Wednesday, November 16, 2022

University of Iowa PhD student Riley Post hopes his research changes the way we fight floods.

Post was named the winner of this year’s Three Minute Thesis competition (3MT), a universitywide contest that tasks graduate students with relating their research in three minutes or less to a general audience.

Post’s research, which uses a technique called distributed storage, focuses on using a network of rivers, ponds, and reservoirs with monitored, gated outlets to control the flow of water. From a central location, one could control when, how much, and where water flows. By controlling these waterways as one giant network, the system could reduce flooding.

Post compared this system to roads, parking lots, and stoplights.

“Let’s think about rivers as roads that move water and reservoirs as parking lots that we use to store water,” Post said during his 3MT presentation Nov. 4. “These gated outlets can serve as stoplights.”


Humans have been fighting floods the same way for hundreds of years—by filling sandbags and piling dirt. As extreme rainfall becomes more common and more people build houses in flood plains, Post says he thinks the time for changing the way floods are managed is overdue.

“One hundred years ago, they didn’t have these tools, and so computers allow us to be more precise than humans ever could,” Post says. “We are trying to figure out how to allow our flood fighting to catch up with our technology. We can operate our model and say, open up the gate 30% or 42%, and let the water out. We know the size of the pipe, how much water can come out and what is stored in the dam, so we know exactly how that will impact surrounding areas.”

Post’s research yielded a concept that uses a series of ponds that feed to a creek or river. The gates to the ponds would open or close based on the flood risk of the area. In his simulation, during a flood risk Post can put on a red light to close the gates, allowing for these reservoirs to accumulate excess rain.

When floods have passed, Post can put on a green light, and water retained would flow back into the creek or river at a controllable rate that doesn’t overwhelm the waterways.

Post is using simulated data from the Soap Creek Watershed, a 130-pond network, which branches off from the Des Moines River in southeast Iowa. Post says he is confident that if expanded upon to thousands of bodies of water across the state, his concept will show meaningful reductions in flooding.

“My hope is that a community will say we can invest X-amount of dollars and get these drastic decreases in flooding,” Post says. “I’m guessing it would catch on fairly quickly.”

Post is not new to this field or to fighting floods. He spent 10 years working as a water resources engineer for the U.S. Army Corps of Engineers in the Rock Island, Illinois, district after completing an undergraduate and master’s degree at Iowa in 2010 and 2011, respectively.

He worked in water control, operating locks and dams and flood control reservoirs like the Coralville Reservoir. He returned to Iowa to begin the PhD program in civil engineering in fall 2020.

Post’s first interest in flooding stems from his memories of growing up a mile away from the Mississippi River outside of Blue Grass, Iowa.

“The river is maybe a mile away from my parents’ house,” Post says. “One of my first memories was during the flood of 1993. My dad worked in Davenport, and I remember dropping him off at a canoe so he could get to work. I remember thinking how weird it was that the road was underwater.”

Post learned to sandbag during a flood in 2001 and was an undergraduate at Iowa during the 2008 flood that caused extensive damage to campus.

The next step in Post’s research is to move from a reactive approach to a proactive approach using forecasts.

“My question is, can I operate a system of dams using rainfall forecasts?” Post says. “So, before the rain even falls, can I start draining these ponds in anticipation of rain, making room for storage?”

Post is the third-straight civil and environmental engineering student to win the 3MT competition. He credits his program for emphasizing the importance of communication.

“In the civil engineering program, we are required to take four semesters of what's called the coaching seminar,” Post says. “It’s all about presentations, presenting your work in lots of different ways, and they really encourage you to do the 3MT.”

Post plans to graduate in spring 2024 and hopes to become a faculty member at a college or university.

“I love doing research and I love teaching,” Post says. “The teaching bug is what got me to leave my previous job and return to school. When you’re enthusiastic about something, you want to share it with people.”