Scientists have been warning us for years that as global warming progresses, we can expect extreme weather events to become more common.
The impact of Hurricane Harvey [Photo by the South Carolina National Guard]
The flooding caused by Hurricane Harvey is a “500-year” flood, meaning that it had a one in 500 chance of happening in any given year. However, it's the third 500-year flood to occur in Houston in the past three years. Thus, it's possible that rare weather events such as this are becoming more and more common. If this is the case, we can't really do anything to stop hurricanes or massive storms. However, what we can do is take necessary measures to reduce the impact of natural calamities on our cities.
Not to oversimplify an obviously complicated problem, but for our purposes, we can boil it down to dos and don'ts. There are certain things that we shouldn't do if we want to reduce the impacts of floods, but there are also things that we can and should do.
The aftermath of Hurricane Katrina in New Orleans
Let's look at Houston as an example. According to the firm Risk Management Solutions, the losses from Harvey could reach $70 billion to $90 billion. Most of these losses are due to the flooding in Houston. The question now is how did it come to this?
Houston is a large city that doesn't have zoning regulations. Over the decades, the city expanded and cemented over wetlands and swamp lands. Unsurprisingly, this has taken away the land's ability to absorb water. Add to that the fact that the city's decades-old flood control system dates back to the 1940s.
Also, Houston and over 600 other places in the United States have storm sewers and wastewater sewers that have the same piping. This means that when storms and floods come, raw sewage can go into open waterways, which can be a public health hazard.
Now let's look at Copenhagen. The Netherlands has been working to hold the North Sea back for centuries. In 1953, a massive storm destroyed dikes built to keep the sea away and the resulting flood killed 1,836 people. Barricading the water—fighting against it—obviously didn't work in the case of extreme weather events. However, the Dutch found a better way of dealing with possible flooding.
Another reason to save the wetlands
The Dutch approach is to allow the water to flow freely where it can't damage anything. Copenhagen and the rest of country have ponds, lakes, and parks that can contain water when there's a threat of flooding. In the wake of Hurricane Katrina, New Orleans took a similar approach. The city built a resilience district with features that can capture rainwater and prevent flooding.
Nature can be destructive, but we can also fight nature with nature. In the case of Houston, for example, paving over wetlands was a bad idea. According to this study, coastal wetlands prevented $625 million in property damage during Hurricane Sandy.
Thus, it's best to have pockets of nature that can deal with what nature can dish out. Extreme weather events are set to become more common, so we need to look at where we live and think about what needs to happen in order to protect ourselves from the worst impacts of natural disasters.
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