Supplementary memorandum submitted by
National Grid (FL 80a)
Many thanks to you for your letter of 18th February.
My colleague Nick Winser and I welcomed the opportunity to update
the Committee on the impact of the summer 2007 floods on our operations
during our evidence session.
As you are aware National Grid owns and operates
the high voltage electricity transmission system in England and
Wales and operates the system in Scotland. In addition, we manage
the gas transmission system in the UK and distribute gas to 11
million homes and business in the heart of England.
Following the summer floods, we have invested
£1million in mobile flood barriers to be deployed to electricity
substation sites at risk of flooding. In addition, we invested
£300,000 for a medium term Hesco Bastion wall at Walham 400KV
substation. We have undertaken a full review of all our electricity
and gas sites, and are working closely with the Energy Networks
Association to review substation resilience to floodinga
report on the findings of this group has been submitted to BERR
this week. In addition, we continue to work closely with Sir Michael
Pitt and his flood review team on resilience issues.
One of the issues raised by the Committee during
the evidence session which we would very much like to take the
opportunity to address once more, is that National Grid has a
99.9999% reliability rate in its operation of the electricity
transmission network. To date flooding has not posed the most
serious risk to the reliability of the network; however, we work
closely with the Met Office and Environment Agency to assess the
impact of weather on our system and we are therefore undertaking
R&D to understand future requirements.
Addressing the impact of flood waters on our
gas network has also been a significant work stream for National
Grid in the last few years. In 2006, we commissioned a review
to assess our gas transmission sites analysing the assets at risk
from flooding. This study examined our four broad asset groups
on the gas networkPressure Reduction Stations, Holder Stations,
High pressure Pipelines and Low pressure gas networks. We also
commissioned an engineering review in July 2007 to consider the
risk posed by different levels of flood water.
As I mentioned in the evidence session to the
Committee, we do look at the issue of moving assets at risk of
flooding, particularly those of a critical nature. In terms of
electricity substations the majority of transmission network was
built in the 1960s based on best information available, any new
site will be constructed to latest standards and will be designed
to be safe and operable to 1 in 1,000 year floods. The research
we have commissioned to date shows that it is not cost effective
to relocate all sub stations in high risk zones. As such we will
be taking steps to enhance defences around critical substations,
and following the Energy Networks Association review on substation
resilience we will be taking advice on which sites may need permanent
barriers. We estimate that these will cost in the region of £30-£75
million and take 5-7 years to install.
On the issue of resilience and our obligations under
the Civil Contingencies Act, I would like to take the opportunity
to reiterate that National Grid has a well developed emergency
framework which it frequently tests. The framework has been developed
in liaison with other energy sector companies and the lead government
department BERR. In turn, the BERR emergency framework dovetails
with COBRA. These arrangements are currently reviewed and improved
through the industry planning body, the Energy Emergencies Executive
Committee (E3C) which is chaired by my colleague Chris Train.
E3C reports to E3 which is chaired at an executive level by BERR.
It is with pleasure and pride that I reflect
that a number of our operational engineers who worked extremely
hard through the summer floods have received honours for the hard
work and dedication to National Grid and the communities in which
we operate. I particularly would like to note and give thanks
to Andy Wilson, a National Grid First Call Operative who saved
the life of a kidney patient, when their dialysis machine was
affected by localised power cuts; Dan Bailey, a National Grid
Transmission craftsman who set up a support rope and negotiated
a flooded road to deliver insulin to a diabetic youngster trapped
in a nursery; and Paul Jones our Distribution Operations engineer
who was first on the scene at Ludlow, where a bridge had collapsed
leaving a gas main exposed. He ensured the safety of the public
and coordinated the response of the emergency services when they
The flooding events of 2007 clearly demonstrated
that our commitment to and close working with the Silver and Gold
commands ensured effective response in managing events at Walham
and South Yorkshire. I would also like to thank the emergency
services, army and all those who provided tremendous support to
National Grid during summer 2007.
Many thanks to you for the opportunity to appear
before the Environment Food and Rural Affairs Committee.
Chris J Murray
Director of Asset Management