A permeable paving slab that can absorb excess rainwater and mitigate flooding risk is one of 20 projects in the running to win a portion of the £4 million made available in Ofwat’s latest innovation competition.

Ofwat’s Innovation Fund has today announced 20 finalists for the Water Discovery Challenge, a competition to reward innovators from outside the water sector with solutions that can tackle its biggest challenges and benefit customers, society, and the environment.

A next-generation permeable pavement that allows rainwater to be absorbed by the ground beneath could soon be trialled across the UK in an effort to combat flooding through water-smart cities.

Government advisers have found that 325,000 homes and businesses are at high risk of floods when intense rainfall overwhelms drains, a problem exacerbated by concrete surfaces in cities.

Kiacrete, developed by a team from Imperial College London, uses an advanced material consisting of concrete with a bespoke plastic drainage structure to efficiently drain stormwater. The gradual release means that the ground beneath the slabs don’t become overwhelmed and water-logged.

Kiacrete could lead to significant environmental improvements, reduced risk of sewage overflows (which occur after heavy rainfall), a more resilient and sustainable water sector, and lower customer bills.

A filtration device that enables roadside drains to catch particulate pollution is also amongst the finalists. The technology captures pollution that would otherwise be washed into the ocean following heavy rainfall in cities. The system, from Guerilla Technologies, will capture particulate matter – containing microscopic solids or liquid droplets that are so small they can be inhaled and cause serious health problems.

Alalea Kia, Project Lead for Kiacrete and UKRI Future Leaders Fellow at Imperial College London, said:

“Cities face an increasing challenge from floods due to the impermeability of urban surfaces such as roads, pavements and garden patios, meanwhile extreme weather events such as heavy storms are increasing in frequency due to climate change.

“Our permeable paving solution will increase cities’ resilience to heavy flooding, improving conditions for adjacent industries including transport and other utilities, and ultimately future-proofing our urban areas by turning them into water-smart cities.”

David Black, CEO, Ofwat said:

“It’s no secret the water sector is facing tough challenges, and difficult choices, related to climate change, the wider environment, and society. As the regulator, it’s our responsibility to help the sector to find new ways to overcome these pressing challenges.

“Water affects all industries, so with the Water Discovery Challenge we wanted to cast our net outside the sector, and see what those in adjacent industries propose to help us maintain a safe and sustainable supply. The finalist ideas address numerous core concerns for the future of the sector – from future-proofing cities to anticipating the impact of climate change, and we’re excited to help bring these ideas to life.”

The 20 finalists will now be awarded up to £50,000 from the Ofwat Innovation Fund, as well as non-financial, capacity-building support, to develop their ideas further, along with expert support and mentoring from water companies. Up to 10 will go on to win up to £450,000, as well as further support, to further develop and test their ideas, including delivering pilots.

Other solutions range from hydropower turbines which can harvest electricity from water flowing through pipes, to a new membrane which could enable energy-efficient desalination, and a novel ‘spray-on’ pipe liner to repair leaks.

The Water Discovery Challenge is part of a series of competitions from Ofwat run by Challenge Works with Arup and Isle Utilities, designed to drive innovation and collaboration to benefit customers, society and the environment.

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