Iowa has little idea of the cost to fully protect it from flooding

Iowa is seeing heavier rains and more flooding as climate change takes its toll, yet the state has little idea how much it would cost to protect its homes, schools, factories and other infrastructure, let alone how to pay for it.

Iowa cities and towns have put together $1.4 billion in plans to protect themselves from flooding, seeking to buy homes and businesses near rivers, build levees and flood walls and better protect utilities.

But the state has failed to aggressively push to build wetlands, detention ponds and other upstream structures that can significantly reduce flooding risks for cities and towns.

Sen. Rob Hogg, D-Cedar Rapids, said some Iowa lawmakers have discussed the need for increased flood mitigation that could also reduce nitrogen and phosphorus runoff. But that message has gotten lost amid intense budget fights over education, health care and other funding needs.

"If you can't reach agreement over funding the basics, it's really hard to get to the next level, to discuss funding water management," Hogg said.

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Iowa researchers are assessing the impact of upstream flood mitigation efforts — as well as determine the costs, said Larry Weber, director at the University of IIHR - Hydroscience & Engineering.

Weber estimates the price tag to better protect the state against more frequent and intense flooding at $4 billion to $5 billion, double the amount Iowa expects it will need to pay to improve water quality.

Indeed, work to cut flooding has taken a back seat as the state focuses on finding funding for water quality in the wake of a pending lawsuit that Des Moines Water Works filed against three north Iowa drainage districts over high nitrate levels.

The state also is under pressure to cut the nutrient losses that contribute to the dead zone in the Gulf of Mexico, an area about the size of Connecticut that's unable to support aquatic life each summer.

Lora Friest, who leads a northeast Iowa watershed management group, says families, farmers and communities upstream from Cedar Rapids, Iowa City and other flooding cities want to help reduce the amount of water that's expected to swallow Iowa homes and businesses with increasing frequency.

In the Turkey River watershed, where Friest works, farmers allow their fields to flood and provide land for ponds and water detention, while county crews design roads that can double as flood-retention walls.

Friest's group has built nine water-retention projects to reduce flooding, thanks to a federal grant state officials landed following the massive 2008 flood.

The group has more plans, Friest said. "All we need is funding."

More frequent flooding

One reason flood mitigation needs greater attention is that extreme rainfalls are likely to happen more frequently, thanks to climate change and, to a lesser degree, land-use changes, experts say.

"We were hard-pressed to get 4-inch rainfalls 100 years ago, and now it's very common," said Jerry Schnoor, co-director at the University of Iowa's Center for Global and Regional Environmental Research.

Through Sept. 30, rainfall across Iowa averaged nearly 45 inches, 9.6 inches more than normal. That makes this the state's third-wettest water year since the state started keeping records 144 years ago, according to the Iowa Department of Natural Resources.

Torrential rainfall in September resulted in a record crest along the Shell Rock River, as well as the second-highest crest on record along the Cedar River.

The Cedar's record crest in 2008 led to $5 billion in flood damages.

"In the Cedar River basin, we found the 100-year flood a century ago is now very likely to be a 25-year flood," said Eugene Takle, director of the climate science program at Iowa State University.

The term “100-year flood” is used to describe a flood that has a 1 percent chance of occurring in a given year. A "25-year-flood" has a 4 percent chance of occurring in a year.

Takle said accumulating greenhouse gases are warming the atmosphere, enabling it to hold more water vapor. "When you have more water vapor, you can expect more rain events," he said.

Takle's data illustrate the shift:

• Statewide annual average rainfall in the winter has spiked 33 percent since 1970, while spring rainfall has climbed 11 percent and summer rainfall has risen 18 percent. Meanwhile, fall rainfall has fallen 14 percent.
• Atmospheric water vapor, or humidity, has increased 31 percent in the winter since 1970, 14 percent in the spring, and 13 percent in the summer.

"A change in seasonality is kind of a big thing," Takle said. "Precipitation isn't just going up and down uniformly over all seasons. We're seeing more in one season and less in others.

"It may not be enough of a shift to impact agriculture … but the increased rain we're getting in the planting season is creating headaches," he said.

In Des Moines, the number of years that have had more than eight erosion-producing daily rains has climbed 400 percent over 120 years, comparing the first six decades to the last six decades, Takle said.

"This is consistent with what the climate models said would happen," he said. The Midwest "has experienced a big increase in extreme events."

A federal report in 2014 showed the average Midwest air temperature increasing 1.5 degrees Fahrenheit between 1900 and 2010.

Since 1980, Iowa has had 26 flood disasters with damages exceeding $1 billion, according to NOAA National Centers for Environmental Information. All told, Iowa has had 41 extreme weather events, including droughts, tornadoes and other disasters.

Schnoor said land use also contributes to flooding. Urban development, replacing soil with concrete and steel, can drive water faster into streams and rivers.

But it plays less of a role in Iowa, where about 80 percent of Iowa's 36 million acres are used for farming, Schnoor said. Much of the state’s 30 million farm acres are drained by underground tiles.

