Iowa’s Forgotten Wetlands
and the Fight to Bring Them Back
by Jim Colbert
“Too soft to walk and too hard to swim” – Tab Benoit, "Muddy Bottom Blues."
When settlers of European origin began moving into Iowa in the early 1800s, wetlands covered an estimated four to six million acres of the state—about 11% of Iowa’s total area. They were especially common in the north-central Des Moines Lobe, the one-sixth of Iowa shaped by the most recent Wisconsin glaciation. When the glacier melted, it left behind a maze of shallow ponds and wetlands scattered across the landscape. One of the few places where you can still see something like this pre-settlement wetland country is the Union Hills Wildlife Management Area near Clear Lake.
Imagine a settler hoping to start a farm in north-central Iowa. They might look out across the wetlands and think, That land’s too soggy to farm—it keeps floods in check and nurtures waterfowl; best to leave it be. Or, just as easily, they might think, If we drained it, we could make it farmland. You can guess which choice was made. In the north-central part of Iowa, 99% of the wetlands were drained using a combination of drainage ditches and field drainage tiles. Iowa currently has about 2,100 miles of drainage ditches and hundreds of thousands of miles of field drainage tiles, with more being installed every year. Statewide, 90-95% of Iowa’s wetlands have been drained. That’s a lot of corn and soybeans produced in what used to be wetlands.
There is growing concern about water quality in Iowa, particularly regarding pollutants like nitrates and the presence of pathogens such as Escherichia coli (E. coli). These concerns, and others such as the presence of insecticides and herbicides in the water, are certainly valid. But quantity has a quality all its own.
Duck decoys in early December
photo by JT Colbert
Human agricultural activities have converted Iowa from a sponge to a storm sewer. Heavy rain and melting snow are not uncommon in Iowa. Water that would have stayed on the landscape, slowly entering streams or evaporating into the atmosphere, is instead quickly transported out of the field. When water is removed from the agricultural landscape using drainage ditches and field drainage tiles, it doesn’t just disappear. It quickly moves to a creek, stream, or river. This rapid increase in the quantity of water results in two things that are of concern to humans: floods and stream bank erosion. The impact of floods is obvious and can be both extensive and expensive. The impact of stream bank erosion is quieter and more insidious—large quantities of the best soil in the world slipping into the murky brown water and beginning a journey to the Gulf of Mexico.
I’ve seen it happen. There’s a soft, muddy splash, and a portion of the bank is now part of the already sediment-laden river. The effect of quickly adding large quantities of water to our rivers and streams can be seen at any time simply by observing the steep, deeply incised banks bordering them.
The rapid transport of water by drainage ditches and field drainage tiles can also, somewhat paradoxically, lead to low water levels in rivers and streams. The reason is that wetlands, by holding and slowly releasing water, can help maintain water levels in rivers and streams during dry periods. Dry periods tend to pose fewer problems for humans—no need to worry about your home or business being flooded. But a dry riverbed can pose huge problems for some species of aquatic animals. Fish tend to be mostly okay—they are mobile, and they can swim downstream where there’s more water. But other, less mobile animals can be in real trouble if the river runs dry. The easiest example is freshwater mussels—Iowa once had a native diversity of 55 species. Because of low-water events, siltation, pollution, and the introduction of nonnative mussel species, only about 40 species remain today—many of them rare or listed as threatened or endangered.
Wetland drainage has a cascade of effects in addition to producing bushels of corn and beans. In the late 1800s or early 1900s, wetlands were generally thought of as “waste areas” that needed to be improved. We’ve since come to realize that wetlands have far more value than that. There are ongoing attempts to restore or reconstruct wetlands throughout the state. A USDA effort, the Conservation Reserve Enhancement Program (CREP) seeks to construct wetlands for water quality improvement and soil erosion control, primarily in north-central Iowa.
An aerial view of a north-central Iowa CREP site in a sea of row crop fields
photo by Mark Lund of Jewell, Iowa
Waterfowl hunting groups such as Ducks Unlimited and Delta Waterfowl help raise funds to produce and protect wetlands, including wetlands where hunting is not allowed, like the Prairie Valley Preserve in Story County.
All of that is good news. Good news for water quality (and quantity). Good news for soil erosion control. Good news for wildlife habitat.
But here’s the bad news. Iowa CREP is designed to enroll 9,000 acres. That sounds like a lot until you remember that Iowa once had four to six million acres of wetland. Nine thousand acres is about 0.2% of the wetlands we once had. That brings us all the way from 1% of our original wetlands in north-central Iowa to 1.2% of our original wetlands.
CREP is a great idea, but to have a meaningful impact, it would need to be scaled up by a lot. Our current efforts to restore wetlands are a poster child for agribusiness that says, “see—we’re doing something good,” but it’s a tiny band-aid slapped on a gaping wound.
We can, and should, do much better. But doing so will require the political will to provide the needed resources. The people of the State of Iowa voted in a mechanism to provide those resources in 2010: The Natural Resources and Outdoor Recreation Trust Fund. Sixteen years later, our representatives in the state legislature have still failed to act. It’s past time to turn good intentions into real restoration—our landscape, our water, and our future depend on it.
How to support wetland restoration in Iowa
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Ask legislators to fund the Natural Resources and Outdoor Recreation Trust.
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Support groups like Ducks Unlimited or Watershed Management Authorities.
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Request a free Nitrate Watch Kit from the Izaak Walton League, measure nitrate in your local waterways, and submit your test results.
Jim Colbert grew up in Cedar Rapids, Iowa, where he spent much of his time in and along Prairie Creek and the Cedar River. He earned a degree in Biology from Iowa State University in 1978, followed by an M.S. and Ph.D. in Botany from the University of Wisconsin-Madison. Jim started his faculty career in 1985 at Colorado State University and returned to Ames in 1988 to join the faculty at Iowa State University. Jim’s research focused on plant and fungal biology. For 15 of his 33 years at Iowa State, he served as the director of the Undergraduate Biology Program. During that time, Jim led the “Skunk River Navy,” an educational stream cleanup initiative that engaged students in hands-on conservation. Jim is an outdoors guy who, at various times, has enjoyed hiking, canoeing, wilderness camping, rock climbing (not anymore!), winter camping, bird watching, moss and lichen watching, fishing, and hunting. He occasionally shares his thoughts about the natural world on Substack (substack.com/@jimcolbert).