Examination of Witnesses (Questions 200
- 219)
WEDNESDAY 14 NOVEMBER 2007
MR KIM
RYLEY, PROFESSOR
TOM COULTHARD,
SIR ROBERT
KERSLAKE, COUNCILLOR
JAN WILSON
AND MR
JOHN CHARLTON
Q200 Patrick Hall:
Mr Ryley touched on a very important issue, which is the implications
for planning policy. Could I ask, what were those proposals that
were refused following the flood which otherwise would not have
been refused?
Mr Ryley: It was for a small scale
housing development. It was literally a handful of houses, a very
small scale development in a particularly sensitive area.
Q201 Patrick Hall:
I suppose you are not able to draw any conclusions from that with
regard to regional or national planning policy guidance. The decision
either way would have been consistent with national policy guidance,
would it?
Mr Ryley: Yes, with the supplementary
local design guidance that our planning committee has adopted
in the light of—
Q202 Patrick Hall:
It is an entirely local matter.
Mr Ryley: Yes.
Q203 Patrick Hall:
Clearly what we have got to be thinking about is some of the larger
scale growth areas and the implications and lessons that can be
drawn, but possibly not from a handful of houses.
Mr Ryley: If I could answer the
question slightly differently because one of the issues we are
wrestling with now is we are looking at the reconstruction issues
coming out of this, for example things around schools, since we
are in a major programme of rebuilding for secondary schools in
the city and our schools were particularly badly damaged disproportionately
in terms of effect and number because of the way their grounds
soak up water and act as reservoirs, if you like, on these occasions.
Certainly we are looking at fundamentally changing our design
model for future school building to make them more flood-proof,
to change their footprint in that sense, to build vertically rather
than horizontally, for example. Those sorts of issues are now
starting to come out of these experiences and I think they are
going to give rise to some significant rethinking of how we design
and build key public facilities in the future.
Q204 Patrick Hall:
Is Sheffield thinking about its planning policies in the light
of the flood?
Sir Robert Kerslake: As John said,
the assessment we had was that the patterns we would have predicted
for what was a 150 year event were what happened, so the basic
analysis of prediction on flood risk was correct. What we are
doing for the planning policy is looking at the resilience of
individual developments to flooding, which seems to me as important
here. Much can be done in the way developments are designed, not
to eliminate risk but to reduce the impact. Our focus and effort
is on that issue.
Q205 Paddy Tipping:
I want to focus on the inability of the urban drainage system
to cope with the event. Perhaps colleagues from Hull could help
me with this. Professor Coulthard, you were very keen to tell
us at the beginning of the session about the map that had been
delivered for the first time.
Professor Coulthard: Yes.
Q206 Paddy Tipping:
Who took the lead on that? Second, there is an issue, and I have
been pursuing this myself, about responsibilities. Is there an
agreement on your map—I hope there is—that this bit
of the system is the responsibility of X and Y?
Professor Coulthard: That is a
very good question.
Q207 Paddy Tipping:
What about riparian owners? They do not seem to know what their
responsibilities are, do they?
Professor Coulthard: First of
all, I believe the Environment Agency created that map in collaboration
with the council. Second, there are some stretches of watercourse
in Hull where there is some ambiguity over the owner, shall we
say. That partly occurs because you may have had a piece of watercourse,
which is an Agency responsibility, that has then become culverted,
and in some places you can have watercourse/culvert, watercourse/culvert,
watercourse/culvert, and sensibly instead of saying "Council/EA,
Council/EA", they have put a line down each end of it and
put "?". That is part of the issue we are dealing with
here. With regard to riparian ownership, I cannot really comment
on that because I do not feel I have sufficient knowledge in this
area in the context of Hull to comment.
Q208 David Lepper:
I am just trying to get clear in my mind the scale of distances
that we might be talking about. In the example that you gave,
for instance, of an open stretch of water/culvert, open stretch
of water/culvert, are we talking in terms of stretches of several
metres or miles?
Professor Coulthard: In the case
of the watercourse/culvert, watercourse/culvert, you are talking
about distances of ten to 20 to 30 metres. In some cases you can
have a piece of watercourse that is several kilometres and then
it may be culverted for a kilometre and open watercourse again.
The situation in Hull is complex because some watercourses flow
both ways depending on what the levels of water are, depending
on how it is being pumped and how the tide is. It is not an amusing
map but an interesting map because it has some arrows pointing
in both directions and different shading in different parts.
Q209 Paddy Tipping:
How are you going to sort this out then?
Professor Coulthard: It is not
for me to sort out, it is for me to flag up that there is an issue
here. It is encouraging that the Environment Agency, the council
and Yorkshire Water are getting together and talking about this.
I hope someone takes a lead and I hope they get together on this.
The evidence is that is occurring.
