Flood defences expanded in Seven Kings, Clayhall and Barkingside

Flood defences have been expanded in Seven Kings, Clayhall and Barkingside, where new underground Hydrorock systems are designed to reduce the risk of roads and homes being affected by heavy rain. The works form part of a wider £11 million plan by an east London council.

The sites — High Road in Seven Kings, Claybury Broadway in Clayhall and Tomswood Hill in Barkingside — were identified as potential flood risks after previous flooding. The schemes installed this year can temporarily hold around 426,000 litres of storm water; the borough’s wider defence network has capacity for 2.2 million litres.

How the new defences work

Hydrorock acts like an underground sponge. It absorbs rainwater during heavy downpours, stores it temporarily and then releases it gradually into the sewer network. The aim is to prevent sudden surges of water overwhelming sewers and flooding roads.

Sections of road were also resurfaced with permeable paving, allowing rainwater to drain from the surface into the Hydrorock blocks. The system was developed in the Netherlands. Councillor Jo Blackman, the council’s cabinet member for environment, said the town hall was “strengthening our flood defences, reducing local flood risk and helping build resilience” as “extreme weather becomes more common”.

What is planned next

The latest installations follow six rain gardens added in Clayhall, Woodford and Hainault earlier this year. A timetable for further flood defence works has not been announced.

The expansion comes after a summer of record-breaking heatwaves in London. Scientists and forecasters are warning that an El Niño on a scale never seen before could make extreme weather more likely over Britain this winter. The account of the scheme does not specify how the new defences would perform in any particular storm.

This report draws on information from Yahoo News UK and The Standard.