Daily Times

What causes floods? Top 7 common causes of flooding

Flooding occurs for a number of reasons all around the world – but why precisely does flooding occur? Flooding is caused by a variety of human factors, including poorly built infrastructure. There are numerous natural causes of floods.

Here are eight of the most common natural and man-made sources of flooding. Flooding can have disastrous repercussions.

1- Heavy Rains

Heavy rains are the most straightforward explanation for flooding. You are surrounded by infrastructure and systems intended to transfer rainwater into appropriate basins and reservoirs no matter where you live. Most of the time, the infrastructure does its job, and you never have to worry about where the rain goes when it rains.

However, when it rains heavily, however, those systems get overburdened, and the water does not drain as rapidly as it should. In short, drainage systems become clogged, and water rises – occasionally into homes. This usually happens only when there is a protracted period of heavy rain.

2- Overflowing Rivers

Flooding in your neighborhood does not always have to be caused by heavy rains. For example, if you live by a river and locations upstream suffer strong rainfall, it could cause a significant overflow where you live. Most larger rivers have a number of dams to help control heavy rains, and most river systems are regulated by government bodies.

However, those authorities must sometimes make difficult judgments about how to operate dams. They can often regulate the water and prevent flooding, but not always.

What causes floods? Top 7 common causes of flooding

3- Broken Dams

Much of our infrastructure was built years ago, so it is getting old. When heavy rains come, and water levels rise, aging dams can fail and unleash torrents of water on unsuspecting households.

While we have come to depend on 20th-century architecture, and much of it does its job well, there is always a possibility that a structure will fail.

4- Urban Drainage Basins

Many of our cities are made of mostly concrete and other impermeable materials. When you have an urban drainage basin that is made of concrete, there is no ground for water to sink into. So, when those drainage basins fill up, it is going to mean flooding for low-lying areas.

This is mostly the case in large urban areas — think Houston and Los Angeles. When heavy rains strike, the basins used to drain them cannot always handle the load.

5- Tsunamis

Rain is not always the culprit when it comes to flooding. Storm surges related to hurricanes and other storms can lead to significant flooding, as can tsunamis that are sometimes caused by underwater earthquakes.

Given modern technology, we often know about storm surges and tsunamis before they arrive, but this is not always the case. For example, in 2004, an earthquake off the coast of Indonesia created a tsunami that gave little warning before coming ashore.

6- Channels with steep sides

Flooding often occurs when there is fast runoff into lakes, rivers, and other reservoirs. This is often the case with rivers and other channels that feature steep sides. It is a similar issue to having a lack of vegetation, which is explained in more detail below.

7- A lack of vegetation

Plants can help to decrease runoff and prevent flooding. However, when there is a paucity of vegetation, there is little to prevent water from running off. Following a drought, this can be a bit of a conundrum.

While residents in the area are likely to enjoy the rain, the absence of greenery following the drought might lead to flash flooding. This does not always happen when basins and reservoirs are nearly empty, but it can happen in circumstances of heavy rainfall after extended periods of drought.