Supplementary memorandum submitted by
the Environment Agency (FPO 7A)
DEVELOPMENT ON, OR AFFECTING, THE FLOODPLAIN
During the Agency's oral evidence, information
was requested by the committee on the following matters:
1. THAMES TIDAL
The Agency is developing a strategy for managing
flood risk throughout the whole estuary up until the year 2100.
Previous plans have only considered the years up to 2030, but
this has changed now due to the complexity of the systems involved,
and the potential long-term impact of any major strategy decisions,
which may be made over the next few years.
Preliminary investigations indicate that the
continued provision of a 1 in 1,000 defence standard to the year
2100 is feasible but modifications of the Thames Barrier and other
defences will be required. At present we estimate that investment
of £4,000 million will be needed over the next 40 years to
maintain the current standard of defence until 2100. This is based
on works to the existing barrier and defences. The Agency has
not actively investigated the building of a "lower Thames
Barrier", ie another Thames Barrier downstream of the existing
Current estimates are that sea level relative
to land could rise between 0.6 and 1.0 metre over the next 100
years in this part of the country. This is partly as a result
of the sea level rising, and partly due to post-glacial ground
levels falling. There is a considerable amount of uncertainty
over these figures and we are keeping close to the latest research
and scientific recommendations. Due to the funnelling effect of
the Thames Estuary, the effects of sea level rise are anticipated
to be greater closer to London than in the more open estuary.
It is expected that Climate Change will increase the frequency,
severity and unpredictability of storm and surge events. This
would affect tidal and fluvial flooding issues and our flood warning
procedures are being continuously improved.
Major developments have been built and others
are proposed, which would place increasing numbers of people at
risk in the event of extreme flooding. One example is Thamesmead
on the South Bank, where large numbers of houses are built as
low as four metres below normal high tide level, and are only
prevented from flooding by embankments and four substantial pumping
stations. Further development is proposed for this area, increasing
the reliance on these methods of flood defence.
2. KEY STATISTICSENVIRONMENT
|Number of planning applications seen by Environment Agency
|Number of seen by Flood Defence||17,568
|Number of objections on flood risk grounds
|Number of "maintained" objections
|Number of planning permissions granted against Agency advice
These statistics are a crude snapshot of the extent to which
decisions on Planning Applications address flood risk issues under
current guidance. The statistics do not reflect in any way the
scale or location of development, nor cumulative increases in
flood risk arising from development and changes in land management.
A broader picture is provided by considering the amount of
development proposed in floodplains (from commercial databases).
For example, 4,000 houses were proposed in floodplains in 1996,
compared with 20,000 so far this year.
The statistics do not provide a full analysis of flood risk
issues in the development and planning processes. The effectiveness
of the PPG should be evaluated against the performance of Regional
Planning Guidance and Development Plans in achieving safe development.
These data show that further work is needed to ensure that
PPG 25 achieves the intended policy objectives.
3. CALL IN
Planning applications of more than local significance can
be "called in" by the Secretary of State. The Agency
has no more power than any member of the public does to require
that a planning application is "called in". The Agency
has not made any requests to the Secretary of State for planning
applications to be "called in" between April 1999 and
The Agency will maintain necessary objections to policies
and/or land allocations in Regional Planning Guidance and Development
Plans to ensure that those policies and land allocations are considered
by the Secretary of State or Planning Inspectorate.
The statistics provided by the Agency in its evidence reflect
the impact of the considerable efforts of the Agency to persuade
Planning Authorities of the significance of flood risks. The serious
floods of Easter 1998 in the Midlands and subsequently elsewhere
have helped make this persuasion successful.
The Agency's experience, however, is that the memory of flooding
in the planning system can be short-lived, 2-4 years. The Agency
is therefore concerned that, in the absence of a strong, clear,
Government policy on development in flood risk areas, a few flood
free years will result in progressively less success in influencing
the planning system.
Dr Geoff Mance
Director of Water Management
30 November 2000