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Weber acknowledges the loss of Iowa's wetlands and prairie potholes — shallow wetlands that "acted as a sponge" and soaked up heavy rainfalls — have hurt the state's ability to absorb heavy rains, as has the loss of perennial grasses and crops that helped absorb rainfall year-round.

"We've taken away a lot of those natural storage areas," he said.

But nature can handle only so much water, he said. "Think about the capacity of soil to accommodate in excess of 2 inches of rain. It will directly run from the land, regardless of whether there’s tile" underneath.

Takle said Iowa flooding is shifting from early spring, with upstream snow melts filling rivers and streams, to late spring and summer.

"We didn't get these summer floods back in the first half of the 20th century. At least not as frequently," he said. "That's climate change. … That's the atmosphere holding more moisture, as we know it is."

"We've turned up the heat on the Gulf of Mexico … which puts more water vapor in the atmosphere, and that's being transported northward," he said, pointing to flooding in Louisiana this year.

"We know we have more water vapor to fuel these storms," Takle said. "It's all a consistent picture, and it's very likely to continue."

Investing in flood control

In 2012, Iowa lawmakers approved a sales-tax funding plan that's helped 10 mostly large cities with about $1.4 billion in flood projects.

Once the projects are completed over the next two decades, the state expects they will help avoid $6 billion in damages.

The state plans to provide nearly $600 million to communities for improvements by allowing them to retain part of the projected increase in state sales taxes. Local governments are expected to provide about $361 million; and the federal government, $426 million, state documents show.

However, Iowa cities may never get the full funding they hope to see from the federal government, experts say, because of intense competition for financing. That's slowed development of levees expected to protect cities and towns across the state.

Hogg said the state also never funded a grant program that was designed to help small communities unlikely to see any increase in local sales tax receipts.

Eighty-nine towns and cities have identified at least $35 million in flood mitigation improvements that lack funding.

MORE: Full coverage of 2016 flooding in Iowa

John Benson, a spokesman for Iowa Homeland Security and Emergency Management, said the agency suspects the needs are much greater, and they'll likely see requests for more projects as federal funding for the latest flood becomes available.

Already, Benson said the flood improvements made so far have enabled the state to avoid $91 million in damages, in part by buying about 1,400 flood-prone homes in Cedar Rapids.

It's unclear so far how much damage the September flooding caused as storms raged through 25 counties in north central and northeast Iowa.

Initial assessments of nearly 500 homes and businesses in 10 counties show about 90 have received major damage and 10 are considered complete losses. About 390 buildings have received some flooding or minor damage.

Road, bridges, parks and other infrastructure damage in 18 counties so far sits around $25 million, Benson said.

Finding more money

Hogg, the state lawmaker and a Cedar Rapids attorney, wants to increase the amount of sales tax that Iowa cities and towns can access for flood improvements, and fund the grant program for small communities. Lawmakers had hoped to make $4 million available annually to small communities.

He'd also like to increase the income limits so more flood victims can access up to $5,000 in grants for home or car repairs, to replace lost clothing or pay for temporary housing.

He supports adding three-eighths of 1 cent to the state sales tax to fund the Natural Resources and Outdoor Recreation Trust Fund. In 2010, 63 percent of Iowa voters approved a constitutional amendment to create the fund, but the Legislature has failed to provide funding for the initiative.

A sales tax increase would provide $180 million annually to restore wetlands, protect wildlife habitat, reduce runoff and improve trails, among other initiatives.

Friest, executive director of Northeast Iowa Resource and Conservation Development, hopes that cities and towns consider long-term upstream solutions when they look at flood mitigation spending.

"If a city is willing to spend $4 million on sandbags every time it floods, maybe they could spend $4 million above them" to reduce flooding's impact, Friest said.

She said many rural counties struggle to repair road and bridge damage, let alone tackle flood improvement projects.

"Some of these rural counties are the poorest in the state," she said.

"Are you going to look at them and say, 'You have pay for these structures to protect our communities?'" Friest said. "They can't, even if they want to. And they do want to help."

Promising developments

Weber said models show that $1.5 million in improvements made each in three watersheds — the Otter, Beaver and South Chequest and Soap creeks — would reduce downstream flooding 15-20 percent.

The money for the watershed project was part of federal supplemental disaster aid the Iowa Flood Center received after the 2008 flood.

This year, the state received a $98 million federal grant for flood mitigation. Part of that money will go to develop similar projects in up to 25 watersheds, Weber said.

Large chunks of money also will go to Dubuque, Coralville and Storm Lake.

"We’re making great strides in the places where we work," Weber said. "We just need to be working in more places — whether it's through our projects, or the work of other state and federal agencies, private landowners, and nonprofit groups."

Weber said the Iowa Flood Center expects to create a more comprehensive cost-benefit assessment of upstream flood mitigation.

"Iowa has been impacted by some type of flood each and every year since 2008 in some part of the state … and it's raising the expectation that something does need to be done," Weber said.

"Now, getting it done, getting it in place and getting the funding lined up, that’s a more complex question."