Mr Ryley: I think our intention
in the absence of any direction coming through nationally in the
short-term was as soon as we have the missing piece of the jigsaw
we could start to plan jointly with more confidence. A complete
approach to this issue was to have a formal agreement between
the three main partners that would bind us into specific actions
as well as a joint liability and approach to the future.
Q210 Paddy Tipping:
Can I turn to the issue of the maintenance of the gullies. I will
bring the ceiling down here. There are a lot of pressures on local
councils and you are asked to spend lots of money with a limited
pot. People say to me that part of the problem with the flooding
was the cleaning of the gullies had not taken place. Is there
some substance in that?
Professor Coulthard: In Hull,
as part of the Review we looked at the statistics provided by
the contractor who cleans the gullies and I believe they showed
that less than five per cent of the gullies when they checked
them after the floods were blocked. In my opinion, it may have
been a factor in certain locales but in general I do not think
it was an issue.
Mr Ryley: Just by comparison,
our neighbouring authority in the East Riding, which had a different
frequency of gully clearing and maintenance from us, still experienced
the same problems about the drainage system being over-capacity.
Professor Coulthard: There is
a difficulty here in that the symptoms of a gully being blocked
and the sewer below the gully being capable of draining the water
away are exactly the same.
Q211 Paddy Tipping:
I know colleagues from Sheffield will want to come in, but whilst
you are answering let me ask you about the problem of parked cars
because that is an issue as well if you cannot get to the gullies.
Mr Charlton: We have an inventory
of our gullies in Sheffield. There are 72,000 gullies in the city
and we clean them all once a year, some more frequently. We also
monitor how many are running freely. Currently 94 per cent are
running freely. The six per cent that are not running freely are
predominantly due to issues such as parked cars where it is very
difficult to move people. To work with the police and get a formal
road closure, clamp cars and move them might cost £1,500
and it is not the best use of money, we could clean however many
dozen gullies out for that. We try by persuasion, to leaflet people
in advance, "We will be on your street this day, will you
please move your car". The majority of people co-operate
but there are always some people who do not co-operate. It was
not an issue for Sheffield particularly on the day. Prior to the
main rivers overtopping the surface water drainage system—80
per cent of the gullies flow into combined sewers which are Yorkshire
Water's—was working pretty well okay until the rivers began
to rise and overtop and then the rivers and the road became as
one on the whole floodplain down the Upper and Lower Don.
Q212 Paddy Tipping:
Finally, I wanted to ask you both about one of the comments from
one of the Environment Ministers who said if we had had water
butts in place and stopped people concreting over the gardens
for car parking it would have made all the difference. How much
difference do you think it would have made?
Mr Charlton: In the great scale
of things it would have made minimal difference. It will make
a difference. If it was previously someone's garden water would
soak away but when it is concreted it does not soak away, it sheds
into the drainage systems and asks more of the rivers. Obviously
it makes a different but in the great scale of things on the 25
it would not have made any difference at all on the day.
Professor Coulthard: Certainly
in Hull, and I imagine in Sheffield, the ground was already pretty
wet from a very heavy rainfall event on 15 June.
Q213 Chairman:
You mentioned that you had a little run-out with an emergency
plan, your advance warning. What was the scenario that you used
because in your evidence you say: "Sheffield is an area of
low flood risk" and yet quite clearly a series of events
conspired to put you right at the heart of a deluge? Who designed
the trial and what were the assumptions you used?
Sir Robert Kerslake: The assumptions
were fairly uncannily close to what actually happened. It was
done as a test really to test our emergency planning procedures
in the same way as you might do a test using a terrorist incident
or whatever, but on this occasion we happened to do a flood risk
incident. It was not with any view to that happening in Sheffield,
it was simply to use that as an example. We have also done one
on terrorism and so on. The scenario was very much the same situation
of rapid flooding cutting off the city.
Mr Charlton: It was called Operation
Loxley. Loxley Dam in 1864 burst and 250 lives were lost in Sheffield.
The dam burst and it came down the Loxley Valley, which hits the
River Don in Hillsborough just near the football ground. The dam
burst and there was a flood coming in from the north of the city,
which was pretty much exactly what happened on the day. It was
called Loxley because everybody in Sheffield is aware of the history
of 1864 and the previous great flood.
Q214 Chairman:
The nature of your Flood Risk Assessment was, "Here's a scenario,
now let's see how we cope with the consequences", as opposed
to a piece of perceptive exercise where you said, "Oh, look,
if this happened for real then there are some serious issues that
we have to ask about the city's drainage arrangements to actually
cope with the water before it becomes a flood"? You were
not in that business, you were in a "how do we cope"
exercise.
Sir Robert Kerslake: It was absolutely
about the response to an emergency, that was what we were testing
through our exercise.
Q215 Chairman:
On the question of prediction, in Hull's evidence you said at
paragraph 10.1: " ... a first key step should be a major
hydraulic study to model flows in the city as a whole ... "[3].
One of the things I found quite intriguing, given that you have
got a very special series of drainage issues, having a pumped
as opposed to a gravity based system, was that nobody had done
that before.
