Urban flooding occurs when water flows into an urban region faster than it can be absorbed into the soil or moved to and stored in a lake or reservoir. It can be caused by flash flooding, coastal flooding, river floods or rapid snow melt.
On Tuesday, the Madison area experienced urban flooding caused by an intense rainfall. On that day, a daily record rainfall of 1.46 inches fell at Dane County Regional Airport, breaking the city’s previous May 27 record of 1.27 inches. The city sewage system and draining canals did not have the necessary capacity to drain away the large amounts of rain that fell in a short period of time.
Flash floods occur suddenly, and the water can flow quickly. Urban flooding is most often an inconvenience, particularly when it occurs during commuting time as Tuesday’s did, but it can also be dangerous.
Never drive your car across a flooded road. The economic cost of urban flooding can also be high, as water damage to homes and buildings can be very expensive to repair.
Urbanization of the United States and other countries is increasing. Common consequences of urban development include the removal of vegetation and an increase in impervious surfaces and drainage networks, all of which increase precipitation runoff into streams and rivers. This may result in more flooding.
Urban planning explores design strategies that include storm water conveyance systems and other methods to prevent flooding. This long-term planning must include forecasts of expected weather. Current research indicates a trend to more intense precipitation, which could result in more urban flooding if it’s not properly planned for.