Army engineers warn of brutal future for Ohio River region from climate change

Climate change will push the Ohio River and its tributaries into uncharted waters, setting off economic and environmental crises like never before across a 13-state region.

That's the conclusion of a new U.S. Army Corps of Engineers report that hits close to home. It found that flooding, drought and power failures could become more frequent in Kentucky and Indiana — and the rest of the Ohio River basin.

"The changes are happening today," said Kathleen D. White, a climate change expert at the Corps headquarters who oversaw development of the study. "This isn't something that's just in the future."

Related: Defense Department study on Ohio River's future flies in the face of Trump's climate views

More: Louisville may require homeowners to replace lost street trees

The study makes the case that a healthy Ohio River is essential to the United States for industrial manufacturing, power generation, drinking water supplies, transportation of goods through a network of locks and dams, recreation and maintenance of the natural world.

"This is a major river in the heartland of the United States," said Paul Kirshen, professor of climate adaptation at the University of Massachusetts Boston, and one of the report's authors. "It contributes a great deal to the (economy) of the region and the environment of the region. And it is going to be pretty severely impacted by climate change."

The study concludes that the most dramatic effects are likely two decades away. But changes are happening more quickly than previously thought, and the time to start bracing for "a new normal" and making plans to adapt is now, White said.

More: Boycott of Ky. products could send state from 'dirty' to green, says climate expert

The document is intended to help the 27 million people who live in 2,400 urban and rural communities across 204,000 square miles understand that the Ohio River and its tributaries will not escape climate disruption.

Among the findings:

► Increasingly potent storms will cause river levels to surge, risking major floods in low-lying cities like Louisville.

► More frequent and heavy droughts will likely dramatically reduce river volumes in some spots, putting in jeopardy drinking water supplies, barge traffic and power generation that relies on abundant water.

► Rising temperates and wild swings in river flows threaten to wipe out fish and other aquatic life.

► Economic losses could be ten times or more greater than from any other resource-based threats from the past.

The report is the first of its kind for the Ohio River basin.

It also recommends what can be done to adapt. The suggestions include retooling how reservoirs are managed, re-evaluating flood protection systems based on changing weather patterns, modifying power plant operations, and making cities more like sponges for rain instead of funnels.

Because construction and other efforts to help the region adapt can take years to fund and develop, White said: "These are exactly the kinds of things people need to know now."

The report is especially timely, said University of Louisville engineering professor Thomas Rockaway, who was not involved in the study but is familiar with its findings.

"There is a serious problem with our infrastructure," Rockaway said. "With these projections, it looks like they will be taxed even more."

The study, he said, is a reminder that "we live (on) a dynamic planet. Things change, and we have to be ready to adapt to those changes."

Protecting assets

A team of 18 experts from inside and outside of the Corps worked on the study, starting in 2009. It was published earlier this year, even as President Donald Trump was pulling the United States out of an international agreement to fight climate change, which scientists largely blame on human activities, and his Environmental Protection Agency has been scrubbing its website of references to climate change.

While Trump has called climate change a hoax and promises to boost coal, a major source of heat-trapping pollution, the U.S. military continues to see climate threats.

White said the Corps is required by law to anticipate all changing conditions. "These are changing conditions," she added.

Another bigger study – the latest National Climate Assessment – in November pinned the problem squarely on people, concluding that "for the warming over the last century, there is no convincing alternative explanation supported by the extent of the observational evidence." It was written by scientists from 13 federal agencies and peer-reviewed by the National Academies of Science.

For its part, the Corps was concerned about how a changing climate might affect an extensive network of facilities and projects that manage or use waterways, said the report's lead planner, Gus Drum, a retired Corps official out of Huntington, West Virginia.

More: Hemp is 'the next big thing' in pain management as growth and research expand in Kentucky

Those assets are in a basin that extends from New York and Maryland to Tennessee and Illinois, including nearly all of Kentucky and most of Indiana. It's home to 27 million people.

There are dozens of locks and dams on rivers, more than 100 systems of levees and floodwalls, and 109 large dams and reservoirs, providing river navigation, flood control, hydropower and recreation.

The Ohio River alone provides drinking water to 5 million people, including nearly 1 million supplied by the Louisville Water Co.

"If we were going to experience changes in air temperature and changes in water temperatures and changes in rain and streamflow," Drum said, "would they affect the Corps' ability to operate and maintain facilities and to perform their missions?"

The answer was yes.

The study was based on 2007 modeling from the Intergovernmental Panel on Climate Change and is broken into three 30-year time periods, ending in 2099.

Weather extremes will drive substantial variations in river flows across the basin, the study found.

More: Jackie Green to run for mayor in 2018, campaign on fight against climate change

For example, areas northeast, east and south of the Ohio River are expected to see as much as 50 percent more precipitation, with resulting higher tributary stream flows.

Conversely, those areas north and west of the Ohio River are expected to have more periods of decreased precipitation, especially during late summer and autumn, resulting in as much as 50 percent lower tributary stream flow.

