The severe flooding at Walham, Gloucestershire in 2007 made UK Power Network realise the possibility of using temporary flood barriers for their flood protection. Rising floodwaters surrounded a National Grid switching station, but the swift deployment of the Geodesign barrier prevented a potential disaster. Together with effective pumps, the barrier stopped the rising water from entering the switching rooms through underground cable ducts and ensured 600,000 people kept their electricity.
John Gibbs, Contingency Planning Manager at UK Power Network, explained the company's emergency preparations:
"We subscribe to the Environment Agency Flood Warning Direct System, which sends us an email about a substation at risk. We then liaise with the flood Information duty officer in the Environment Agency, who informs us of the substations of highest concern."
Bill Blackburn, Area Manager for Sussex at UK Power Networks, highlighted the practicality and efficiency of the system:
"At a severe flood warning, we would start to make preparations to erect the barrier. It would probably take about three to four hours to protect a large site like this. A significant consideration is how much notice we have, determining if we have ample time to secure the whole site or if we should primarily focus on the most vulnerable parts."
The Geodesign barrier distinguishes itself from traditional methods. Whereas traditional means would require the transport of tons of sand to construct a barrier to a dam height of 1.25 meters, a Geodesign barrier is a lot quicker. Comprising galvanised steel supports, horisontal connection rods, and aluminium sheets, the Geodesign temporary barrier system can be ready within a few hours. This ease of deployment is especially vital given the flood risks inherent to many of the company's 300 primary substations, including those situated in areas like Hartfordshire, known for their flood vulnerability.
Upon erection, the barrier is draped with a polypropylene sheet, serving as a protective, waterproof membrane. This sheet, held down by chains and clips, effectively seals against potential water seepage.
The effectiveness of the Geodesign flood barrier system was on display during a December storm surge in North Norfolk. Though the predicted floodwaters at the Great Yarmouth substation never materialised, the Geodesign barrier's readiness ensured optimal security.
During flood emergencies, UK Power Networks work together with the Environment Agency and other governmental bodies, including the police and fire brigade. Dedicated to its 8 million customers across East Anglia, London, and the Southeast, the company stresses the need for advance flood preparations. If flooding threatens a property, property owners are advised to switch off electricity at the mains (if safe) and to reach out to UK Power Networks via their dedicated emergency channels or their official website.
