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Latest floods trigger defence cash calls

Network Rail and flood defence experts this week united to call for more government cash to protect vital infrastructure networks from the effects of climate change.

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Fighting the floods: Network Rail teams used inflatable barriers to prevent water damaging key junctions

The call follows a month of widespread heavy rain and flooding that badly disrupted transport infrastructure. For the first time, Network Rail has asked the government to approve spending specifically aimed at addressing the impacts of climate change on key rail assets.

In its strategic business plan for 2014 to 2019, published this week, the organisation has asked for cash to future-proof the network against climate change impacts, including flooding.

“We are well aware of the challenges that climate change poses,” a Network Rail spokesman told NCE. “We need to start ratcheting up how we deal with it. Extremes are becoming more normal - like the flooding we have just seen. This is something we know we need to prepare better for,” he added.

The West Country was badly hit over Christmas, with several routes blocked for a number of days. Network Rail engineers even resorted to using inflatable dams to protect signalling and key junctions.

Part of the extra funding would be spent on assessing and monitoring 30,000 key structures on the UK rail network, before carrying out enhancements to protect them from the increased risk of climate change impacts like flooding and higher winds.

The request for extra funds forms part of Network Rail’s business case for Control Period 5, which runs from April 2014 to March 2019.

The Office of the Rail Regulator will give its initial response to the business plan in June, and will publish its final determination in October 2013.

Experts agreed that key infrastructure must be made more resilient to floods, adding that the current flooding could last for months and that flash floods may become the norm in future years.

“We need to look more at the resilience of structures so they can recover better,” said Association of Drainage Engineers chief executive Jean Venables.

“An awful lot of infrastructure is impacted - the recent damage to railways and roads shows that.”

WSP head of water engineering Ola Holmstrom also warned that key infrastructure could be at risk as weather patterns are changing.

“We are heading towards a time where there will no longer be any real drought or rain periods, we could just as easily have a drought winter and a flood summer,” he said, adding that adapting to these new weather patterns requires “innovative thinking”.

“Our core infrastructure will need to be adapted, reinforced and in some cases completely rebuilt, which comes with a cost,” Holmstrom said.

Christmas disruption

More than 800 Environment Agency staff worked over the festive period to reduce the risk of flooding across England and Wales.

Staff worked to shore up defences, clear blockages from watercourses, monitor river levels and install temporary flood defences to protect properties from flooding. Areas affected included at Ironbridge, Bewdley, Shrewsbury and Oxford.

Latest figures show that around 540 properties had flooded since Wednesday 19 December. The Environment Agency has sent over 115,000 warnings to people at risk of flooding. Flood defences have protected thousands of properties across England and Wales.

“Over 21,000 properties have been protected from flooding this Christmas and our teams are continuing to work around the clock with local emergency services to keep communities safe,” said Environment Agency flood risk manager Pete Fox. “The recent rain has left river and groundwater levels high and people should continue to keep up to date with the latest flooding updates,” he added.

As NCE went to press 12 flood warnings remained in place.

 

He added that in future the UK will see an increase in total rainfall, and more frequent, short bursts of intense rainfall, which will result in flash flooding.

He said most flood defences should be able to cope with this change, as they are designed for major flooding events. However, it will have a major impact on smaller catchments and in urban areas, where it is “almost impossible” to build defences.

“The only options are to improve resilience or divide your catchments up and create bypasses so the water doesn’t develop momentum and collect in one location,” said Holmstrom, who suggested that more “resting places” should be created in urban areas in the form of mini reservoirs where water can pond safely.

The recent floods have involved river, surface water and groundwater flooding. Venables warned that any rainfall between now and Easter will cause more flooding, as catchments are saturated.

“It is as if the rain is falling on an impermeable surface, because there is no storage, so it runs straight off,” she explained.

“Aquifers are full to overflowing, and raised groundwater is causing groundwater flooding in a lot of areas.”

Venables said that a dry period would need to go on “for weeks” to allow current water levels to subside. She added that more needed to be done to ensure existing drainage channels are maintained, and slammed proposed cuts in the Environment Agency’s maintenance budget over the next three years.

“Although they have been given extra money for new capital works, the amount of money for existing defences is declining,” said Venables.

“The capital funding is welcome to those communities that are going to benefit from it, but it is skewing the building of new defences at the cost of maintaining the existing,” she added.

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