Twenty-eighth Report Adapting Institutions to Climate Change Cm ...

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ordinary watercourses. As with the national strategies these will be required to set out objectives
for managing local flood risk as well as the measures to achieve them. In contrast to the national
strategies, however, there would be no specific obligations on local authorities to consider the
impact of climate change.
For our purposes, it is important to note that the Bill contains a broad definition of risk
management which would provide additional flexibility for decision-makers. As well as hard
engineering solutions, risk management measures might include, for example, “maintaining or
restoring natural processes” or “making arrangements for forecasting”. 60
Local authorities are to be given responsibility under the Bill for surface water flooding, a major
source of flooding in 2007. The central role of local authorities in surface water flooding reflects
the growing need to manage flood risk through the use of sustainable drainage systems by soft
engineering and effective management of the urban infrastructure, and not just through specific
flood defence works. There is a need to clarify responsibilities for private surface sewers and
public water sewers not owned by the water companies – we understand that a lack of clarity has
caused problems in the past.
We were particularly interested in an approach to sea flood defences adopted by the Environment
Agency with the Thames Estuary 2100 project. One of the prime functions of the Thames Barrier
(Figure 3-VI) is to protect London and its estuary from tidal surges entering from the North Sea.
The area under protection includes the Thames estuary, its tidal tributaries and the related flood
plain. This area encompasses 500,000 homes and 40,000 non-residential buildings, including
key government and financial centres in London. In addition the area is one of the five most
important estuaries in Europe for birds.
FIGURE 3-VI
The Thames Barrier – one of the largest movable flood barriers in the world 61
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Chapter 3