UTILITY SITES FLOOD PROTECTION

The floods of 2007 highlighted the vulnerability of the UK’s critical infrastructure, when the Mythe Water treatment works was cut off by rising floodwaters and water supply to 350,000 people was cut off for up to 11 days, and the Walham electricity substation was effected with 42,000 people losing power for up to 24 hours.

Following on from this event a number of reviews and reports highlighted the need to protect the UK’s critical infrastructure from flooding, and numerous programmes of work were commissioned which are planned to continue until 2020 and beyond.

Flood Control International is fully involved in delivering these flood mitigation programmes and is working with the majority of utility companies in the UK to provide solutions. We have been providing flood protection to these sites since 2003, when our first programme of 26 electricity substations commenced. We have now delivered over 60 utility flood protection projects for water, power distribution and power generation companies, and the list is growing.

 

Specific Issues for Utility Sites

Utility Sites have specific issues associated with their protection:

• They are often remote and unmanned
• They are visited by a variety of personnel, and
• They must be secure.

The number of sites, and their remote locations mean that they generally need to be left ‘floodsafe’, as there may be insufficient time to check or install flood defences once a flood alert is issued. There are two main solution types; the first is to surround the entire perimeter with a concrete flood wall incorporating gates or floodbarriers. Where this is not possible, the second type of solution is to create protection at the building line itself.

 

Concrete Wall and Flood Gates

Where perimeter concrete walls are chosen, our unique Lift-Hinged floodgates are used for vehicle accesses up to 4.5m wide. These gates are chosen as they can operate over a level threshold and do not need steps or ramps to close against. Most sites need wider accesses infrequently for transformer or large plant deliveries, and so we developed a way to integrate lift hinged gates with other gates using demountable centre posts, or demountable barrier runs making openings as wide as they needed to be.

Our gates are normally of aluminium and stainless steel construction, giving ease of use, minimal maintenance requirement and dependability.

Where there is no room to swing a floodgate, we have designed floodbarriers that pivot upwards out of the way, for easy one person operation to deploy rapidly should the need occur. Smaller pedestrian gates are used where steps are allowed at thresholds. Our standard solutions here are suitable for flood depths of 1.6m, although we have designed and supplied flood gates and flood barriers for flood depths of up to 4.5m where required.

 

Protection at Building Line

Many utility sites do not have the space to incorporate a perimeter concrete wall. In these instances, protecting the building line with tanking and duct sealing is often specified. As the condition of existing buildings, the number of cable/service entries and condition of any foundations are often unknown, sump pumps are normally provided to discharge any floodwater that does seep into buildings to keep levels down during a sustained flood event. Infrequently used openings are protected with demountable barriers which can be fully removed when required. Where regular access is required, our steel Flood Security Doors are specified.

Security Flood Doors

Our secure Flood Doors are watertight to full depth due to a unique sealing system and can be specified as 60 minute fire doors. Flood Doors come with the full range of furniture options including windows, emergency escape bars and security rated fittings. The flood doors are watertight when closed, and are usually specified as always requiring key access from the outside. These features give our clients confidence that whoever has visited each site, that it will be left secure and flood-proof.

In addition to protecting simple openings, we have installed complete barrier surrounds around plant items or to hatches below flood level allowing continued access in time of flood, and have linked some barriers to a building management system to identify when barriers are in place.

 

Increased Risks Require Solutions Now

DEFRA’s recently published Climate Change Risk Assessment states that ‘The risks of flooding are projected to increase significantly across the UK in the coming years’. With increasing numbers of assets at risk, and increased flood protection requirements, our expertise in delivering the right solution for utility sites looks set to continue for many years to come.