivers from their former floodplains. Along North America's two largest rivers—the Mississippi and Missouri—the impacts of wetland drainage have been staggering. According to a recent report, roughly 80 percent of the Mississippi's 2,320-mile length has been fixed for navigation, and 90 percent of the river's original floodplain has been cut off from its source.

Farther north along the lower Missouri River, channelization, diking, and bank stabilization projects have shortened the original river channel by more than 50 miles and reduced its surface area by more than 61,000 acres. In fact, the bank-to-bank width of the "wide Missouri" described by Lewis and Clark has been reduced to a relatively straight, 300-foot-wide channel in many places, dramatically reducing the region's natural flood storage capacity. The midstream sandbars, islands, and oxbows that once supported innumerable ducks, geese, and other waterbirds during migration are also largely gone, as well as most of the prairie, forest, and wetlands that once existed in the Missouri's broad floodplain.

Despite these losses, many productive wetlands remain in the Missouri and Mississippi river basins. Some of the best remaining waterfowl habitat is found where these two great rivers meet just north of St. Louis. Located in St. Charles, Lincoln, Pike, and St. Louis counties, this area is known to waterfowl hunters and conservationists as the "Confluence Floodplain." The majority of the Mississippi Flyway's waterfowl—including at least 14 million ducks—pass through the Confluence each year, making this region acre-for-acre one of the most important waterfowl migration areas on the continent. In addition to waterfowl, the region supports hundreds of other species of other birds, fish, mussels, and mammals native to the Mississippi and Missouri river basins.

Steeped in waterfowl hunting tradition, the Confluence is home to more than 200 established duck clubs, including such historic properties as Dardenne, Quivre, and Raccoon Ranch duck clubs, all founded in the early 1800s. Together, these clubs and others manage more than 31,000 acres of wetlands and cropland, comprising one of the largest privately owned waterfowl habitat complexes in the nation. Another 43,000 acres lie within national wildlife refuges, state conservation areas, and tracts owned by the U.S. Army Corps of Engineers. Many of these properties are intensively managed public wetlands and consistently hold large concentrations of waterfowl and provide hunting opportunities for large numbers of hunters from the St. Louis area and beyond.

As its name accurately describes, the Confluence Floodplain is highly susceptible to flooding by the Missouri and Mississippi rivers. In 1993, the region was at the epicenter of the great Midwestern flood that devastated large swaths of America's Heartland. More than 1,000 flood protection levees failed, 70,000 buildings were damaged, and 50 people lost their lives. Estimated damages totaled more than $12 billion, with $3 billion worth of damages occurring in Missouri. At its peak, the Confluence Floodplain held an estimated 260 billion gallons of floodwater, likely saving downtown St. Louis from catastrophic flooding.

For decades the Confluence Floodplain remained a little piece of heaven for waterfowl hunters. But as suburban growth from St. Louis has expanded ever north and westward in recent years, much of the region is now threatened by what until recently would have been an unlikely enemy: urban sprawl. Despite the devastation wrought by the 1993 flood, approximately 4,275 acres in the floodplain have been converted to commercial buildings, factories, and shopping malls. Commercial and residential projects that are either underway, or in the planning stages, threaten to convert another 14,000 additional acres in St. Louis, St. Charles, and Lincoln counties alone. This includes construction of a permanent levee that will allow development of a 1,600-acre business park (known as the Lakeside 370 Project) in close proximity to several historic duck clubs, and planning continues for the expansion of a nearby airport to accommodate jet aircraft. If allowed to proceed, these and other floodplain development will not only directly destroy thousands of acres of valuable farmland, forest, and wetlands, but accompanying light pollution, traffic noise, and other disturbance could sharply limit waterfowl use on adjacent duck clubs and publicly managed wetlands. In addition, new levees will decrease the natural floodwater storage capacity of the floodplain north of St. Louis, and the resulting increased risk of downstream flooding is a serious concern to the majority of residents in the city and surrounding communities.