But the study found that even those areas where drought will be more common will need to brace for flooding because of the increased likelihood of more intense storms.

"The potential impacts to infrastructure, energy production, and both aquatic and terrestrial ecosystems ... range from minimal (in some areas) to dramatic and potentially devastating in others," the report concludes.

Flooding fears

Of particular concern, the report identifies 400 power plants, many of which rely on abundant cooling water to meet national energy demand. It concluded that cool water could become too scarce at times for some power plants to function, especially in the later decades of the study.

Natasha Collins, a spokeswoman for LG&E and KU Energy, said her company was not familiar with the Corps study.

However, she said the utility's planning process takes into account a range of anticipated changes, "including daily weather variability for each of our service territories, the likelihood of extreme weather events, as well as any changes in generating technology and its impact on our generating fleet."

More: Louisville Water Co. to raise your rates again, starting Jan. 1

Corps officials said cities like Louisville that tap directly into the Ohio River for drinking water may be better positioned for their supplies than those that tap smaller surface water sources. Still, the study noted that previous droughts had dried up some municipal water supplies across the basin, and climate change could "create continuing emergency situations" for them.

Decreased rain would also hurt some communities that rely on wells, the Corps found.

"We are doing all we can right now to strategically work with local communities and partners to mitigate the risks of an uncertain climate," said John Mura, a spokesman from the Kentucky Energy and Environment Cabinet.

The cabinet's Division of Water, for example, has been integrating its water resource programs, updating drought and flood risk assessments and developing mitigation plans.

Greater river flows mean higher waters and increased risks that a floodwall or levee could be overtopped, resulting in potential loss of life or economic damage, the study found. Pumps could also be overwhelmed, it concluded.

"Cities everywhere near water bodies, whether near lakes, the ocean or rivers are facing these same problems, of what they need to do about existing flood management infrastructure that's weakened by age or not properly maintained, and will be further stretched by climate change," said Kirshen, the Massachusettes professor.he said.

That's a critical issue in the Louisville area.

Read this: Find out what is true and false about climate change

Louisville's Metropolitan Sewer District, for example, is responsible for maintaining a 29-mile system of levees, flood walls, 16 flood pumping stations, 150 floodgates and 80 floodwall closures.

The system was built after the devastating 1937 flood, and MSD has called for hundreds of millions of dollars in upgrades. It's also incorporating climate change predictions through at least 2035 into its engineering designs, said Brian Bingham, a senior engineer at MSD.

It is unlikely Louisville would need to raise flood walls and levees, said John Bock, chief of engineering for the Corp's Louisville District. He said MSD does a good job of maintaining its flood protection system.

But he added: "When you get to the point where pumps in the system are 60 or 70 years old, it becomes an issue. They may be near the end of their life."

MSD has wrapped a variety of projects including work on 15 flood pumping stations into its 20-year, $4.2 billion Critical Repair and Reinvestment Plan. But the 20 percent rate increase designed to pay for that plan has been blocked as too costly by the Louisville Metro Council.

That's not uncommon across the nation, said Kirshen. "Citizens are reluctant to pay," said Kirshen, who is advising Boston on how to brace for climate change.

But paying now for adaptation can be as much as 20 times less expensive than the costs of a damaging major flood, he said. "You don't want that," he added.

James Bruggers: 502-582-4645; jbruggers@courier-journal.com; Twitter: @jbruggers; Support strong local journalism by subscribing today: www.courier-journal.com/jamesb.

KEY FINDINGS

HOTTER: Louisville could see a 12.5 percent increase in its mean annual temperature from about 56.9 degrees in 2020 to 64 degrees in 2099. That's even hotter than Houston, now.

HIGH RIVER: Bigger storms may cause average annual water levels in the Ohio River at Louisville to surge as much as 15 percent through 2040 and up to 35 percent by the end of the century. Flooding is more likely.

WIDE SWINGS: Overall, waterway levels in the basin will likely experience bigger extremes during the wetter month of March and the drier month of October.

SPRING SOAKING: The Ohio River in March at Louisville could see levels up to 15 percent higher by 2040, and 35 percent higher toward the end of the century.

FALL DRYING: Increasing drought after 2040 across much of central and southern Indiana, Kentucky's Bluegrass and portions of Eastern Kentucky, will cause the levels in Ohio River tributaries to be down by as much as 35 percent; after 2070, those Kentucky regions could see water levels down even more, to 50 percent.

KEY RECOMMENDATIONS

Fix flood control dams that are in poor condition.

Modify reservoir operations and policies.

Restore wetlands, which can soak up rain.

Reconnect floodplains to their rivers, allowing for natural flood storage.

Water conservation at farms and in cities.

Build more storage basins to collect rain.

Reduce the amount of hard-packed surfaces that repel water.

Turn to so-called "green infrastructure" to make cities more like a sponge, to reduce flooding and replenish groundwater.

Develop or update drought contingency plans.

Modify thermoelectric power plant cooling systems.

Better manage pollution washing off farms, cities and abandoned mines.



