Cedar Rapids, Readier for this Flood

How Sasaki’s run-ins with Iowa floods helped Cedar Rapids weather the storms to come.

By Zach Mortice 

The 2008 flooding in eastern Iowa saw the Cedar River crest at 31 feet, inundating much of downtown Cedar Rapids. Image courtesy of Sasaki.

On the morning of Jun 12, 2008, the landscape architects Gina Ford, ASLA, and Jason Hellendrung, ASLA, of Sasaki woke up in their hotel rooms by the riverside in downtown Cedar Rapids, Iowa, to stifling heat and eerie silence. They were in town to pitch their riverfront master plan to the city council. They knew the Cedar River was expected to flood (and had stocked up on water, granola bars, and bananas just in case) but neither expected any sort of ordeal stemming from the river, which they had come hoping to reimagine as a lively and gregarious urban greenway. The power, air-conditioning, and phones were out. The hallways were empty and pitch black, and a ferocious rainstorm had darkened the skies and pushed the encroaching floodwaters. Reaching each other via cell phone, they discussed their options. In the distance, the Quaker Oats cereal mill plant’s red neon sign was still lit. “It can’t be that bad,” said Hellendrung. “They still have electricity.”

“As I said that, there was a bolt of thunder and lightning, and the sign went out. Then I was like, ‘Maybe the police will get here soon?’”

Police did dispatch rescuers, who led Ford and Hellendrung out of the hotel. A second-floor connection to the convention center saved them from having to make a wet exit from the city.

“It was something that we lived very directly,” Ford says. The subsequent years saw Ford and Hellendrung dig into a much broader and more ambitious flood mitigation plan for Cedar Rapids. Now the city recently has had another major flood, which it weathered better, in part, because of the disaster planning Sasaki provided.

Sasaki’s plan called for a 220-acre greenway filled with parks and recreation spaces to act as a flooding buffer along the river. Image courtesy of Sasaki.

The 2008 natural disaster in eastern Iowa was an epochal 500-year flood. The Cedar River, which bisects the small Iowa city, crested over its banks by 31 feet, putting 10 square miles of the city (including its downtown) underwater, according to the Cedar Rapids Gazette. Twenty-four thousand people were evacuated, and 7,000 properties were affected, causing $6 billion in damage. FEMA picked up $848 million of the bill, its sixth-largest disaster declaration ever.

Sasaki had grown familiar with the Cedar River’s role in the city. The flood opened a wider exploration of ways to leverage disaster resilience into a cultural and civic plan for the city. The plan, called the Cedar Rapids River Corridor Redevelopment Plan, worked first on ways for the city and river to coexist better, then pushed on ways to encourage growth and stop the city’s loss of younger people to other cities.

An amphitheater along the river doubles as a flooding levee. Image courtesy of George Burrows.

The plan’s first phase calls for a new system of levees, pump stations, park spaces, and detention basins, much of it financed by a sales tax-driven tax increment financing district that will provide $264 million over 20 years. Part of this system is a gently sloping levee that doubles as a riverside amphitheater, completed in 2013. Phase two of the plan considers transit connections, walkability, landmark preservation, and, especially, housing. It focuses on replacing flooded housing units with denser units at market and subsidized rates.

But the toughest and most progressive part of Sasaki’s plan asked how much of the city should be given back to the water permanently. Sasaki showed an option for building everything back the way it had been, this time with higher and higher floodwalls, which would have walled the river off from the rest of the city, separating it from “the one thing that’s a unique defining characteristic of your community,” Hellendrung says. Alternatively, Cedar Rapids could have backed away from any parcel that flooded. That was Sasaki’s recommendation for Mays Island, the narrow sliver of land in the middle of the Cedar River that held its city hall until after the 2008 flood, and still contains the county jail and courthouse, both of which were evacuated in 2008 and 2016. Mays Island is still home to the Beaux-Arts Veterans Memorial Building—as close to iconic as the Cedar Rapids skyline comes—reinforced against flooding after an $18.5 million renovation, according to the Cedar Rapids Gazette. But the plan the city chose was a middle path between these two options. It committed to rebuilding some parcels. But it still voluntarily ceded large portions of the downtown business district and close-in neighborhoods back to the river. When Sasaki’s plan is completed, a 220-acre greenway (assembled from approximately 1,300 properties the city acquired) filled with park and recreation spaces will line the river, ready to absorb floodwaters.

Temporary flood barriers are installed across the Cedar River from Mays Island. Image courtesy of the City of Cedar Rapids.

Adam Lindenlaub, a Cedar Rapids city planner, says the public and their elected leaders understood that giving the river some of the floodplain back was the most sustainable option. They knew that “there is going to be a threat of flooding, and we can’t really prevent that,” he says. “Our city councils really stuck with [the plan].”

“They had very strong principles about making sure whatever we did left the city stronger and better positioned following this disaster, and also that it be a very engaged community conversation,” Ford says. “There was more public outreach in the wake of the flood than we’ve ever been a part of, before or since.”

Sasaki’s plan received an APA National Planning Excellence Award, an example of a city actually bringing flood resilience plans to fruition. Cedar Rapids is “the premier example of a community that’s gone through a disaster and built back in a resilient way,” Hellendrung says.

The temporary sand-filled HESCO flood barriers use a metal mesh with an impermeable liner to block floodwaters, and were laid out in accordance with Sasaki’s plan. Image courtesy of the City of Cedar Rapids.

Lindenlaub says, “Flood recovery is a marathon. It’s not a sprint.” Full execution of Sasaki’s plan could take 15 years. But catastrophic floods won’t wait that long. The 2016 flood last month was less severe, but still saw the Cedar River crest at 22 feet, its second-highest level ever, prompting calls for 6,000 residents to evacuate. In an interim flood plan, the city set up 10 miles of temporary sand-filled HESCO flood barriers made of metal mesh and an impermeable liner along the river. For this year’s flood, Sasaki’s in-depth plan guided placement of the barriers in spots where permanent levees had not yet been built, weaving into new features like the levee amphitheater. “[It’s] not necessarily that we had everything built, but we know where the alignment was [and] we knew where to put things,” Lindenlaub says. With the interim plan, the city largely avoided surface flooding from river water overrunning its banks.

The Sasaki plan moves beyond basic disaster resilience to consider broader issues of transit connections, walkability, landmark preservation, and housing. Image courtesy of Sasaki.

But even with Sasaki’s plan, addressing the macro-level ecological issues causing this flooding will be much harder. The underlying factors here are deeply embedded in Iowa’s economy, and far upstream from where the flooding happens, literally and metaphorically. Cedar Rapids sits at the bottom of its watershed, and more than a century of turning prairie grass into cropland for industrialized agriculture has robbed the land of its ability to capture and contain rainwater like a sponge. Combine this with increases in severe weather driven by climate change, and you have a recipe for what were 100-year floods popping up twice a decade, as with 2008 and 2016.

“No city really has all of the tools to deal with a disaster of this scale,” Ford says. “The cities at the bottom of the watershed can’t solve all of the contributing factors that lead to these things. The thing that’s so frustrating is that when you’re talking about disasters and natural systems of this scale, the boundary of the problem that you’re given is not nearly enough to address the problem. That’s a profound lesson cities have to deal with.”

Zach Mortice is a Chicago-based architecture and landscape architecture journalist. You can follow him on Twitter and Instagram

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