Working on behalf of the Environment Agency, Team Van Oord has successfully completed an innovative scheme to provide improved protection from flooding to households, infrastructure, agricultural land and an area of outstanding natural beauty within the Severn Estuary.
The scheme at Stolford features the deployment of block revetments, as developed in the Netherlands, instead of the conventional rock revetment approach – to provide an affordable solution to a long-term problem.
The scheme was carried out by a team from Kier and the Dutch based designers RHDHV, working as part of Team Van Oord. Work began in November and the project was complete before the end of 2018.
Using their extensive knowledge and links to the Netherlands, Team Van Oord identified the Hillblock block flood protection system – new to the UK but extensively tried and tested in the Netherlands – as the most cost-effective and appropriate option.
Jaap Flikweert, Leading Professional Resilience with Team Van Oord partner Royal HaskoningDHV , said: “ This first use of Hillblock in the UK represents a new standard in coastal protection – providing stronger revetments at lower cost. We firmly believe there is a good chance that block revetments can be a competitive option for many other coastal defense projects in the UK and worldwide. ”
Hillblock is an innovative revetment block that varies in size from 200 mm up to 700 mm. Due to the shape and configuration of the voids, when placed together there is a significant reduction in the impact of energy from waves and wave run-up of up to 30%, compared to other types of shore protection.
As the wave hits the Hillblock system, the water penetrates the voids between the blocks. These voids provide an enlarged flow area; this reduces the wave run-up by increasing friction and the pressure needed to squeeze the water through the channels.
The project received some funding from the Dutch Government’s ‘Partners for Water’ program, which supports the use of Dutch water management innovations worldwide – with the aim of improving global resilience while supporting Dutch businesses.