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.
Severn Trent Water Limited
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. THE EVENT
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. OUR RESPONSE
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. INTERIM CONCLUSIONS
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
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.
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.
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.