Professor Coulthard: Yes, I agree.
Q216 Chairman:
If that is the case, without wanting to lead you to your final
conclusions, is that kind of evaluative exercise something which
might more generally be applied in our major urban centres?
Professor Coulthard: Yes. To an
extent it has been done before. In the second part of our investigation
we are going through reports that Yorkshire Water have whereby
they have modelled for looking at the capacity of their sewerage
system. They have modelled what areas might be at risk of flooding
in a range of different scenarios. These maps are certainly not
publicly available, they are within a consultant's report to Yorkshire
Water, I guess they are an internal document. There is no scheme
or method for doing this. I think this has got to be a national
issue in that our whole flood forecasting warning system is geared
up to deal with estuarine and fluvial flooding and, please someone
correct me if I am wrong, I do not believe there is any predictive
modelling done looking at urban flash flooding or pluvial flooding
events, and that is a real gap.
Q217 Dr Strang:
If I can bring Sheffield back to the Strategic Flood Risk Assessment,
which you have explained was in place before the flooding, how
useful has the preparation of the Strategic Flood Risk Assessment
been in considering the risk of flooding in the future?
Sir Robert Kerslake: I think very
helpful because it gives a comprehensive assessment and it also
allows us to reassess risk in the light of events for particular
situations in particular parts of the city. What it did give us,
as John has indicated, was a pretty clear indication of how the
flooding would impact on the city if and when it occurred. The
third thing it has done for us is help us with individual assessments
of development that might go on in the city. In many different
ways it has been incredibly helpful. It is important as well in
my view, and I just make this point, to avoid the risk of being
overcautious about the impact of flooding just as it is about
being excessively lax about it, if I can put it that way. If we
take an overcautious view we risk undermining the development
and economic growth of the city. If we have got the right risk
assessment that will enable us to make the right judgment on development
in the city and that is where it has been critical.
Mr Ryley: Can I emphasise that
same point because it is quite important from Hull's perspective
as well. We are a city that has been there 700 years, was built
on a marsh and it used to flood regularly until our flood defences
were put in place and 95 per cent of the city is in a high flood
risk area. On that basis, if you were overcautious there would
be no further development in Hull and that is clearly not the
way the city has worked in the past and it cannot be the way we
work in the future. From our own Flood Risk Assessment we are
making the same careful judgments about risk and levels of acceptable
response and acceptable development on that basis and it is proving
very valuable. The other thing Hull is doing as a port city, in
common perhaps with other port cities in the UK where there are
a different set of issues for us perhaps, is we are looking to
collaborate in a pan-European study with Rotterdam, Copenhagen
and Hamburg looking at the particular issues of flooding in port
cities which operate a different kind of industrial complex with
docks and other things. We are going to try and learn from best
practice on a European level as well. That will be of particular
value to a range of other UK port cities as well.
Q218 Dr Strang:
You are saying that the assessment will influence your Local Development
Framework.
Mr Ryley: Absolutely.
Q219 Dr Strang:
In the assessment you recommended that you review flood risk management
policy in relation to development and emergency planning. Do you
have any changes in mind at the moment?
Sir Robert Kerslake: What I meant
in terms of the Strategic Risk Assessment was that it enables
us to judge the likelihood of different risk in different places
and we have changed the categories of that risk in the light of
the events that occurred. In terms of emergency planning, that
is probably driven by a different set of issues. The thing that
we did learn from this process was the need for resilience over
a long period. The most important thing is to have a wide range
of people trained and capable to manage emergencies because actually
it is incredibly tiring over one or two days and you need to have
standby and cover arrangements. If I was to go back to our own
situation, a key issue would be about the capacity to manage an
emergency over a longer period. That was a critical issue for
us. You need to have resilience and strength in-depth, in other
words.
Mr Ryley: Can I pick up the comments
that were made earlier about training. Our evidence is we have
had a major training exercise based on flooding within the last
few years, although that again was based on tidal flooding, so
it was not quite the same scenario, and that identified a number
of issues which we had picked up and put in place. What we found
was even within that limited window, by the time the flooding
arrived there had been a significant turnover of key staff in
all of the agencies involved, so we had a lot of people we had
not had time to train in-depth. They learnt a lot on the job and
responded magnificently at the time but it raised with us the
fact that the frequency of this is crucial. Doing it every three
years, which was the model in the past, probably is not enough.
It is the need to have a range of people on hand to give you that
resilience and also in-depth training on a much more regular basis.
Professor Coulthard: A lot of
the success at the local level of Hull's response to what happened
was because they knew each other, they had each other's mobile
phone numbers, they had worked with each other before, and that
kind of local networking is really important. One of the things
we would like to see is that these groups get together more often,
every six months or every year, and maybe not go through such
a rigorous training exercise but know each other and know who
they are dealing with. Those relationships are really important
in this type of situation.
3 Ev 57 Back
| 
