Memorandum submitted by Alison Cobb (FL
76)
A DISASTER TO COME: NOTES ON FLOODING IN
BINSEY AND WEST OXFORD IN 2000, 2003, 2007
SUMMARY
This submission examines the experience of recent
flood events in West Oxford, centred on Port Meadow, the village
of Binsey and adjacent river channels.
It places the blame on the Environment Agency
for failure to maintain river channels, failure to maintain the
embankment of the main River Thames, and failure to broadcast
accurate and timely information during the floods. Simple remedies
are recommended.
INTRODUCTION: BINSEY
AND WEST
OXFORD
1. This submission is centred on the Thames
floodplain, on the western edge of the city of Oxford. It describes
some of the experiences of the village of Binsey, a small isolated
rural hamlet in the centre of this floodplain (but within Oxford
City), during the floods of December 2000, January 2003 and July
2007.
2. Only residents of Binsey can know what
happens during severe floods because Binsey is cut off by one
mile of flood water in all directions. Neither Environment Agency
nor Oxford City officials can, or do, get to the village at these
times.
3. Binsey, "Ben's Eyot" or island,
lies between the river Thames to the East, and its old course
the Seacourt Stream to the West, which branches off the Thames
above Oxford, and rejoins it below the city. As it goes through
Oxford, the Thames fragments into a number of smaller channels
(Seacourt Stream, Castle Mill Stream, Bullstake Stream, Hinksey
Stream). These are not tributaries: they leave the main channel
and rejoin it a few miles downstream. They are an integral part
of the Thames.
PORT MEADOW
4. There is a large lake, or area of flood
water storage, called Port Meadow, about one mile N-S, and half
a mile E-W, which when full stands about one metre above low lying
parts of Oxford. Port Meadow is immediately to the east of the
village of Binsey.
5. The natural reservoir of Port Meadow
is enhanced by an embankment on the West side of the Thames, one
metre high, thirty metres wide. In the recent floods, this has
been overtopped. This overtopping worsened with each of the last
three floods, and in at least ten places along Port Meadow the
bank is eroded. In the last flood, water came over the bank for
a length of 150 metres in one place.
6. The overtopping happens suddenly. An
enormous volume of water cascades into the low lying floodplain
around Binsey, and follows the lie of the land South into Botley
and Osney, flooding several hundred houses this time. This is
one reason why Oxford floods.
SUBSIDIARY CHANNELS
7. A series of 10 maps from 1792 to 1944
show a connecting stream between the Thames at the North end of
Port Meadow (which is the last part to fill with flood water)
to the Seacourt Stream. In early maps, it is simply named "Swift
Ditch". In eight later maps, the point where it leaves Port
Meadow is labelled "Overflow". Its course is often indicated
with flow arrows. The map currently provided to flood wardens
by the Environment Agency also distinguishes it, and no other
nearby stream, with flow arrows.
8. Swift Ditch and the Seacourt Stream are
now blocked with growing vegetation and fallen trees. The Seacourt
Stream was visited by kayak during the height of the floods: the
craft did not move, since the stream was not flowing, even though
water was flowing strongly across the adjacent meadows. There
were fallen willows every fifty metres or so at that point. Neither
the old "overflow" of Swift Ditch, nor the natural drainage
of the Seacourt Stream, is able to work properly.
THE ROLE
OF THE
ENVIRONMENT AGENCY
9. After each flood the residents of Binsey
tell the Environment Agency what happened; which they cannot otherwise
know because they cannot get into Binsey during the floods. After
each event we have walked the embankment with representatives
of the Agency. Each time they say this is bad, something needs
to be done. But nothing is done.
10. The Environment Agency is shown, on
its own maps, to have a "power" over the Seacourt Stream.
It does not exercise this power. We have recently (8th September
2007) canoed its central reach between Wytham village and Duke
Street, West Oxford, and twenty-two fallen willows, ashes and
hawthorn trees lie across it, blocking it.
11. If Swift Ditch is not part of the Environment
Agency's responsibility, surely it should be? In living memory
it was always maintained and kept flowing by the Thames Conservancy.
An overflow for Port Meadow would be a help in alleviating serious
floods.
12. People with long memories claim that
the flood regime for the last three floods has been different.
Flood water used to flow West, towards the Seacourt Stream. In
these last floods, as never before, the Thames overtopped its
embankment. As the embankment erodes, this becomes more dangerous.
We believe we may have a New Orleans situation here. There, the
levees broke: the city flooded. Afterwards it was discovered that
the authorities had known about the weakening levees, but had
done nothing to safeguard them. We have shown and told the Environment
Agency three times, after each flood, about the new overtopping
and eroding of the Thames embankment. And they have done nothing.
A larger area of Oxford floods each time. Next time it may be
disaster big-time.
13. The Environment Agency is making no
new flood wardens. It hopes instead to involve "the community"
in flood warnings. The experience of one flood warden is that
the tinny voice on the telephone announcing a severe flood event
is no substitute for being telephoned or e-mailed by a known person
telling you. As the flood waters are rising dangerously, "the
community" will all be busy taking valuable stuff upstairs,
ripping up the carpets, and so on. Only a volunteer flood warden,
who knows it is his or her duty, gets on the telephone at that
time and warns people, before dealing with their own disaster.
14. There has been great indignation in
Oxford at the inaccuracy of the Environment Agency's warnings.
At one point they said the peak flood would come at eleven o'clock
that morning, sorry, four o'clock that afternoon, sorry, seven
o'clock that evening, sorry, during the night, and they announced
the next day that the level was going down. A stick stuck in a
lawn in Binsey measured in inches (because inches are easier to
read with binoculars than centimetres, though conversion is easy),
showed in that afternoon when levels were supposed to be dropping,
in fact the water level was rising one centimetre every hour and
a half. This looked like a peak coming, and we told the Environment
Agency, who said they would pass it on. When we heard no announcement,
we e-mailed Radio Oxford (who deserve high praise for their up-to-date
handling of news of the latest floods) and asked them to put out
a warning, which they did. We were then telephoned by the Environment
Agency, asking what we were doing spreading alarm and despondency?
We were right, an hour later the highest flood level of all hit
Botley and Osney.
RECOMMENDATIONS
15. We suggest that the money and the means
be given to the Environment Agency, and that they be spurred into
action, to deal with the weakening embankment along the West side
of Port Meadow, and renew and maintain the ability of Swift Ditch
and the Seacourt Stream to take the overflow.
16. We suggest that more voluntary flood
wardens be appointed. Two other villages North of Oxford, Wytham
and Wolvercote, with no flood wardens, had no warning and suffered
severe flooding, and 39 sheep drowned in Wytham. We suggest that
flood wardens, instead of being issued with unnecessary yellow
jackets, be given a measured stick to push in somewhere where
they can easily read it. The absolute depth of the water is not
so important as the rate at which it is rising, and anyone watching
a measured stick can tell that. Had Wytham and Wolvercote had
flood wardens with measured sticks, the rate of rise of waters
in these two villages, which are above Binsey, would have given
much earlier, and much more accurate warnings than those of the
Environment Agency. The Environment Agency takes its data from
the locks, the worst place in which to measure flood depths, and
has proved to be dangerously inaccurate.
Alison Cobb
Flood Warden for Binsey; Press Officer, Binsey Residents
Association
August 2007
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