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.

River Cleanup | Sustainable | Natural

Sometimes a solution to a problem comes along that is simple and elegant and deserves to be promoted. This is one of those situations. The Inner Harbor of Baltimore, MD, is fed by the Jones Falls river watershed to the north. People carelessly leave trash on the ground and in the streets instead of in proper receptacles. When it rains, this trash is washed into the river and then into the Inner Harbor. It is ugly and unhealthy. Clean-up has been an ongoing chore for the city.

Since May 2014, the job of trash removal from the river has been made much easier with the use of a current-driven and solar-powered water wheel. Current flows from right to left. This perspective view shows two floating orange booms which guide the trash into the device. The device brings the trash up a conveyor and dumps it into a dumpster. If you are interested is seeing a screenshot of the 2014 trash totals by category, monthly precipitation, tonnage and volume, follow this link. The wheel continues to operate during the winter months.


Ziger/Snead | Baltimore | River current flow is right-to-left

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