This year was an odd one for Ohio, weather-wise.
We saw tornadoes in February, April, and May, flash flooding in June and July, and an early season snowfall in November. This spring, Cleveland saw rain on 55 out of 93 days, making it the wettest we have on record. Scientists are calling the rapid shift in weather conditions from one extreme to the next “weather whiplash,” and it may be that climate change is a contributing factor.
As communities experience more frequent intense weather, scientists and policymakers are turning their attention to how climate change will affect the water cycle and the bodies of water in their communities.
How will the Cuyahoga River and its tributaries stand up against these changes, and what effect will they have on the 33,000 Ohioans living in the river’s floodplain? Let’s see what the experts have to say.
Climate change 101
Lauren Kinsman-Costello, an assistant professor of biological sciences at Kent State University, says the best metaphor she’s heard for climate change referenced the steroids scandal that rocked Major League Baseball in the late 90s. “You wouldn’t say steroids made Sammy Sosa or Barry Bonds hit a home run. But overall, steroids made them hit more home runs, and each home run was potentially more powerful.”
“Climate change is like putting the weather system on steroids,” she said.
Here’s the way climate change works, in a nutshell: Humans use fossil fuels to run our vehicles, heat our homes, and produce our electricity. Using fossil fuels emits carbon into the atmosphere, and carbon traps heat in the air along with other molecules, like methane. Normally, this is a good thing. Without these heat-trapping molecules, the warmth from the sun would bounce off the earth and back into space like it does on Mars, which has no atmosphere.
The earth has natural heating and cooling mechanisms that keep the atmosphere in balance, but when molecules trap more heat than the earth is able to cool, temperatures rise. Rising temperatures generate more frequent and intense weather events such as heavy downpours, flooding, heat waves, and droughts.
Dramatic shifts in weather patterns won’t happen immediately, Kinsman-Costello said. “When we talk about climate change, we’re talking about changes in averages over long-term cycles, not just day to day.”
Climate change and the river
Think of the Cuyahoga River Watershed as a giant sink with a faucet and a drain. When the faucet is turned on—that is, when it rains—the water has to go somewhere. In the watershed, some of it seeps into the earth to become ground water. The rest of it runs to lower ground and drains into streams, rivers, and lakes. The Cuyahoga River Watershed drains water from 813 square miles and six counties: Cuyahoga, Geauga, Medina, Portage, Stark and Summit.
Kinsman-Costello, who specializes in hydrology, the branch of science concerned with the properties and movement of the earth’s water, said that more frequent and intense rain events will directly impact the river. In the future, we may see “higher highs” and “lower lows” in the Cuyahoga’s levels and ultimately have “less of an ability to predict what is going to happen in the future based on what’s happened in the past.”
“There’s going to be fewer ‘normal’ years, in a sense,” Kinsman-Costello said. “I’ve heard people say, ‘It’s not even a new normal. It’s a new weird. The new normal is weird.’”
When precipitation is unpredictable, so are flow rates of a river. Every important thing about a river can be determined by its flow rate, which measures how much water is flowing in a river and how quickly it is flowing. Flow rate determines a river’s shape and direction, the chemical makeup of the water, which organisms are fit to live there, and the stability of its banks. In the long run, a change in flow rates could mean the Cuyahoga will be a very different river from the one we know today.
Intense storms in urban watersheds
Further complicating the issue of heavier and more frequent rains is the fact that some of the Cuyahoga passes through suburban and urban areas. Jennifer Grieser, the Director of Natural Resources for the Cleveland Metroparks, said Cleveland’s abundance of concrete can sometimes cause flooding.
Typically, in natural areas like forests and meadows, rainwater soaks into the ground and flows out into streams and rivers slowly over time. Urban watersheds have much greater amounts of impervious surfaces, which means there are more roads, roofs, parking lots, driveways, even grassy lawns with compacted soil that don’t allow water to infiltrate, so the excess runoff flows off the surfaces and runs downstream rapidly. “When the water is flushing directly to the river through networks of storm drains, the river feels those extreme events even more intensely than it would have if the rain was falling in a forest and the water could work its way through the soils. The delivery would be slower,” Kinsman-Costello said.
Grieser and the Metroparks staff see the effects of impervious surfaces during heavy storms in West Creek Reservation in Parma, a tributary of the Cuyahoga River. During a heavy rain, water runs off the roofs, driveways, and streets of the residential neighborhood near the park and rushes into the catch basin. Then the storm sewers outlet into West Creek. “It’s not like the water stops at the boundary of the residential neighborhood,” Grieser said. “Stormwater doesn’t heed political boundaries. It’s going to run downhill, no matter what.”
Pat Gsellman, project manager for Akron Waterways Renewed, a program within Akron’s government dedicated to overhauling the sewer system, said the runoff from huge storms can overwhelm the sewer system, causing combined flows of stormwater and sewage to flow into relief points along the river. “During the peak flow of a rain event, we can get up to 280 million gallons a day at the plant.” Any more than the 280 million gallons is partially sanitized before being routed into the river.
