Sunday's rains flooded out parts of Cleveland—cars were seen literally floating along Euclid Avenue, that is, if they could reach University Circle at all with multiple road closures causing a Monday morning ruckus. By Tuesday, the area dodged another episode as rain turned to snow. Before the next spring torrent arrives, let’s talk about what extreme weather events like this mean, and how much more can we expect?
If we were to examine this from a bird’s eye view, we would say, Monday’s flood is an early warning. Not only for tens of thousands of commuters to the city’s second largest employment area, but for anyone who gets their drinking water from Lake Erie, which is to say, most of us.
Cities have hydrological systems, natural and manmade ways of conveying rainwater, that are affected by how much land surface area is covered by pavement. Ultimately, the water has to go somewhere and when two inches of rain fell on Sunday, the water rushed down Fairhill and Cedar— through full sewer basins below the streets. The problem goes beyond ponds on Euclid, Stokes and Stearns Avenues, and MLK Drive. In a combined sewer overflow system like Cleveland’s, a heavy rain mixes with sewerage and the contaminants from the surface streets—human waste and surface pollution flow straight into Lake Erie.
Back to “how did this happen?” The answer, despite all appearances is, not overnight.
What is happening is a regional concern; urban professionals call it “Regime Change.” To grasp what this means, again we need to pull back and look from above at the slow conversion of land covered by forest and green fields—a natural ability to absorb rain where it falls. Over years and decades, the land surrounding and leading into the Doan Brook, which drains parts of Shaker and Cleveland Heights and Cleveland, has urbanized. The result is a regime change to the east side’s ability to handle stormwater. This is not unique to Doan Brook as the Rocky River and Cuyahoga River also flood regularly during heavy rain events.
With reports identifying heavy rain events in the Midwest as a likely outcome of climate change, climate resilience scientists like Marina Alberti would view Monday’s flood as an early warning unlikely to “go away” by themselves. She writes that cities experiencing slow regime changes like land cover that alter hydrology need an emergency preparedness mindset.
“Increasing connectivity among people, business enterprises, and governmental and nongovernmental organizations…enables communication, efficiency, and innovation,” the University of Washington professor writes in her book, Cities That Think Like Planets.
She recommends adopting the earthquake profession’s four Rs to assess our infrastructure’s readiness to withstand more shocks like flooding. We would measure our infrastructure’s Robustness, Redundancy, Resourcefulness and Rapidity.
“Early warning becomes especially valuable when dealing with irreversible state changes, as the ability to delay or prevent these changes is far more desirable than trying to force a return to the previous state,” she says.
Our current system for handling problems like flooding is to expend more energy, which may exacerbate the problem if it generates more heat-trapping carbon emissions (leading to storms packing more punch). For example, energy systems rely on communication systems which rely on energy systems.
Coastal cities need to recognize regime change and respond in kind. Flood control regimes have changed from natural—where deltas and river banks swell and move—to centralized measures.
“In urban ecosystems, feedback mechanisms that operate between ecological and human processes can amplify or dampen changes, and thus they regulate the systems’ responses to external pressures.”
In other words, innovation for regime change of this scale might be more local, hybrid and built up slowly—like the ideas in Resilience CLE, the Cleveland Tree Plan, and others who are adapting vacant land as functional green space, community gardens and soil remediation. Adding more trees, green roofs, and rain gardens throughout the Doan Brook watershed, not just in the rapidly developing University Circle area, would be part of a responsive, redundant stormwater system. So too are the patterns of land use further ‘upstream’ from Shaker and Cleveland—the source of rapid changes, such as the Chagrin Highlands and other communities converting green space that once acted as a buffer to protect downstream communities.
The Northeast Ohio Regional Sewer District is currently digging a giant tunnel for $142.3 million to intercept the polluted water from the CSO before it reaches lower Doan Brook along MLK Drive. But the volume of water flowing downhill into University Circle from the Heights and beyond will similarly need a regional solution that could start by going beyond the surface, to the source.