With the Environment Agency holding a Flood Action Week in November 2021 and the Met Office predicting an above average likelihood of a wet winter this year, regular flooding looks set to become a reality for many UK regions.

Will Lang, Head of Civil Contingencies at the Met Office said, “Winters in the UK usually include a wide variety of weather and this winter looks to be no exception. However, when looking at the big global drivers that impact weather in the UK there are indications this winter could be wetter than normal.”

Whether you are a private resident, a construction company or developer, flood risk is a new reality that everyone needs to consider.

At Premier Drainage Solutions, we’re used to thinking about flooding and drainage strategy but it’s clear that things are changing fast, and flood risk and resilience needs to be high on everyone’s agendas.

What is the impact of flood risk on commercial build developments?

New-build developments now consider including flood defences such as integral sumps and pumps, or even community flood kits on development sites. All developments need to use sustainable urban drainage schemes (SUDS) and permeable paving. They also carry the responsibility for maintaining these systems.

We might also see policy shifts to address flood risks over the coming months, such as stricter legislation on planning and building new developments in flood risk areas, an effort to increase wetland or woodland cover, and the possibility of returning some rivers to their natural courses. These proposed solutions are long-term, large-scale options that will play out over the years to come.

Martin Milliner, Claims Director at LV= General Insurance, said, “Climate change will increase the UK’s exposure to weather-related hazards such as flooding, and it’s vital we prepare for this.”

How can we consider flood management on build sites?

A drainage strategy must be in place and designed by a competent person (drainage engineer) on all sites big and small in order to eliminate flooding issues. Most sites will now have an attenuation tank (figure 1 and 2) on site. This means before the water leaves the site, it can be stored within the site tank and released at 5 litres per second (dependant on site conditions) therefore, it won’t overload the sewers as it leaves the site and offers some form of control.

What are the different effects of flood risk in terms of residential or commercial clients?  

Premier Drainage Solutions serve a number of clients in different London areas who have been heavily affected due to their position under the set elevation.  It’s becoming more and more common to see basement floods in the London area and whilst commercial clients usually have this covered – often with big depots and plenty of surface area to install the attenuation tank below the hard surfacing – smaller developments or residential sites find it harder to cope.

What is Premier Drainage doing differently?

When we work with a smaller building developer and the time arrives to pass the project on to a drainage engineer, we would now ask for at least 20% more storage than we would previously have recommended to be factored in as a safety precaution. The engineer would advise us and the development on this but planning ahead for future flood risk is certainly a live issue at the moment and we recommend factoring this with future planning whenever possible.

What advice do you have for residential users?

As The Environment Agency said this week, the best thing you can do is check your flood risk online, sign up for flood warnings and, if you think you live in an area that is at risk – make sure you know what to do if flooding hits. Apart from preparing for large flooding, you can also take some action against smaller flood risks at home by making sure that your drainage system is free from blockages and running well.

Flood risk is an issue that looks as if it is here to stay. Information for developers and contractors about flood resilience can be found here on the UK.GOV website. Residential clients can find out more about how to prepare for flood risk with the National Flood Forum here.

Premier Drainage Solutions has over 40 years’ experience in drainage and sewer planning, maintenance and installation, if you’d like to ask our advice about your drainage system, contact us here.