Marshalls Priora used on a new housing estate in Sheffield

How can we protect new homes from flooding?

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Monday 23rd May, 2022
With the UK government's pledge to build 300,000 new homes each year, there is increasing pressure on housebuilders to develop in flood risk zones. 

Between 2015 and 2021, 56% of new dwellings were built in neighbourhoods where some flood risk exists. In 2019, the Environment Agency reported that 5.2 million homes (as many as one in six properties) were at risk of flooding in England.

In addition to this, a recent report by the Environment Agency predicts there could be up to a 50% increase in the number of houses built on flood plains over the next 50 years. And as more developments are built on flood risk land, housebuilders, designers, and local authorities are presented with a number of challenges.

Marshalls has worked with Housebuilder & Developer Magazine to gather further insight on this subject. We interviewed over 100 housebuilders, contractors and clients to understand their views on the perceived importance of future-proofing for flood risk. A link to download the whitepaper on this topic is at the bottom of this article.

The effects of flooding 

The impact of flooding has a lasting effect on both individuals and communities, as well as social, economic, and environmental consequences. In light of the government's pledge to new homes, building on land at risk of flooding seems inevitable, however there are a number of ways that we can negate the impact and reduce risk.

When asked, 61% of participants agreed that the UK government's pledge to build more homes directly impacts the amount of flood risk land being developed. As a result of this, 81% believe that the government should commit more money towards flood protection.

Offsetting the impact

Use of flood protection products in the UK

The research shows that, while the industry continues to progress towards the adoption of Sustainable Drainage Systems (SuDS), more than 20% of respondents still rarely factor them into their schemes. The use of both hard and soft SuDS and traditional drainage systems offer a long-term sustainable approach to flood risk mitigation, targeting surface water runoff.

But, whilst the above figure is concerning, 79% of interviewees stated they had become more aware of flood risk management in recent years, and 42% now always adopt SuDS as standard in their projects. 38% install SuDS in projects occasionally, 6% rarely do so, and 15% never do so at all. 

Even if they’re not installing SuDS, 75% believe that all developments should incorporate them. At present only 'major developments' are explicitly required to add them.

What is clear from the white paper is that there is an urgent requirement for water management solutions that answer the need for security against flooding - whether they be above ground, such as permeable paving and flood walls, or below ground drainage solutions that hold, control and release flood water when appropriate.

When asked what flood protection products respondents have used and would consider using in the future, permeable paving was the most commonly cited, with 58% of respondents having already used it, and 53% considering doing so.

Used widely, permeable paving is a pavement with a base and sub-base that allows water to infiltrate or pass through the surface. This helps to reduce surface runoff, as well as effectively trapping any pollutants and solid particles in the water, avoiding ground water pollution.

Barriers and contributing factors

Barriers to using SuDS in the UK

When prompted about barriers to introducing SuDS, cost was the most common issue, cited by 55%. The other key challenges related to uncertainty around the subject, in particular a lack of understanding about the systems, confusion about who is responsible for specifying and the absence of enforced regulations.

Despite the widespread recognition of Sustainable Drainage Systems' value, there continues to be some confusion over who is ultimately responsible for the maintenance of SuDS. Only 43% of people felt that the 'Sewers for Adoption' guidance clarified this.

When prompted about who should be responsible, 41% felt the accountability lay with builders and developers, 45% with owners, and 61% councils.

Most participants felt there is not enough engagement between decision-makers, with just 29% confidently stating that they felt that there was the right level of collaboration between Government, Developers, Councils & Planners.

And, coming back to maintenance, the old myth still remains that permeable paving gets clogged up quickly and requires more maintenance than other options. Recent field tests to evaluate the performance of concrete block permeable pavements discredit this, but the message needs to be more widely understood.

Take action to future-proof new build homes

With more new homes built on flood plains as we see increased flooding due to climate change, implementing different measures to help with flooding and water runoff must be a priority.

At Marshalls, we believe in using the most ethically sourced materials; we operate as sustainably and as socially responsibly as possible. This is the commitment we make to our customers, partners, stakeholders, and the communities where we do business.

We recognise that creating the best solutions and providing robust and proven products for sustainable water management is how we demonstrate this commitment, reducing the strain on local drainage systems and helping to future proof against flooding.

For more information on this topic, download the Future-Proofing Against the Risk of Floods whitepaper or sign-up for a free Marshalls CPD on Creating Climate Resilient Spaces or SuDS and permeable paving solutions. For further expertise and support, the Marshalls Design Team are on hand to offer advice, guidance and designs for Marshalls customers.

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