The UK has seen unprecedented levels of flooding in recent years and we're being warned of more disasters to come. So, something must be done to protect people and property, explains Peter Jennings, Technical Director for ACO Building Drainage.

Over the last decade, Britain has experienced a significant increase in the frequency of heavy rainfall, leading to more surface water flooding, which, as a result, has caused devastation in recent years. Take 2007, which saw the wettest summer since records began in 1766 causing extensive flooding in parts of England, especially in South and East Yorkshire, Worcestershire, Gloucestershire and Oxfordshire.

This particular incident rapidly turned into a catastrophe, which caused substantial flooding to some 48,000 homes and 9,000 businesses, costing the country a total of £3.2 billion, as well as 400,000 lost school days. The resultant disruption, economic loss and social distress was still felt for years following the disaster, with as many as 168 people still being displaced and living in temporary accommodation according to government statistics that were released in July 2009.

Then, more recently, in November 2010, the floods hit again, this time in Cornwall, which saw more than 100 homes being evacuated and people being trapped inside their cars and homes, as the floodwaters rose to 6ft in the worse hit areas. Train services in and out of the county were disrupted by landslides, and schools and businesses were forced to close their doors. Hundreds of people also sought refuge in a local leisure centre, which had taken on the form of an emergency shelter, supported by aid from an international disaster relief charity.

In light of these events, experts are now warning that the UK is at more risk of flooding than ever before, with estimates putting one in six properties in England and Wales in danger, translating to a staggering 5.5 million buildings. Of these, it is estimated that around half of all residential property flooding is caused by backflow from public and private sewers, with the number of incidents being on the increase. However, some experts believe this figure could be much higher and that actually one in four homes in the UK are currently at potential risk from flood. Furthermore, a recent climate report predicted that the number of homes at risk is likely to double over the next 25 years.

What is perhaps more worrying is that recent headlines have suggested that some of Britain's biggest banks are refusing to renew flood insurance, in spite of a government agreement with the insurance industry to protect more than half a million properties at risk. As a result, the value of these homes is decreasing rapidly and home owners and property professionals are having to shave tens of thousands of pounds off their asking price in order to secure a sale.

Furthermore, this lack of insurance means that many vulnerable property owners will not only have to suffer the devastation to their home, belongings and lives, but will also have to bear the full cost of the aftermath of a flood themselves. Considering that the average cost for repairing a flood damaged house can range from £20,000 to £30,000, some property owners will simply be unable to foot the bill, leaving them with little hope for the future.

As a result, more and more designers and builders are taking matters into their own hands and are increasingly searching for ways to protect properties against the devastating effects of Mother Nature. The most advisable course of action seems to be to build in flood protection from the offset when designing or building a property, with the use of devices such as door guards, airbrick covers, valves and pumps to protect the properties by making them more resistant to flooding, particularly where economic restraints rule out a traditional scheme using floodwalls or embankments.

In particular, backflow valves are playing a crucial role in providing protection to vulnerable properties. These high performance systems are becoming increasingly critical in the fight against flooding, especially when you consider that statistics from the Environment Agency estimate that 80% of all UK buildings are at risk from backflow flooding at times of heavy rainfall, regardless of their location.

Equally, these anti-flood systems can protect against one of the more serious implications of backflow flooding - contamination. On average, there are more than 10,000 reported cases of backflow contamination each year, where pathogens and microorganisms present in water have caused infections in human beings after being ingested or inhaled or coming into contact with an open wound. To give you some idea of how serious this can be to an individual's health, we should consider some of the types of pathogens that can be found in sewerage water, which include bacillary dysentery, pneumonia, botulism, hepatitis A, meningitis and septicaemia, to name just a few.

Leading manufacturers are developing ever innovative backflow valve technologies to provide unrivalled protection against flooding and its associated effects. For example, the latest series of automated anti-flood systems from ACO Building Drainage have been designed to provide extremely reliable operation over long service lives in both grey and black water applications and in a range of new build or refurbishment projects for both commercial and residential properties.

These high performance units incorporate a pressure sensor located in the valve body. This works in conjunction with a high torque DC motor that controls a motorised flap, which automatically closes against a watertight seal whenever a backflow from the sewer exists. The motor then automatically reopens the watertight flap once the backflow from the sewer abates. These devices ensure reliable operation in even the most polluted black water conditions and also feature a secondary flap with manual override that can be closed during construction or refurbishment programmes to prevent odours entering the building or to act as a failsafe should the first flap fail.

Perhaps most importantly, these new products are designed, manufactured and tested in accordance to BS EN 13564, and can be installed simply in the discharge pipes from premises, to prevent flooding that might be caused by excessive storm water or pumping station failures resulting in a high backflow from the main sewer system.

The backflow valves are also rated at IP67, meaning that the motor and valve body can be used safely in locations that are susceptible to storm water flooding, as all electrical connections are fully sealed against the ingress of moisture or other contaminants. There is also the option of a separate IP56 rated remote control box, which is ideal for use in basements, utility rooms and plant room locations to provide a visual and audible indication of backflow and valve status at all times, while a battery back-up facility ensures reliable operation for 24 hours until mains power is restored, in the event of mains power failure.

Combined with the use of these devices, there are a number of things that property owners can do to improve the flood resistance of their home or business still further, by looking at other parts of the buildings drainage system which could become a source of water ingress, such as toilets, baths and basins, as well as washing machines and dishwasher outlets. It is also important to remember that even manhole covers close to a property can lift up due to backflow during flooding so these also need to be considered.

The following is a practical checklist that gives details of the measures that can be taken to prevent water backing up into your property.

Considering that the costs of dealing with floods can easily run into billions, the case for flood protection systems is particularly strong, especially considering that the Environment Agency estimates that the annual cost of damage to residential and commercial property from flooding in England could rise from £2.5 billion to £4 billion by 2035 if no defences are put into place. Indeed, the modest expense of installing backflow valves seems extremely insignificant compared to the damage and devastation that can be caused by flooding if they are not fitted, making them a pragmatic and highly effective solution to quell this threat in years to come.