Select Committee on Environment, Food and Rural Affairs Minutes of Evidence

Memorandum submitted by Severn Trent Water Limited (FL 69)

  The extent of the recent flooding in Gloucestershire was unprecedented. Although, we have the normal contingency and business resilience planning, Severn Trent needed to use its full resources to deliver an appropriate emergency response.

  The incident raises key issues for the national water infrastructure and the capacity of any one organisation to respond effectively to an event of this scale. We welcome the debate which, in our view, will need to consider how best to organise for an integrated response to these types of events.

  We have described the incident response in some detail in our submission and look forward to providing additional commentary in October. If there are matters which we can usefully progress in the interim, we would be delighted to hear from you.

  Our submission is drawn wholly from an initial Interim Report that we have prepared for the many external parties that have an interest in how we handled the incident. We do anticipate that this separate document will be in the public domain shortly.

Tony Wray

Managing Director

Severn Trent Water Limited

August 2007


  1.1.  Severn Trent Water Limited (STW) is a wholly owned subsidiary of Severn Trent Plc, a public limited company listed on the London Stock Exchange and registered in England and Wales.

  1.2.  STW is a water and sewerage undertaker serving over 3.7 million households and business customers in England and Wales. Our region stretches from Mid-Wales to Rutland and from the Bristol Channel to the Humber. We deliver nearly 2 billion litres of water per day to homes and businesses through 46,000 km of pipes, a further 54,000 km of sewers take waste water away to over 1,000 sewage works.


  2.1.  The Gloucestershire flooding in July 2007 was a civil emergency involving major disruption to the transportation and utilities infrastructure of the region. The response was coordinated under the Civil Contingencies Act 2004 framework, led at regional level by the Chief Constable of Gloucestershire Police in his capacity as Gold Commander.

  2.2.  On Saturday 21 July, as river levels started to rise, our flood response procedures were activated. Additional pumps were obtained, key buildings were sandbagged and plans were put in place for partial power shut off in designated areas. Early on Sunday 22 July, the Mythe Water Treatment Works (WTW) was shut down under carefully controlled conditions due to river flooding. A timeline of how the incident developed and the mobilisation of response and recovery is set out in the appendix.

  2.3.  By Tuesday 24 July, there were approximately 140,000 properties without a piped water supply. Supplies were restored on a phased basis with all customers reconnected to piped water by Thursday 2 August and all water was declared safe to drink on Tuesday 7 August.

  2.4.  In the meantime, customers were provided with alternative supplies through use of bottles, bowsers and tankers. We deployed in excess of 1,400 water bowsers, the largest number ever used in a single incident in the UK, and delivered up to 5 million litres of bottled water per day. Up to 1,800 of our employees, together with suppliers and other agencies, worked around the clock in response to the incident.

  2.5.  In recognition of the impact of the incident on our customers, we have allocated a fund of £3.5 million to benefit the affected communities and are working with key stakeholders to determine how these funds will be used. We believe that a contribution such as this will be of long term benefit to all in the community.

  2.6.  The flooding in Gloucester has raised three broad questions for our business: first, the adequacy of flood defences; second, the extent of "redundancy" such that the failure of a key asset can be compensated by other means without interruption of service; and third, the adequacy of contingency planning should supplies fail.

  2.7.  We are undertaking a process to review the detailed lessons learned from the flooding incident and will produce a full and final report in due course. We are paying close attention to the feedback from our customers and are holding a series of customer road shows during September.


  3.1.  The Mythe WTW is built on artificially raised ground on the bank of the River Severn close to the confluence with the River Avon. Here, water is extracted from the river for treatment and onward supply into the network. Operation of the Mythe WTW had not previously been lost due to flooding, although owing to its proximity to the rivers Severn and Avon the risk had been recognised. This was particularly highlighted during local flooding in 2000. Flood defences consisting of a land drainage system and pumping facilities were already in place and in operation at the site prior to the incident. We believed these defences were adequate given the history of the site.

  3.2.  July's unprecedented rainfall in an already saturated area resulted in serious river flooding in parts of the Severn and Avon valleys, with floodwaters inundating the Mythe WTW on Sunday 22 July 2007. This resulted in the loss of piped water supply to approximately 140,000 properties in the Tewkesbury and Gloucester area.


