Flooding in Gloucestershire
July 2007

During the devastating 2007 summer floods Hesco Bastion Ltd was called in to protect three key critical infrastructure sites on the River Severn flood plain in Gloucestershire. Working together with local contractors and the Armed Forces, the experts from Hesco deployed two kilometres of flood defence barriers around these sites to protect them from the threat of further flooding.


Walham Switching Station

In late July 2007, news broadcasts during the floods pictured Walham Switching Station perilously close to being inundated by flood water and thereby risking a loss of power to the 500,000 residents it provides with electricity. 

The emergency services battled with pumps and temporary flood defences to protect the site and on Tuesday 24 July, National Grid decided to place an order with Hesco Bastion Ltd to provide more robust protection to this key facility. 

The Hesco Concertainer® units arrived on site at 0800 on Wednesday 25 July and work began on Friday 27 July.  A second flood warning meant that it was a race against the clock to protect the site as soon as possible and avert a potential disaster.  Fortunately the Hesco system is designed specifically for rapid deployment under these conditions.

In just 19 hours a 1.37m high barrier was erected, stretching for approximately 700 meters around the site and filled with 1800 tonnes of crushed rock aggregate. 

The Royal Airforce and Royal Engineers, under Captain Christian Hulme, worked alongside the team from Hesco to protect Walham with a secure defence wall, ensuring that the power remained on for local residents.

Mythe Water Treatment Works

On the 21 July 2007, Mythe Water Treatment Works was flooded resulting in the site being out of service for a week and leaving an estimated 150 000 residents without running water. 

Once the flood waters had subsided, the engineers at Severn Trent were able to gradually restore the treatment works to working order and a limited distribution of non-potable water was reinstated.  It was at this point that another flood warning for the area was issued and waters threatened to flood Mythe for a second time in as many weeks, sending Severn Trent back to square one and depriving local residents of water for even longer. 

At 1500 on Friday 27 July, following a decision by COBRA, Hesco Bastion Ltd was contacted to provide flood defences using the patented Concertainer® unit.  After Hesco has completed a site survey, the units were despatched immediately from Hesco’s Leeds factory and arrived on site at 2130.  Planning continued throughout the evening and work began the following morning at 0700.  Under the expert guidance of the team from Hesco, the Armed Forces and contractors from Interserve began to construct what is now a perimeter barrier of flood defences stretching for just under a kilometre in length and standing 1.37m high.  The teams worked using excavators, loaders and wheelbarrows to fill the units with 2400 tonnes of crushed rock aggregate, which had been delivered by a fleet of tipper trucks.  In just 27 hours, the wall was complete, protecting the site from the risk of flooding before the rains came again.        

Castle Meads Substation

After the success of the projects at Mythe and Walham, Central Networks decided to deploy Hesco’s flood defences at the nearby Castle Meads substation, which supplies electricity to 48,00 homes. The site, built 50 years ago, lies right on the flood plain, surrounded on both sides by the River Severn.  Until this summer Castle Meads had never before seen flooding on this scale.

The substation was flooded on 22 July and taken offline for a short while as a result. Temporary flood defences had been put in place, but once the waters subsided, Central Networks decided to install a more permanent solution to protect the site from the risk of further flooding.

Following the example of other local utility companies, Central Networks contacted Hesco Bastion Ltd to provide 300 meters of Concertainer units to protect the site. 

A site survey was conducted on 26 July and on the 2 August, under the guidance of the Hesco team, contractors Enterprise Power Services began work to construct the walls by filling the units with a semi-dry concrete mix to form a strong perimeter barrier around the substation. The barrier is now complete and provides a long term solution to the flood risk at this key facility.