Mayor Curt Zimbelman of Minot, N.D., sat in his office yesterday for the first time in more than a week after battling the worst flood of the Souris River his town has seen since 1881.
Zimbleman oversaw an emotional, voluntary evacuation of his town when the crests last week were forecast to be 7 feet higher than they have ever been. He has taken numerous helicopter rides to survey the inundation's damage. He is overseeing a secondary levee that is holding water back for emergency vehicles and trying to find shelter for Minot's 11,000 displaced people.
Zimbelman said he knows climate change could create more flooding and even drought someday in his city. But he is not thinking about that now.
"It's complete devastation. Most of these houses are up to the rooftops," Zimbelman said, recounting his observations from hours spent at the emergency center and surveying the damage by helicopter. "Right now we're just focused on getting through the immediate disaster."
This year, record amounts of snow and rainfall resulted in unprecedented flooding of the Souris and Missouri rivers, wreaking millions of dollars in damages in North Dakota towns like Minot and states throughout the Midwest. The U.S. Army Corps of Engineers braced for crisis along the Souris on Father's Day, with severe flooding setting in June 24. Last weekend the river crested, some areas reaching 14 feet above flood level.
With thousands of people displaced and homes swallowed by the river, it is hard to imagine the midwestern United States could soon be experiencing water shortages. But a paper published earlier this month in the journal Science, shows that in the coming years the trend will be toward uniformly increased temperatures and less snowfall in the north. The research was based on 66 tree-ring chronologies showing data back to the 1200s. Ultimately, this could result in lower peak streamflows in headwaters feeding the Missouri, Columbia and Colorado rivers.
"The past 30 years have been unusually warm across the northern Rockies compared to the last 800 years," said Gregory Pederson, research ecologist for the U.S. Geological Survey and lead author of the paper. "What's worrying is that it may indicate a point when we have generally synchronous decline [of snowpack] across the West."
Pederson noted that this year's extreme weather patterns underscore the difference between weather and climate. The extremely wet and cool conditions causing greater snowpack in the north and particularly dry conditions of the south fall into the La Niña weather pattern. But the seasonal La Niña and El Niño weather patterns are also being acted upon by climate change, with global warming as the driver, which can make events associated with these patterns, like dryness or flooding, more intense.
In Pederson's long-term research on climate trends he found that warming of the planet reinforced by human activity could actually limit the water supply throughout the West. That could affect the more than 70 million people who depend on the runoff from snow in the Canadian Rockies.
"If the forecasts for warming climate in the future are right," said Pederson, "we should see more precipitation coming in as rain rather than snow, earlier melt of snowpacks and basically a longer dry season without the free storage of snowpack and the ability to manage water resources."
While mayors, politicians and engineers battle today's floods, Pederson predicts water managers are going to have to deal with two longer-term issues: the increasing demand for water to accommodate a growing population in the West and the way in which climate change will affect the water supply.
Managing the flood gates, now and in future
Managing the watersheds fed from the north has always been a balancing act. Jody Farhat, Army Corps chief of water management for the Missouri River Basin, knows this too well.
Recently, she has come under criticism for the way she has handled the six dams along the Missouri River as severe flooding ravages the surrounding area. Some residents and politicians have blamed the Army Corps for following their master manual too closely, and not lowering reservoir levels enough in anticipation of high precipitation. But Farhat says this year was "a perfect storm" and that a very late peak of snowpack coupled with heavy rains made it impossible to capture all of the runoff.
She added that the Missouri River must also serve eight congressionally mandated functions: flood control, navigation irrigation, hydropower, water supply, recreation, fish and wildlife, and water quality. Only flood control, she said, requires there to be empty space in the reservoirs. All others require that water be released or held in the reservoir.
If Pederson's research proves accurate, water managers like Farhat will struggle to fulfill the river's functions due to water shortages. Farhat said she believes the dams along the Missouri, which control the water resources of at least 3.1 million people, are prepared to meet that challenge.
"We have a very robust operating plan for the main reservoir system," she said, noting that three of the agency's largest dams along the Missouri River contain half of the storage for drought periods for the area that the system supports.
"We have operational studies going back more than 100 years showing that we can manage drought like the one during the Dust Bowl," she said.
In the meantime, Farhat is mitigating the damage of this year's flood and bracing for whatever comes next. She admits that high levels of variability make planning difficult.
"We don't know if this year is an outlier of if there was a changed climatic condition that makes this more of a trend," she said.
A Pew Center on Global Climate Change report published yesterday claims there is a trend toward more natural disasters as a result of climate change.
"By increasing greenhouse gases in the atmosphere ... we are loading the dice toward more favorable climate conditions for extreme weather and are very likely to experience more frequent extreme events over time," the authors wrote.
Jay Gulledge, senior scientist and director at the Pew center, said it is impossible to isolate one flood or disaster event and try to link it to climate change. Rather, the accumulation of data showing warmer years over time proves that climate change is changing the odds of extreme weather events. Consequently, Americans needs to start thinking about these hazards and how they can be managed.
"Many of the types of events climate change raises the odds of are understood -- heat waves, wildfires, drought in certain places and floods in others," Gulledge said. "We know how it changes the risk profiles for these things and there's no reason we can't use that information to prepare for those risks."
Mayor Zimbelman said that this year's flood was so unprecedented Minot could not have done anything differently. "There's no way to prepare for it," he said. "All we can do at this point is fight the fight."