Leading the fight to save the Confluence Floodplain is a grassroots organization called the Great Rivers Habitat Alliance (GRHA). Founded and currently chaired by Adolphus Busch IV of the Anheuser-Busch brewing family, the GRHA is actively working with a host of state and federal agencies and nonprofit conservation organizations—including Ducks Unlimited—to find ways to protect vital waterfowl habitat and the floodplain as a whole in St. Charles and Lincoln counties. Far from a radical environmental organization, the GRHA draws its support from a broad coalition of waterfowl hunters, farmers, local businesses, and other floodplain residents. One of the GHRA's principal aims is to change Missouri's current floodplain development laws to better protect these important natural areas from exploitation. Another focus is to eliminate tax incentives that unintentionally support floodplain development, incentives that were originally intended to foster urban renewal in inner cities.

Recognizing the region's importance to continental waterfowl populations, Ducks Unlimited has designated the Confluence Floodplain as a priority conservation area. In June 2006, DU signed a memorandum of understanding (MOU) with the GRHA to join the Confluence Floodplain Conservation Partnership, a cooperative effort involving several state and federal agencies and private conservation organizations to conserve wetlands and waterfowl habitat in the region. In recent years, biologists in this partnership have testified at numerous public hearings and submitted written opposition to planned developments, zoning changes, and annexation proposals in the Confluence Floodplain. In addition, the confluence partnership has helped raise public awareness about floodplain conservation issues by sponsoring a leadership summit and by contacting Missouri DU members about upcoming legislation and public hearings.

With the majority of the Confluence Floodplain in private ownership, cooperation with farmers, duck clubs, and other private landowners is essential to meeting DU's conservation objectives in the region. Long-term easements secured through the Wetland Reserve Program (WRP) and Farm and Ranchland Protection Program and perpetual conservation easements donated by private landowners are currently the best tools for preserving the region's waterfowl habitats. In 2003, DU received its first donated conservation easement in the region from the Wilke Land Company. This 635-acre easement completed efforts by conservationists to protect Marias Temps Clair, a historic Missouri River oxbow jointly owned by the Wilke Land Company and the Missouri Department of Conservation (MDC). More recently, DU has accepted two additional conservation easements: a 52-acre easement on the Thousand Oaks Club and 320-acre easement on the Mallard Point Duck Club. Several other duck clubs have expressed interest in donating conservation easements on their properties, and DU is optimistic that many key waterfowl habitats in the region can be protected in this highly cost effective manner forever.

As a partner in the Missouri Agricultural Wetlands Initiative, DU is also working with state and federal agencies and other conservation groups to deliver a variety of programs and practices that demonstrate the compatibility of wetlands and agriculture. For example, DU and the MDC recently joined the Farm Services Agency and the Natural Resources Conservation Service to establish a new conservation practice especially designed to enhance waterfowl habitat on agricultural lands. Known as CP 23 Wetland Restoration "Enhancement," this program provides private landowners with funding, materials, and technical assistance to seasonally flood cropland adjacent to other restored wetlands. In addition, DU partners with government agencies to deliver other agricultural conservation programs, including WRP and Partners for Fish and Wildlife.

Another key component of DU's conservation strategy in the Confluence Floodplain is acquisition and restoration of waterfowl habitat on public land. With funds raised during a tribute event honoring the late August A. Busch Jr., DU recently helped the MDC complete wetland restoration activities on the 4,166-acre B.K. Leach Memorial Conservation Area in Lincoln County. Purchased through a series of acquisitions beginning in 1985, this conservation area consists of a variety of wildlife habitats, including moist-soil wetlands, wet prairie, seasonally flooded cropland, and bottomland forest. Owned and managed by MDC, the area regularly supports large numbers of migrating ducks and geese in the fall and provides excellent public hunting opportunities for waterfowlers. A dedication of this successful project is scheduled for October 6 at B.K. Leach Conservation Area.

The effort to save the Confluence Floodplain from imminent development is only one of many high stakes conservation battles being waged across the continent to conserve North America's floodplains. To succeed in conserving these irreplaceable landscapes, waterfowl hunters, farmers, state and federal agencies, conservation groups, and other stakeholders must work together toward this common goal. Otherwise, history has repeatedly shown that the cost of failure could be disastrous for waterfowl, wetlands, and people.