  4.1.  During the week preceding the floods, the Environment Agency issued a number of general advance warnings of flooding. However, these warnings provided no indication of the full extent of the flooding. On Friday 20 July, we issued an emergency weather warning to all works managers. This triggered the normal operational response to increase standby resources and secure chemical treatment stocks.

  4.2.  During Saturday 21 July we communicated regularly with the Environment Agency who predicted that the river would peak at a level that would not inundate the works. As the river levels continued to increase, we invoked our Flood Emergency Response procedures for Mythe WTW. Additional pumps were obtained, key buildings were sandbagged and plans were put in place for partial power shut off in designated areas. By midnight the Environment Agency confirmed that flooding was inevitable.

  4.3.  Late on Saturday 21 July, as a precautionary measure we switched some areas to an alternative source of water from Mitcheldean WTW, maintaining supplies for approximately 20,000 properties throughout the incident.

  4.4.  We established an incident management team early on Sunday 22 July, comprising teams responsible for handling alternative supplies, recommisioning of Mythe WTW, restoration of water into distribution and managing the impact on sewerage infrastructure. In recognition of the likely prolonged nature and scale of the incident, we reorganised our command structure on Wednesday 26 July under the control of our Managing Director.

  4.5.  On Sunday 22 July we integrated into Gold Command at the Police Headquarters in Gloucester. We had permanent staffing at Gold Command in Gloucester throughout the remainder of the incident.

  4.6.  At the time the Mythe WTW was shut down the service reservoirs were approximately 75% full, which is equivalent to approximately 36 hours supply of water in normal circumstances. However, following the first news broadcast at around 0900 hrs warning of imminent loss of supplies, water usage more than quadrupled, resulting in a more rapid depletion of supplies.

  4.7.  The first actual cessation of flow occurred at 1800 hrs on Sunday 22 July. By Monday 23 July, there were 70,000 properties without a piped water supply. This increased to approximately 140,000 properties by Tuesday 24 July.

  4.8.  Our primary objective after Mythe WTW had to be shut down was to ensure sufficiency of water supplies for sanitation and health. As established by our emergency procedures, customers with special needs, such as hospitals, prisons, major commercial customers and individual domestic customers, such as dialysis patients, were contacted to confirm specific supply arrangements in each case. These were maintained throughout the incident.

  4.9.  A key priority was to maintain water levels in the service reservoirs so as to prolong piped water supplies to the area. This was achieved using tankers to transport water from Strensham WTW. In addition, we reviewed the potential to re-route water from other sources and by Friday 27 July 10,000 properties in Tewkesbury were supplied with non drinkable water from Strensham WTW for sanitation purposes.

  4.10.  During the incident, customers were provided with alternative supplies through the use of bottles, tankers and bowsers. Bowser deployment began at 1715 hrs on Sunday 22 July and was rapidly scaled up. In the initial 48 hours demand was high, suggesting that some customers were taking more water than they needed for daily use and were stockpiling. We found it difficult in some locations to match the bowser refilling requirements with the high level of demand being experienced.

  4.11.  With the number of bowsers deployed, it was not possible to provide permanent supervision to prevent vandalism or ensure customers did not take excessive quantities and turned the taps off after use. Damaged bowsers were returned to our depot for repair, disinfection and re-issue, straining resources. At the peak of the incident response, in excess of 1,400 bowsers were deployed to more than 1,100 locations, the largest number ever used in a single incident in the UK, with up to three fills per day.

  4.12.  By Monday 23 July we were already sourcing 1 million litres of bottled water per day, which increased to 5 million litres per day by Friday 27 July. This was delivered through close collaboration with suppliers and those providing logistical support, including the councils and the army.

  4.13.  Following initial damage assessment on Tuesday 24 July, full access to the Mythe WTW was regained on Wednesday 25 July and the restoration of the works commenced. This included the removal of flooded motors for drying and/or replacement, checking and replacing control panels, and the industrial cleaning and disinfection of treatment tanks. A review of our ten main treatment processes indicated that eight had damaged equipment. Eleven major plant items were taken off site for repair and a further four were repaired on site. Within three days water was passing through the clarification and filtration treatment processes for test purposes only. We commenced the reconnection of properties on Sunday 29 July. Half of the properties affected had non drinkable water supplies restored, suitable for sanitation purposes, by Tuesday 31 July, moving to 98% reconnected by 0600 hrs on Wednesday 1 August. Remaining supplies were restored 24 hours later.

