Storm disruption

Wellington boots in flooded water

Tom Francis, Utilities Scientific Consultant at the Met Office, comments on the impact of recent storms for the water industry.

As some of the highest energy users in the UK, water companies have been impacted considerably by interruptions to the power network brought about by fallen power lines during the recent stormy weather, high winds and prolonged periods of heavy rainfall.

Over the last few weeks, interruptions to the electricity supply have threatened the treatment and distribution of water as control room technology, pumps and alarms have been disrupted by intermittent and sustained blackouts.

The greatest challenges were felt at sites where back-up generators failed or were not available, requiring mobile generators to be deployed. The fuel required for running mobile units, and the unplanned overtime for staff to install and maintain them, has cost the industry - exacerbated by the Christmas and New Year holiday period.

Kent and Sussex were particularly badly hit, with South East Water needing to deploy staff around the clock over the Christmas period to restore water supplies to customers. Interruptions to electricity supplies caused by lightning strikes, flooding and wind damage, meant generators needed to be put to use across the region and emergency maintenance carried out at pumping stations 'knocked out' by the disruption to power.

In total, over 70 technicians, customer service staff and contractors cancelled their Christmas holidays and worked long hours throughout Christmas Eve and Christmas Day to restore water supplies.

Paul Seeley, South East Water Operations Director, said: "The storm caused numerous power cuts across our supply area which left many areas without water.

"We worked 24 hours a day throughout the Christmas period to restore supplies by attaching generators to the water treatment works, pumping stations and reservoirs affected.

"Working closely with our Local Resilience Forum meant we were regularly getting the latest Met Office and Environment Agency updates which helped us plan our activities and ensure we were able to get customers' water back on as quickly as possible while also keeping our staff safe too."

Similarly, Welsh Water responded effectively to power interruptions at seven Water Treatment Works in the New Year when severe weather returned. At Amroth, on the south west coast, an unexpected combination of high tides and strong winds washed away a section of road along the sea front, severing a water main in the process. Technicians were swiftly deployed and repaired the water main to ensure supply interruptions were kept to a minimum, despite the difficult conditions.

On the wastewater side, the heavy, persistent rainfall across much of the UK caused many rivers to burst their banks, threatening nearby wastewater treatment works. High river levels often prevent treated wastewater from being discharged at the works and sewer overflows which can lead to sewage backing up in the network.

Water Utilities will no doubt be counting the cost of the recent stormy weather and will inevitably have to review whether investment to protect assets is required to mitigate the impact of such weather in the future.

With relatively mild temperatures to date, others may also be wondering whether a sudden drop in temperatures is imminent and what the implications may be for leakage and bursts.

Last updated: 10 February 2014