Iowa making a drought plan as climate risks increase

CEDAR RAPIDS — As nights stay hotter and precipitation is less consistent, Iowa is at risk for more frequent droughts.

That’s why state officials want to develop a plan that would include a trigger point to call for precautions, such as water rationing.

“The benefit of a trigger is it gives you something to point to,” said Tim Hall, chief of the Iowa Geological & Water Survey Bureau at the Iowa Department of Natural Resources.

About 20 emergency management officials, water treatment employees and others gathered Thursday at Kirkwood Community College in Cedar Rapids to talk about the need for a drought plan and what should go into it.

This is one of five stakeholder meetings across the state.

The nonprofit Climate Central group of scientists and communicators reported Iowa, Montana and Oklahoma have the worst drought vulnerability among all 50 states based on exposure and sensitivity to drought as well as their ability to adapt to it, State Climatologist Justin Glisan said Thursday.

“We don’t irrigate across the state or have the ability to irrigate,” Glisan said of Iowa’s agricultural crops, primarily corn and soybeans. “Our crops need water. Corn needs 25 inches of water per year to grow.”

Glisan and other state officials hope that by creating a drought plan, Iowa can reduce its vulnerability. The long-term climate trends are concerning, Glisan said.

Iowa’s average daily temperature has increased about 1.3 degrees since 1895. That doesn’t sound like a lot, but the bulk of that change is happening at night, when cloud cover traps the heat from the day close to the Earth.

“Not cooling off at night exacerbates drought conditions,” Glisan said.

A warmer atmosphere holds more water vapor — about 4 percent more in Iowa — and doesn’t let it go as rain until it reaches critical mass.

This means some of Iowa is more likely to get 3 to 4 inches of rain in a few hours, leaving parts of the state very wet while others still are experiencing drought, Glisan said.

Much of Iowa faced drought last summer. Despite a wet October, when an average 5 inches of rain fell across the state, much of Iowa still is dry.

The U.S. Drought Monitor’s most recent Iowa map, published online Thursday, shows extreme drought extending into a third northwest Iowa county, as compared with the previous week, and southeast Iowa developing a pocket of moderate drought.

Participants at Thursday’s meeting said the drought plan should factor in rainfall — both here and in the watershed farther north — temperature and soil moisture. They said having a state plan that defines drought will make it easier to impose water restrictions if necessary.

Hall said one idea is to create a drought website, similar to the Iowa Flood Information System, that could gather data on drought risks and model how that would affect different parts of the state.

The Iowa DNR, Iowa Homeland Security and Emergency Management and the Iowa Department of Agriculture and Land Stewardship plan to create by October a draft plan that will be available for public comment. They hope to have the final plan by the end of the year.

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