Examination of Witnesses (Questions 852
MONDAY 4 FEBRUARY 2008
To quote a very old radio phrase: if we are all sitting comfortably,
then we will begin. Can I welcome to our inquiry this afternoon
from Central Networksthis is not, I must add, a railway
company that is before us, it is to do with electricity distributionMr
Alan Raymant, the Director of Operations and Asset Management,
and from National Grid, Mr Nick Windsor, the Executive Director
of Transmission, and Mr Chris Murray, the Director of Asset Management.
Gentlemen, the facilities that you have responsibility for certainly
hit the headlines in the flooding last summer and a lot of questions
about resilience and preparedness to protect these valuable assets
from the inundation and the effects that they would have have
been raised by none other than the many thousands of members of
the public who had their power cut off, but let me just go back
a little bit before last summer's flooding. When the former Chief
Scientist, Sir David King, produced the Foresight Report, in which
he put forward a number of scenarios as to what could happen in
the United Kingdom due to climate change and extreme weather events,
what did your respective organisations do when that report was
Mr Raymant: From Central Network's
perspective we had identified as part of that a number of sites
that were at potential risk of flooding, and we identified 81
potentially critical sites depending on the extent of the flooding.
The next step of work was to identify exactly what the risk was,
quantifying the risk and the precise likelihood of flooding and,
therefore, damage to the equipment. That work was commenced then
and is on going.
What about National Grid?
Mr Winser: From the National Grid
perspective, we have always taken account of the possibility of
flooding to our assets right back in our heritage to the Central
Electricity Generating Board. Of course, a lot of our sites, in
fact virtually all of our sites, were a product of going through
siting and planning in the 1960s. There have been a number of
things that have focused us in recent years, not least Sir David
King's work but also the floods in Carlisle, and we had already
kicked off work with the Meteorological Office Hadley Centre which
was to look at what might be the overall effects on our system.
We had also, as a result of the Carlisle floods, commissioned
a study looking at all of our assets once again to check, as the
understanding of these effects was becoming greater, how they
would be resilient against those risks.
So Foresight did not trigger, in your judgment, any new activity
but added to your knowledge about existing activity?
Mr Winser: Yes, I think so. We
had been spurred on to a significant degree of activity by the
Carlisle floods actually in 2005, but this had always been very
much part of the way that we planned the system, and we have been
working with the Met Office.
If you had done all this work and spotted all the potential risk
sites, why did we have any problems in the summer?
Mr Winser: From our perspective
there were two events which are worthy of debate. Firstly, the
floods in Sheffield, which Chris will talk to you in a second
about if you would not mind, Chris, and, secondly, the events
round Gloucestershire. Of course, we did lose some supply in Sheffield,
a very rare occurrence on the transmission system, by transmission
standards quite a small loss of supply. Of course, at Walham,
despite there being, as was well covered in the media, quite a
close shave, there was no loss of supply at all from our facilities
in Walham. It is important to make that clear, I think. Chris,
do you want to talk about Neepsend?
Before we leave Walham, what did that show up, in terms of all
this work you were doing, if you like, post Foresight: because
the one thing about Foresight was it warned us about extreme weather
events and one, I think, could say with some accuracy that last
summer was extreme. You seem to be working very hard with the
Met Office doing all of these things, but you just told us it
was a close shave. Did Walham come up as a risk site?
Mr Winser: Walham is a very interesting
sort of example of the history of this. Walham, as far as we can
understand, when it was sited in the sixties and, indeed, thereafter
as we looked at the likely flood contours from the EA, was something
of the order of quite a low risk actually. Although it was quite
close to the flood plain, it was deliberately on raised ground.
We have not managed to surface documents from the sixties to say
exactly what went into its siting, but it was on raised ground
and actually featured at something like one in a thousand, which
is, by the way PPS25 works, pretty remote. In recent years (and
these are very recent years), as we have got better and better
understanding from the EA publishing better and better flood contours,
actually the assessment of Walham has gone from one in a thousand
to one in 200.
Mr Murray: One in 75.
Mr Winser: One in 75.
Over what time period was that?
Mr Murray: That is over about
the last two years, Chairman. One has to remember that this site
was built in the 1960s. The whole area around it is subject to
flooding, but this site has never flooded.
The area is subject to flooding, the risk factor has gone down
from one in a thousand to one in 75. What did you do when you
discovered that this was now a more vulnerable site? Did you actually
take any specific additional measures to protect it? As you said,
you ended up with a close shave. What I am probing for is to find
out how, in the light of all of the information that has become
available (and some of it you have alluded to), we still end up
with a close shave at one in 75? I can understand one in a thousand.
That is a pretty extreme event by anybody's standards.
Mr Winser: Although it had only
dropped to one in 75 in literally the last year or two, a period
in which we were doing intensive work following Carlisle which
revealed, as is in our submission, that there were about 28, quite
a small proportion, less than a tenth, of our sites that were
in areas which may have some vulnerability to flooding. Therefore,
it was a matter of engaging with our colleagues in the distribution
networks and in particular with the EA to understand the impact
Was Walham one of the 23 that you mention in paragraph 11 of your
Mr Murray: Not at that time.
Mr Winser: Not at that time, because
it was still up at one in 200 at the time. The development of
this may seem curious to the Committee but this is as we have
had access through much better IS, I guess, as we have seen the
use of GIS and flood contours become more available. Whilst this
is a capability these days, it is a relatively recent one actually,
and that probably explains why Walham has moved so much in the
probabilities. Of course, having had the events of the summer,
we have spent a considerable amount of money not only putting
up a semi-permanent barrier around Walham, which is there today,
but also we have spent over a million in total buying a relocatable
flood barrier which can be deployed as we get warnings from the
2 Ev 308 Back