People and property along the Cedar and Iowa rivers are nearly as vulnerable to a big flood now as they were in June of 2008, experts say.
“We have hardened and flood-proofed a lot of buildings in the flood plain, but given rainfall like we had in the spring of 2008, the water is still going to rise to the same level,” said Larry Weber, director of IIHR — Hydroscience & Engineering, the parent organization of the Iowa Flood Center.
Weber said the Iowa Flood Center, a research unit founded in response to the 2008 floods, has developed computer models that can identify the most cost-effective practices for reducing the peaks of future floods.
“We still have a long way to go in implementing those practices,” he said.
“We are maybe 10 percent of the way there,” said Sen. Rob Hogg, D-Cedar Rapids, who helped establish both the flood center and watershed management authorities, which bring together cities, counties and conservation agencies to formulate a coordinated, watershed-level response to flood risk.
The flood center is working with watershed management authorities on the Upper Cedar and Turkey rivers to implement some water retention projects that will document and underscore their value in reducing peak river flows.
Hogg said Cedar Rapids has greatly reduced its vulnerability by buying out more than 1,300 flood-prone properties and relocating key city infrastructure such as the library and fire station beyond the reach of a 2008-level flood.
Both Cedar Rapids and Iowa City escaped major damage this month when predicted late-May storms failed to materialize, he said.
“Now we have to be more proactive. We need flood protection systems and comprehensive watershed management to absorb and slow the runoff of excess water,” Hogg said.
“We need to give the flood plain back to the river,” said Vern Fish, director of the Black Hawk County Conservation Department and co-chairman, along with Hogg, of the Cedar River Watershed Coalition, which was founded in 2010 to foster cooperation within the watershed and urge adoption of policies to reduce future flood damage while improving water quality.
Mary Beth Stevenson, Iowa and Cedar basin coordinator for the Department of Natural Resources, said she is encouraged by the partnerships established across city and county boundaries and the adoption of a watershed approach to flood control.
Although more than 4,000 acres of water-absorbent land has been established since 2008 in the 23-county watershed of the Cedar River, “we are losing absorption faster than we can acquire it,” Fish said.
“If anything, we are more vulnerable than we were in 2008,” said Rich Patterson, director of the Indian Creek Nature Center in Cedar Rapids.
“Instead of establishing more water-absorbing perennial vegetation in the flood plain, we are creating more pavement, more roofs and we have invested a tremendous amount of money in areas that flooded in 2008,” Patterson said.
In the five years since the record flooding, high corn and soybean prices and highly subsidized federal crop insurance have actually encouraged the conversion of perennial vegetation, which slows runoff, to row crops, which do not.
“It’s our federal farm and energy policies telling farmers we want more corn and beans,” said Bill Ehm, administrator of the Department of Natural Resources’ Environmental Protection Division.
In the 27 counties at least partially drained by the Iowa and Cedar rivers, 40,005 acres of Conservation Reserve Program grassland — the equivalent of 63 square miles — has left the program since 2008, said Todd Bogenschutz, the DNR upland game biologist.
Although data on the conversion of hay and small grains to corn and soybeans is less precise, Bogenschutz said “acres in those perennial crops have also declined.”
Hogg said comprehensive watershed management is a good investment.“Spending $100 million to improve water retention could save $1 billion in damage during the next big flood, and you get the additional benefits of improved water quality and much needed wildlife habitat,” he said.