A flood defence system provides protection against flooding, preventing damage to buildings, homes and gardens. These systems can be either permanent or temporary. Some permanent defences include sandbags, dikes and embankments. The other type of defences are ‘engineered defences’, including barriers, levees and pumps. These are designed for specific hazards such as river, surface water and coastal storm surge flooding. The term ‘engineered defences’ can also be used to describe non-structural methods of flood resilience such as floodplain management, wetlands and afforestation.
During a flood, the pressure of flood waters can force doors and windows open, creating a hole or leak in your property’s structure. Often this can cause serious damage. A simple solution is to fit a flood barrier around the bottom of your door. These flood barriers create a watertight seal to prevent flood waters entering your home.
Many of these barriers can be bought at hardware stores or online. They are easy to install and can be positioned at the bottom of your front or back door. The cost of a flood barrier is less than the cost of repairing and replacing damaged goods and home furniture.
In areas that are frequently prone to flooding, long-term investment in flood prevention is needed. These investments protect homes, businesses and communities from high costs associated with flooding. They also reduce the burden on local governments, utilities and emergency services to deal with the aftermath of a major flood.
The construction of engineered defences can be broken down into three categories; fixed, demountable and temporary. Fixed defences are usually larger schemes protecting several properties; demountable defences can be moved between different locations and temporary defences can be deployed at individual property level.
The Delta Works in the Netherlands is one of the largest movable flood defence projects in the world. This project includes a number of surge barriers, with the Oosterscheldekering being the largest. The Thames Barrier is another large movable flood barrier that can be raised to protect central London from high tides and storm surges coming up from the sea. When raised it can hold back 3.6 metres of floodwaters. The barrier can be lowered at ebb tide to release the back up flood water.
When not in use the flood barrier can be hidden within a specially-designed enclosure. This means it is unobtrusive during dry days, but can be quickly activated during a flood warning. This can be done manually with a push button, or automatically using sensors that detect rising flood waters.
In addition to reducing the impact of floods, a well-designed flood defence can also provide ecological benefits. For example, by establishing flood plains and wetland systems it is possible to increase biodiversity. These areas can support grazing animals and wildlife, and also act as a natural filter for polluted water.
As we see with the catastrophic failure of New Orleans’ flood defences during Hurricane Katrina, the cost of not investing in a reliable flood defence system can be huge. Our flood defence systems are cost-effective and quick to deploy, reducing the time it takes to prepare your home for flooding.