As a result of climate change, flash floods have become more widespread, devastating cities all over the world. After heavy rains in July, much of London and the south of England were flooded. Flash floods occur when there is a lot of rain; the amount of water is too much for the drains and sewers to handle. It can strike without warning and at any time. Floodwaters can block roadways, forcing people to abandon their cars and causing damage to their homes and businesses.

Floods can damage critical public structures such as transportation networks and hospitals. After losing power, some London hospitals were forced to evacuate patients. Because of hard surfaces such as stone front gardens, roads, parking lots, and high streets, this type of “surface water” flooding is more common in large cities. Rain does not go into the ground in the city, as it does in the rural. In July, for example, Hurricane Elsa severely damages New York City, flooding the subway system.

“If the roadway drains can’t handle the water, it pours over the curb and adds to the problem,” observed Sarah Feinberg, president of the city’s transportation authority. She claimed that water had gotten into the subway vents and down the stairway. Many countries, including much of the United Kingdom, built ancient sewer systems based on rainfall forecasts from the past. According to Dr. Veronica Edmonds-Brown of the University of Hertfordshire, London’s development is an issue since the city’s Victorian-era drainage infrastructure “cannot cope with the massive rise in population.”