  4.14.  As a precautionary measure, we assumed that the restored water supply was not safe to drink until testing could confirm that it was of drinkable quality. The depressurisation of a distribution system on this scale and for such a prolonged period was without precedent in the UK water industry. Many of our mains were under substantial levels of standing floodwaters. Risk assessments of the impacts on water quality when supplies were restored included the possibility of flood water ingress to the system with the potential for faecal or chemical contamination.

  4.15.  We established a direct and open communication route with the Drinking Water Inspectorate (DWI). We produced a detailed sampling and analytical strategy aligned to the distribution recovery plan, agreed by the DWI and delivered within the timeline.

  4.16.  In total, approximately 1,450 samples were taken and more than 13,000 test results were produced in connection with this event.

  4.17.  We were able to move from "Do Not Drink" to "Boil Water" advice on Friday 3 August (within 2 days of full restoration of water supplies) and then to "Safe to Drink" on Tuesday 7 August (within a week of full restoration), ahead of the anticipated schedule.

  4.18.  Our current estimate of the costs of dealing with the incident is in the range of £25 million—£35 million, partially offset by insurance of between £10 million—£20 million. These figures are likely to be revised as the full extent of costs becomes clearer.

  4.19.  We worked closely alongside many agencies including the army, police, local authorities and our suppliers in responding to this emergency. We worked effectively with them as a team and pay tribute to their help and support.

  4.20.  Throughout the event we were in regular contact with the relevant regulatory authorities. We discussed with the Office of Water Services (Ofwat) and the Consumer Council for Water the position regarding the Guaranteed Standards Scheme (GSS). This compensation scheme provides payments to customers in the event of a failure to meet the standards. In consultation with Ofwat, it was determined that GSS payments do not apply in these circumstances given the exceptional nature of the weather and the unprecedented scale and speed of flooding. However, in recognition of the impact of the incident on our customers, we have allocated a fund of £3.5 million to benefit the affected communities and are working with key stakeholders to determine how these funds will be used.

  4.21.  Our communications strategy was to be open, honest and direct, updating our customers through all available channels, including the media and internet.

  4.22.  The scale of the incident and the presence of floodwaters necessitated the use of broadcast media to communicate information to our customers in preference to individual correspondence. Daily press conferences were given by Gold Command, including our senior representatives.

  4.23.  Our main company website failed on Sunday 22 July due to the number of people trying to access it. We increased the capacity of the website and returned it to service by 2100 hrs the same day, although it did continue to suffer slow response times.

  4.24.  All customer enquiries were handled by our Customer Operations Service Centre (COSC). To improve customer service, a second customer contact centre dealing with calls specific to the incident was opened on Thursday 26 July.


  5.1.  The flooding in Gloucester has raised 3 broad questions: first, the adequacy of flood defences; second, the extent of "redundancy" such that the failure of a key asset can be compensated by other means without interruption of service; and third, the adequacy of contingency planning should supplies fail.

5.2.  Flood defences

  The rainfall levels and the consequent river flooding were unprecedented. Prior to the event, we considered Mythe to be adequately protected. In the light of these events and climate change more generally, along with government agencies and other utilities, we should re-evaluate the levels of possible flood against which our assets should be protected. Some of the resulting additional defences may be specific to our sites. Others should be covered by government schemes designed to protect communities as a whole.

5.3.  Redundancy

  Mythe (WTW) is one of a group of key sites most of whose customers can receive water from no other treatment works. In consultation with our regulator, investment in redundancy (alternative supplies) has been focused on those communities judged to be at greatest risk, and those with the largest populations (for whom the provision of bowsers has been deemed to be less practical). To prevent a possible repetition of recent events, we should re-evaluate possible investments to increase the degree of redundancy of supply. We will work with our regulators and key stakeholders to develop means to ensure that we can proceed with the most effective schemes. Initial research carried out after the flood by CCW found that customers place very high value on continuity of supply, and support long term investment over short term compensation.

5.4.  Contingency

  The unprecedented scale of the flooding severely stretched our capabilities to provide alternative sources of water for drinking and sanitation. We do not believe any single water company would be able to cope with an incident of this scale on its own, even given effective "mutual aid" support from other water companies. While we believe that our response was effective in maintaining a supply of water to the community, we will continually review and improve our contingency planning.

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