Flooding doesn’t just affect humans. Kinsman-Costello said natural disturbances where rivers move fast and “reset the clock” on algae growing on the rocks, the bugs that live in the algae, and the fish that eat the bugs are a normal part of the river’s life. “But climate change might be changing the patterns of those really high flows and make it difficult for certain kinds of communities to stay there,” she said.
“Flooding isn’t necessarily a bad thing,” Grieser said. In an ideal situation, rivers and streams would have natural riparian buffers, areas along their banks with trees, shrubs, and grasses that control erosion, collect pollutants from runoff, and provide nutrients to the stream and habitat to organisms living there. The problem comes when riparian zones are forced to narrow in order to accommodate parking lots and buildings.
“When a bunch of water that’s confined to a narrow channel picks up sediment and has got all this energy, it’s got to get rid of it somehow. If the water can get out onto a floodplain and lose that energy, that then decreases downstream erosion,” Greiser said.
While it’s normal for stream banks to experience erosion, certain circumstances can exacerbate that process, especially in urban areas.
“In a lot of urban settings, with the lack of appropriate municipal codes, people have been allowed to build structures right next to a stream, so then you have entities like the Northeast Ohio Regional Sewer District spending millions of dollars to stabilize stream banks and protect properties,” said Greiser.
Scott Hardy, an extension educator with the Ohio Sea Grant Program with a PhD in Environment and Natural Resources, said increased erosion could have a huge impact on people’s daily lives. “When the banks of the river and its tributaries erode, they take land with it,” he said.
“If you are a business that has any sort of frontage on a river, stream, or lake, and your land erodes, you’re literally losing your business,” Hardy said. “And if you have sidewalks, bike paths, bridges, or culverts that erode away, you’re taking away transportation from residents who need it to shop for food and get to health care.”
Another concern for the watershed is drought. In urban watersheds, impervious pavement does not allow water to drain gradually into streams overtime, which means smaller streams can dry up during the summer months when there is less precipitation. As temperatures increase and water evaporates, smaller streams that are permanent may become ephemeral.
“Prolonged drought—year after year of stress on the river—is going to impact the plants and the trees surrounding the stream,” Grieser said. “If they die, then you lose the shade next to the stream. If you lose the shade next to the stream, the water warms up. There’s all kinds of cascading impacts.”
Working toward solutions
Fortunately for us, organizations across Greater Cleveland are enacting plans to address the problems climate change may create.
The City of Akron is midway through an overhaul of its sewer system that will reduce the amount of stormwater and sewage routed into the river annually from 2.4 billion gallons to 75 million gallons, thanks to the addition of a 6,300 foot tunnel and five giant concrete tanks that can hold millions of gallons of excess overflow. The city is also adding green infrastructure in an effort to “control the weather before it gets into the [sewer] system,” Gsellman said.
Some of the green infrastructure projects are straightforward, such as converting empty lots where abandoned buildings once stood into wetland areas that can absorb runoff that would otherwise flush straight into the sewers. Other projects are more complicated, such as the renovation of Aqueduct Street, which involved building an infiltration system below the street, repaving it with pervious pavement, and narrowing the driving lanes to make space for bioretentive tree lawns that collect rainwater.
Grieser said in the past decade, the Cleveland Metroparks have “really ramped up” their stormwater retrofit projects. “We’ve gone back to older parking lots and added in various stormwater control measures such as pervious pavement, detention basins, or stormwater wetlands to catch the runoff,” she said.
Stormwater wetlands and detention basins work like giant Brita filters. “Say there is runoff with excess phosphorus that came from fertilizer. The water filters through the soil, and the phosphorus clings to that soil, so that when the water comes out of that practice, it no longer has the phosphorus.” These stormwater control measures don’t just catch runoff. They improve water quality.
Grieser said she and her colleagues within the Cleveland Metroparks Natural Resources Division subscribe to an adaptive management philosophy. “We’re never going to know everything [that could happen in the future], but we can’t get stymied by what we don’t know. We use our current data and resources to the best of our knowledge. We make decisions. And we continue to monitor our impact, see whether or not we’re successful, and adjust.”
Climate change isn’t the only problem watershed managers are contending with, Grieser said. “There’s also new contaminants, whether its excessive road salt and therefore conductivity in our waters or there’s pharmaceutical research and other emerging pollutants. We try to stay aware of that research and those trends.”
Kinsman-Costello said scientists are uniquely positioned to explain climate research and advocate for action. “But it’s always important for scientists to be clear when they’re wearing their advocate hat,” she said.
Hardy said seeing the work others are doing makes him optimistic about what’s ahead. “There is a really good network of individuals and organizations that are dedicated to addressing a lot of these challenges as they come about, so I’m hopeful that, due to the people in place, we will be able to weather the storm.”