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Data suggests Iowa really is getting wetter
Orlan Love
Aug. 29, 2010 12:03 pm
Muddy rivers, moldy classrooms, swarming mosquitoes, blighted tomatoes and effulgent quack grass will be mere annoyances in Iowa's new era of serial cloudbursts.
Unless Iowans adjust dramatically to more extreme precipitation and flooding, they can expect more swamped crops, failed dams, submerged cities and monolithic public institutions turned into indoor swimming pools, said Gov.
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Chet Culver, who recently dubbed the chronically wet conditions plaguing Iowa as 'the new normal.' It's an assessment shared by other public officials and Iowa climate scientists.
'It's just something we are going to have to deal with, and we'd better adjust in all ways that we can,' Culver said earlier this month, following the Maquoketa River dam failure that drained Lake Delhi.
'We need to face reality,' said Kamyar Enshayan, director of the Center for Energy and Environmental Education at the University of Northern Iowa and a member of the Cedar Falls City Council.
'There is significant, solid evidence that Iowa is experiencing a new normal in precipitation and flooding.' Cedar Rapids Mayor Ron Corbett, who is leading an effort to secure funding for flood-wall protection on both sides of the Cedar River, said he believes the research and evidence support increased precipitation causing more frequent and severe flooding.
'My worst fear,' he said, 'is the kind of heavy, prolonged downpours that we have experienced in recent summers happening in the spring when the rivers are already full of snowmelt.' Iowa City Mayor Matt Hayek, operating under a 'when, not if' assumption, said the city 'is devoting significant resources to the protection of public and private property and the mitigation of future events.' While Enshayan and other scientists attribute the recent extreme rainfall in Iowa, Pakistan and other places to global climate change caused by human carbon emissions, one need not ascribe causes to recognize that Iowa's climate is rapidly getting wetter - in terms of average annual precipitation and the frequency of downpours, said Iowa State University professor Eugene Takle, one of the state's leading climate scientists.
The past three years have been the wettest 36month period in the 138 years that Iowa has been keeping records, said State Climatologist Harry Hillaker.
From August 2007 through July 2010, Iowa recorded a statewide average of 134.72 inches of precipitation, beating the old record of 124.8 inches established from October 1990 through September 1993, Hillaker said.
In 2007, Iowa recorded 43.85 inches, making it the state's fifth-wettest year; 2008, with 43.79 inches, was the fourth wettest; 2009, with 40.05 inches, was the 11th wettest; and this year, with 34.66 inches through Aug. 18, is on track to become the second-wettest year, Hillaker said.
To put those 40-inchesplus years in context, consider that Iowa has had just 11 of them in 138 years and that the longterm statewide average over the past 138 years has been 32.44 inches.
From 1875 to 1950, Iowa recorded only two years with more than 40 inches of precipitation. Since 1950, the state has recorded eight such years, and this year likely will be the ninth, Takle said.
And when it rains, it pours. Since 1910, days with more than 4 inches of precipitation have increased 50 percent in the Upper Midwest, said Christopher Anderson, assistant director of Iowa State University's Climate Science Initiative.
During the late 1800s, Cedar Rapids averaged 4.2 days a year with precipitation of 1.25 inches or more - the amount at which runoff to streams typically becomes significant. By 2008, that figure had risen to 6.6 days per year, a 57 percent increase, Anderson said.
Expressing that same trend another way, Anderson said that between 1895 and 1947, Cedar Rapids had two years in which 1.25 inches or more of precipitation fell on nine or more days. Since 1947, Cedar Rapids has recorded 11 such years, he said.
Takle said all that data does not constitute ironclad proof that Iowa has entered a substantially wetter era, but it would no longer be prudent to consider 20th-century precipitation averages as a baseline for planning.
Corbett said this summer's floods have kept the issue of flood protection front and center.
State Sen. Rob Hogg, D-Cedar Rapids, said the floods have elevated flood protection to a level comparable to fire and police protection in the lives of most Iowans and that they have made state flood policy a paramount issue in the Nov. 2 elections.
Culver and his Republican opponent, former Gov. Terry Branstad, could hardly be farther apart on the issue.
'We have to recognize that weather patterns go through cycles. We are in a wetter cycle right now, but these things change.
You have to deal with it as it comes,' said Branstad, who vividly recalls steering the state through its last major drought in 1988 and 1989.
Branstad said state leaders need to formulate uniform, consistent policies to deal with whatever disasters the state may face.
'It doesn't make sense to do it with borrowed money,' as Culver has done with his I-JOBS program, Branstad said.
Branstad has frequently criticized Culver's $875 million public infrastructure program, while Culver notes that $300 million of it has been allocated for flood recovery and mitigation projects.
'We've not invested enough in flood prevention and mitigation. It needs to go higher up on the list,' Culver said.
Enshayan compares the June floods of 2008 with the Sept. 11, 2001, attacks on the World Trade Center and the Pentagon in the sense that both exposed huge vulnerabilities and the need to adopt protective measures.
'We have to act. There is no way around it,' Enshayan said.
Enshayan prescribes three actions to increase Iowans' flood security.
'We need to quit building in flood-prone areas.
We need to invest heavily in renewable energy and energy conservation.
And, most important, we need to restore the hydrologic functions of our river basins by making our watersheds more absorbent,' he said.
State Sen. Hogg has been urging Iowans since the 2008 floods to improve flood plain and watershed management to minimize future peak flooding and flood damage.
By replacing native tallgrass prairie and wetlands with row crops, Iowans have largely destroyed one of the earth's key 'ecosystem services' - moderating the flow of water over and through the land, said ecologist Cornelia Mutel of rural Iowa City.
Mutel edited 'A Watershed Year: Anatomy of the Iowa Floods of 2008,' the most thorough analysis to date of the state's largest natural disaster.
To help moderate the impact of climate change, 'we need to restore native vegetation in key locations,' she said.
Comprehensive, integrated watershed and flood plain management should be the state's top priority in reducing future risks, said Lt. Gen.
Ron Dardis, director of the Rebuild Iowa Office, a temporary state agency created after the floods and tornadoes of 2008.
The state has already expended more than $500 million in efforts to recover from 2008 floods, which caused an estimated $8 billion to $10 billion in damages, Dardis said.
'Can we afford to pay for disasters of this magnitude on a recurring basis?' he asked.
The Little Wapsipinicon floods Island Park in Fairbank after significant rain on Wednesday, July 7, 2010. (Cliff Jette/Sourcemedia Group)