How To Prevent Flooding – For Good!
News of flooding is becoming increasingly regular. As our towns and cities grow, the risk of flooding increases as aging infrastructure can no longer cope with the drainage demand. Over the past few weeks following a period of prolonged stormy weather, the ever present threat has become a living nightmare for many communities around the UK. Homes have been destroyed and lives completely upturned. With weather systems becoming more unpredictable and extreme weather events expected to become more frequent, is flooding something we have to learn to live with? The most effective flood protections systems involve layers of protective and preventative measures. Many of which need to be undertaken at a national level, but communities and even individuals can and should play their part.
Perhaps the best place to look for flood prevention technology is the Netherlands. With 60% of the population living below sea level, the Dutch have developed some of the most sophisticated flood control systems in the world.
dutch flood preventions
Deltawerken or Delta Works, is a network of dams, sluices, locks, dikes and storm barriers. This complex drainage system also provides one the country’s most famous features, the canals. Perhaps the most impressive feature of the Deltawerken is the Maeslant Storm Surge Barrier. Constructed in 1997 it is one of the largest movable structures on the planet.
Closer to home, the Thames Barrier, is a movable flood barrier, made from hollow steel water gates. The gates can be opened to allow shops through, then when needed they revolve shut to prevent water flowing through, keeping the Thames River to a safe level.
Sustainable Urban Drainage Systems (SUDS)
Flood barriers and canals have been proven to be very effective in preventing floods, but these projects can only really be carried out at a national level. There are things that communities and even individuals can do to minimise the risk of flooding. People often complain that we have hosepipe bans in the summer, then perhaps within just a few weeks those same communities face the risk of flooding. Why is this? As more and more of the country is paved over there is less surface area for rainwater to be absorbed. Instead rainwater run-off is washed away into drains.
This causes three problems:
1. Pollution from road surfaces washes into water systems
2. Less water is absorbed into the ground to replenish reservoirs
3. In stormy weather drainage systems quickly become overloaded, increasing the risk of flash flooding.
SUDS is a different kinds of drainage system which incorporates porous surfaces, swales, ponds, and green roofs to allow rainwater to soak into the ground, rather than run off into drains. Any pollutants are filtered out into the ground, rather than going into the water system and this cleaner water eventually ends up in reservoirs, so there should be less chance of a hosepipe ban. SUDS can be a very effective part of the flood management system, but while many features can be adopted by individuals, it really needs to be adopted at a community level. So what can individual house holders do?
Rainwater harvesting is something that can be done by most households, with virtually no outlay. At its most basic a rainwater harvesting system can be a large tank connected to the downpipe to collect rainwater from the roof. This water can then be used in the garden and is especially useful during dry summers. More advanced systems can involve underground tanks which can store water for use around the house, for example to flush toilets, or even to be used in washing machines. One person adopting a rain water harvesting system is unlikely to make a lot of difference, but when hundreds, or even thousands of people take up these systems it can have a huge difference.
alternative to sandbags for flooding
Rainwater harvesting can help to reduce the risk of flooding, but if the worst happens you need something to protect your home. Sandbags have been the traditional defence for homes in high flood risk areas. Fluvial have developed a more effective flood brick, which is easier to use, easier to store and re-usable. The flood brick has recently won funding from Defra in a Dragons Den style competition. The bricks fill with flood water, using the waters own weight to hold back the flow.