Andy Davis

aldavis@press-citizen.com

How much has Iowa City grown over the last 177 years?

An interactive online map posted this week illustrates just how much in about 90 seconds.

The map, posted this month, was developed by Mark Pooley, a research associate and geographic analyst at the University of Iowa Public Policy Center. Pooley compiled data on the year buildings were erected from the Johnson County and Iowa City assessors' offices and, through open-source software, created an animated timeline of where buildings sprang up in Iowa City, Coralville and University Heights from the mid-1800s to 2014.

"I was going through my hard drive one day trying to clean up some junk data, and I had some of this sitting around from another project that had been lingering, and I thought, 'Well, it's kind of interesting to visualize stuff,' " Pooley said. "I do spacial analysis, (geographic information system) work, mapping, data crunching and anything that falls under that umbrella.

"I'm also a sucker for maps, and Iowa City is where I hang my hat, so I thought it would be cool to do something like this," he said.

At first, Pooley said he intended to map all of Johnson County, but the file size became too cumbersome and there were difficulties loading the interactive features.

Pooley's map has garnered the attention of city staff and local historians. Josh Moe, vice president of Friends of Historic Preservation, noticed the map and reached out to Pooley, pointing out some inaccuracies in some of the building dates in downtown Iowa City.

"This is an awesome tool, and Mark has done some great work. But when I was looking at it I noticed that the downtown area wasn't very accurate," Moe said. "The entire block bound by Clinton Street, Iowa Avenue, Dubuque Street and Washington Street all says they were 1900 construction projects, which I know to be inaccurate."

According to Pooley's map, there was a huge construction spike at the turn of the 20th century.

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County Assessor Tom Van Buer said assessors' offices in the state weren't established until the 1940s, and 1900 served as a general estimate for houses that predated the 1930s. That fact could account for the spike, he said.

"In looking at a house's foundation, for example, if you have a limestone foundation on an old house it's going to predate the 1930s, so when we were doing things like that in the '60s, '70s and '80s, if we knew it was older than 1930 we just estimated it as 1900," Van Buer said.

Pooley said on Monday he will meet with Kris Ackerson, a community development planner, to talk about how similar coding could be used to map affordable housing and the rental market in Iowa City.

"Affordable housing is one of our core missions in the neighborhood services division, and we deal with affordable housing providers and look at ways to improve affordability," Ackerson said. "I'm sort of in brainstorming mode right now, so it's kind of too early to say what might come out of this. But it's a neat tool and a great way to present data."

As a presentation tool, Pooley said the map is a useful way to break down the data into a consumable format, adding that he'd be happy to work with local historians and city staff on improving the map and putting the coding to other uses.

See the map

Visit http://markpooley.github.io/yearbuiltjc/ to view Mark Pooley's interactive map of when structures were built in Iowa City.

Reach Andy Davis at 319-887-5404 or at aldavis@press-citizen.com, and follow him on Twitter as @BylineAndyDavis.



