Iowa’s Huge Population Problem

Update: Chris Jones updated some details about the population and fecal waste issues. Please follow this link for his post 50 Shades of Brown.


My state of Iowa has a human population of 3.16 million (2018). Demographics are here. Des Moines is the most populous city with over 210,000 residents, then Cedar Rapids (130,405) and Davenport (102,582). The rest of the state is mostly small towns and rural. The many river and stream watersheds are outlined in the following image with the human population noted.

Dan Gilles | Water Resources Engineer | Iowa Flood Center

Why do I say the state has a huge population problem? It is because of the large numbers of animals grown in these watersheds. There are about 20-24 million hogs, 250,000 dairy cattle, 1.8 million beef cattle, 80 million laying chickens, and 4.7 million turkeys. Not included are the sheep, goats, horses, deer or Canada geese. These animals create a heavy burden on the water quality of the rivers and streams in the many watersheds around the state. All of which feed into the Missouri and Mississippi Rivers bounding our west and east coastlines.

The University of Iowa Institute of Hydraulic Research in Hydroscience & Engineering (IIHR) helps understand the demands on the water flow throughout the state. It helps engineer solutions to the problems encountered in keeping our waters safe. Water quality engineer Chris Jones recently examined the nitrogen (N), phosphorus (P), and total solid matter (TS) of the animal wastes and compared them to equivalent human N, P, and TS levels. His results were published in his blog and were astounding. Please read his post for the details.

The impact of all those animals raised in Iowa was equivalent to a human population of 134 million people. That ranks our state as the 10th most populous ‘nation’ compared to humans alone, behind Russia and ahead of Mexico. To make his point, he put various equivalent human population centers of the world within the watershed boundaries. It is no wonder our rivers and streams are suffering from critical levels of runoff.

Chris Jones | Water Resources Engineer | IIHR

Chris Jones was not trying to pass judgement upon the livestock industry. It is a mainstay in our economy. He says it is important for leaders in the state to examine environmental outcomes along with the economic and regulatory considerations of the industry. I agree.

13 thoughts on “Iowa’s Huge Population Problem

  1. That the animal population of Iowa is equivalent to a human population of 134 million is indeed remarkable. I’m sure that calculations of other agricultural states like Nebraska, Texas and Arkansas would yield similar numbers. Humans are consuming and changing the Earth at an unsustainable rate. Rather than sending astronauts to Mars we should be adapting spaceship Earth to a sustainable course. Thanks for an eye-opening post, Jim.

    • Yes, the numbers grow to staggering amounts. We are having continuous problems with nitrates in the rivers and water supplies.

      Thanks for your visit.

  2. I agree too. Changing the ways we do things is always a difficult thing, with people feeling threatened. I’ve read of a cattle ranch in California where the beef is grass-fed. They move the cattle from pasture to pasture to maintain the health of the land and the stream that runs through it, and are doing such a good job that a rare salamander thrives on their ranch. So it can be done, growing our food and allowing nature to thrive alongside. I’ve also read that it would be very good if more people raised their own food, thus decentralizing animal and crop production and relieving some pressure on our water supply. In theory I’m on board with that but if I or a neighbor had roosters, or pigs, I’m not sure I’d be happy.

    • You raised some excellent points. Considering that we waste massive amounts of food through the industries, more efficiency and smaller scales might be better. No doubt there are arguments to be made on both sides. But, we need to have that discussion.

      I’d rather not have pigs and chickens next door, either.

      • We have a community garden in our town, over by the library and a bit away from houses. I wonder if a small flock there would work….
        I hadn’t even thought about all the wasted food. Ugh. You’re right. Yesterday I saw a small truck in the neighborhood with “Ugly Produce” painted on the side. I surmised they were delivering produce that wasn’t pretty enough to be in the grocery store and was cheered. In fact, I’ll have to google them and see what they are about.

    • I was very surprised when I read the post by Jones. The impact of all those animals was not something I’d considered in that way. And, I have lived in the rural heartland my whole life. It has opened my eyes.

  3. It’s certainly an issue that’s taken seriously here in Texas. There are areas, especially farther north in the Panhandle, where enormous numbers of feeder cattle are raised. There are some turkey production facilities (seasonal, for the most part) and also chickens, but it seems as though there’s at least awareness of the problems that can arise because of such concentrations of animals.

    Of course, many herds in Texas roam huge ranches, which presents other challenges. But there’s also a movement toward smaller scale meat production. Pastured pork and beef are available in many places now; both can be purchased at the farmers’ markets here in Houston. Not only does wise pasturing reduce some of the problems associated with large herds, the meat’s much tastier.

    • Good that the issue is taken seriously. We don’t have the large ranches to allow herds to roam. Instead we have concentrated lots, pens, and buildings for the various livestock.

      The farmers’ markets have more offerings of grass-fed animals, eggs, cheese, etc. I agree, they are helpful and better tasting.

  4. Very interesting post. I am not sure what the answer is. Actually I do, I just don’t like it

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