Floodplains / Bottomlands / Wetlands:
Vital to Humans and Wildlife

Carol Roberts

Bottomlands by Carol Roberts
Cedar Creek during heavy spring rains (Carol Roberts)

Cedar Creek flows into the St. Joseph River, which is the source of Fort Wayne’s drinking water. The St. Joseph then flows into the Maumee River, which eventually flows through Toledo, Ohio, into Lake Erie, becoming part of the Great Lakes system.

From County Road 68 in Dekalb County to its confluence with the St. Joseph River below Cedarville in Allen County, Cedar Creek is designated under Indiana’s Natural, Scenic, and Recreational Rivers Act. This segment of Cedar Creek carves an 82-foot-deep canyon, created by rushing waters that cut through glacial deposits (moraine) and pirated water from the Wabash Basin in the west into the Maumee system in the east.

After only a day or night of snowmelt or heavy rain, Cedar Creek may rise rapidly, spill over its banks, fill surrounding bottomlands for several days, then withdraw into its banks again, leaving behind a rich layer of sand and silt. These regular floods create the magnificently forested meandering floodplains fringing each side of the creek’s channel.

Geologists say these floodplains/bottomlands/ephemeral wetlands are “a vital geomorphic feature”—an integral part of healthy rivers and creeks, as well as nature’s flood protection. The floodplains mitigate flood damage, replenish groundwater, filter pollutants, and provide habitat for an incredible diversity of plants and animals. They are also great places for people to learn about and enjoy nature.

Although Indiana has designated Cedar Creek an Outstanding State Resource Water (OSRW), it is impaired by pollutants and clouded by sediments (visible in the sometimes muddy/turbidity of Cedar Creek, pictured above) caused primarily by human activities such as
  • chemicals applied to agricultural fields,
  • fertilizers and pesticides applied to lawns and gardens,
  • industrial waste,
  • construction activities that disturb soil.
These nonpoint source sediments and pollutants wash into roadside storm drains or ditches and then into Cedar Creek and its bottomlands.

Cedar Creek’s relative health is due to its many entrenched natural meanders, river oxbows, and numerous points of groundwater recharge. Flowing freely across the valley floor, the creek changes course in response to natural obstacles such as fallen trees and branches, creating riffles, glides, and shoals that aerate and clean its waters.

People benefit from healthy floodplains/bottomlands/wetlands. While rivers and streams can threaten the structures that humans build, the best way to keep communities safe from floods is to give rivers and streams room to spread out—to flood naturally. (Natural flood control is the primary function of Fort Wayne’s Headwaters Park.) Protecting, nurturing, and restoring floodplains such as Cedar Creek’s allows them to serve as gigantic sponges that soak up huge amounts of rainwater, then release it gradually. This absorption helps prevent flooding downstream--and downtown.

Floodplains/bottomlands/wetlands are essential to the health of the creek and its inhabitants. Regular floods inundating Cedar Creek’s bottomlands recharge groundwater, help maintain water quality by filtering human pollutants, and create the wetlands and floodplain forests that nurture native plants and wildlife. Diverse wildlife includes mammals such as beaver, mink, muskrat, otter; waterfowl such as wood ducks and herons (photo); birds such as barred owls, pileated woodpeckers, and belted kingfishers (photo); and aquatic species such as frogs, salamanders, and freshwater mussels that filter the water.

Cedar Creek’s ephemeral wetlands--overflowing in times of high water and drying up in summer/fall-- provide critical links to other wetlands and to some wildlife populations. Some frogs and salamanders that spend most of their lives in upland areas come to ephemeral wetlands only to breed and lay eggs. Why? Because in these usually small, isolated areas, their eggs will not be eaten by fish. These wetlands are also home to chorus frogs and tree frogs (spring peepers) whose songs are a welcome first sign of spring.

Native plants anchoring the creek’s bottomlands and banks include Indiana’s magnificent, iconic sycamore trees. While preventing soil erosion into the creek, the sycamores provide homes for animals, and birds such as the great blue herons that nest in their high branches.

