Iowa’s Water History
How water, geology, and agriculture shaped the Iowa we know today
How Did We Get Here?
For those who live here, Iowa’s landscape – corn and soybean fields, tree-flanked streams, and the occasional wetland or prairie – all just feel like, well, home. But how did our current landscape, and the water and soil that power its agricultural productivity come to be?
For the answer, let’s look into the distant (and not so distant) past.
A Land Shaped by Glaciers
12,000 years ago – 1800 CE
Iowa’s farmland and surface streams are built upon thousands of years’ worth of sediment left by massive ice sheets that expanded and contracted across the landscape.
1 million – 12,000 Years Ago
This period spans hundreds of thousands of years of glacial advance and retreat across Iowa. Each round of glaciers left behind ground-up minerals and soils, called till, and shaped Iowa’s watersheds.
12,000 Years Ago – 1800 CE
The last ice sheet in Iowa retreats as the climate warms, setting the stage for the tallgrass prairie, oak savannas and fertile wetlands encountered by Native Americans and, later, Euro-American settlers.
Iowa Landforms
- Alluvial Plains
- Loess Hills
- Northwest Iowa Plains
- Des Moines Lobe
- Iowa Erosion Surface
- Paleozoic Plateau
- Southern Iowa Drift Plains
From Frontier to Farmland
1803 – 1870
New settlers converted the prairie-dominated frontier into productive farmland for their own survival and in response to governmental, economic, and cultural incentives. Practices introduced in this period, like tillage and wetland drainage, were effective ways for farmers and their families to make a living.
1803-1840
Louisiana Purchase and opening for settlement: The U.S. buys a huge swath of land west of the Mississippi River from France, including what is now Iowa. Official settlement of the area began in the 1830s.
1846
Iowa is admitted as a U.S. state. Early farmers practice tillage and wetland drainage to effectively grow food and make a living.
1850-1870
Widespread settlement and ag production statewide. Farmers use new horse-powered equipment to step up production to meet growing market and government demands.
1850s vs 2016 Landcover of Iowa
Widespread settlement and ag production statewide. Farmers use new horse-powered equipment to step up production to meet growing market and government demands.
A Century of Change
1900s
The 20th century brought new challenges for Iowa ag, as well as powerful technological and scientific advancements. New machinery, plant genetics, and readily-available fertilizer combined with established ag practices – led to unprecedented production, but at growing environmental cost.
1909
The Haber Process is discovered, leading to industrial-scale nitrogen fertilizer production
1930s
Intense tillage and drought lead to the Dust Bowl. In one year alone, experts estimate 850 million tons of topsoil is blown off the Plains.Unemployment reaches 25%. But devastation leads to change in 1933.
1933s
In 1933, the National Erosion Service (now known as NRCS) is created to help farmers reduce tillage. Today, nearly 16 million Iowa farm acres use conservation tillage or no-till.
1941-1945
Iowa’s own Norman Borlaug begins his agri-science career which led to high-yield, disease-resistant hybrid crop genetics and ushered in the “Green Revolution” of modern agriculture. Meanwhile, the federal government
1950s-1970
New tech fuels rapid growth in farm size, output and competition. As before, farmers had to keep up with government and market demands, and in the 1970s many took on debt to keep their farms viable.
1980s
Massive debt and market downturns cause a historic crash of the farm economy. For many farmers, the help that came with the 1985 Farm Bill was too little, too late.
1997
The Mississippi River/Gulf of Mexico Watershed Nutrient Task Force is established to address the growing Dead Zone in the northern Gulf of Mexico, fueled by nutrient runoff.
New challenges, new opportunities
2000s-Present
The 21st century has seen continued science and tech advances alongside a changing climate and rising water quality concerns. We’ve learned that some long-standing practices that helped Iowa farmers meet society’s demands came with drawbacks, like nutrient loss and soil erosion.
In response, we’ve seen powerful partnerships emerge – between urban and rural communities, and between the public and private sectors – to improve water quality for all Iowans and our downstream neighbors.
2008
The Mississippi River/Gulf of Mexico Watershed Nutrient Task Force calls on each of the 12 Mississippi River border states to develop a nutrient reduction strategy.
2013
The Iowa Nutrient Reduction Strategy (NRS) is established by the The Iowa Department of Agriculture and Land Stewardship, Iowa Department of Natural Resources, and Iowa State University.
2014
The Iowa Agriculture Water Alliance is formed by the Iowa Corn, Pork, and Soybean commodity groups to bring together Iowa farmers, businesses, non-profits, and government partners in support of NRS goals.
2023
As the first decade of the Iowa NRS closes, Iowa farmers plant a record 3.84 million acres of cover crops, while high-impact water quality practices expand across the state using the Batch and Build approach.
2024
IAWA celebrates 10 years of building powerful partnerships to support the Iowa Nutrient Reduction Strategy.
What’s next? You decide.
Our water, our responsibility
Iowa’s water and agricultural history is defined by times of change, challenge, adaptation, and success. While there is still much water quality improvement work to be done by all of us, we have full faith that our partners, and all of our fellow Iowans, are up to the task.
Want to get involved in water quality improvement? Now is an excellent time to jump in – you don’t have to farm, work in agronomy or have a degree in hydrology to make a difference. Your county’s Soil and Water Conservation District office is a great place to start learning about efforts in your neighborhood.