Bottomlands by 
Heather Baker
Ephemeral wetlands near Cedar Creek, Dustin Nature Preserve - ACRES (Heather Baker)

The Cedar Creek valley’s remarkable species’ diversity is dependent upon undisturbed terrain, old-growth undisturbed forest, and floodplain and wetland aquatic habitats. In Cedar Creek and its prolific bottomlands, everything natural works together for good.

  • Wood duck males are “the most highly colored North American Duck,” red-eyed, beautiful. Winter/spring plumage includes “a crest splashed with blue and green feathers tinged with iridescent sparkles”(Peterson and Audubon). They need the clean open waters and tall lush vegetation in Cedar Creek’s undisturbed, forested bottomlands. Rather small and shy, wood ducks slip into spaces in trees and bottomland tangles searching for seeds from land and water (acorn, beechnut, sedge), sometimes eating frogs, dragonflies, beetles, and mosquitoes.

    Wood ducks nest in tree cavities as high as 50 feet over Cedar Creek. Lucky the humans who witness their spectacular spring splashdown: Just a few days after the mother has warmed and dried her newly hatched, downy ducklings, she calls them down to the water, and they return her calls. Though they cannot fly, they leap, one by one, from the nest, landing almost always unharmed in the creek or on its banks. (Yes—a leap of faith in the duck world.)

Wood Duck by 
Carol Roberts
Wood Duck (Wikipedia)
  • Except for Sandhill Cranes, the keen-eyed, sharp-beaked Great Blue Herons are our Northern states’ largest wading bird: about four feet tall with a 72” wingspan. They fly majestically and gracefully over Cedar Creek, heads and long necks folded back, trailing their long legs. Landing in shallow places (sometimes in Cedar Creek’s tributary, Willow Creek), they patiently, motionlessly—wait, wait. . . . . . wait— to grab with their scissor-like bills the fish and frogs (that have eaten the creek’s insects, which in turn have eaten the creek’s plants. . . .).

    Great Blue Herons build nests 100 feet up in sycamores over Cedar Creek. Chicks leave the nest after 8 weeks of parental care. ACRES Land Trust has permanently protected two of their nesting areas on Cedar Creek.

Grea Blue Heron by 
Kirsten Roberts
Great Blue Heron (Kirsten Roberts)
  • Belted Kingfishers are named for their blue-gray belts (breast bands). The male has one belt, the female, two. With her rusty-brown flanks, the female is also more colorful than the male (an anomaly in birds). Both have big heads with a ragged crest.

    Except in breeding season, kingfishers are solitary, unwilling to tolerate other kingfishers on their waters. I have watched a kingfisher on its regular perch (a high branch overhanging Cedar Creek that it repeatedly returns to) plunge in headfirst to catch fish. Between this perch and other perches, it regularly patrols its domain, hunting day and night for small fish, crayfish, shellfish, insects, mice—even wild fruits.

    While wood ducks and great blue herons construct nests high above the creek, kingfishers aim low. In a bank near water, steep enough to be relatively vegetation-free, they excavate a 3 to 4 inch diameter, upward-sloping burrow 4 to 5 feet long. The burrow is just big enough for a 4 inch-diameter nest in which to lay 5 to 8 white eggs.

    Kingfishers alternate uneven wing beats with a long, low glide as they fly close to Cedar Creek. You’ll immediately know it’s a kingfisher when you hear a rattling, rusty-hinged voice echoing eerily, wildly over the water.
Belted King Fisher by 
Carol Roberts
Belted King Fisher (Carol Roberts)

"The loss of habitat and habitat fragmentation has had large negative effects on biodiversity. Remaining available habitat along the St. Joseph River and its tributaries consists of isolated woodlots, isolated wetlands, public and private natural areas, riparian areas, aquatic habitat, and fallow land.

Agricultural crops, which require the removal of all native vegetation, are the dominant land use in the watershed. Residential development, such as the rapid development of northern Allen County and southern DeKalb County, often results in the the loss of native vegetation.

The removal of vegetation from the banks of the river and its tributaries contributes to bank erosion, and the associated sediments make the water more turbid. Increased turbidity and lack of shade allow more energy from the sun to be absorbed by the water and increase its temperature. The primary effects of thermal pollution are direct thermal shock and changes in dissolved oxygen levels, both of which are harmful to aquatic organisms."

State of the River - St. Joseph River Watershed Initiative (SJRWI), March 2011

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