Infrastructure Delivery Plan (Feb 2013) - Runnymede Borough Council

of works within the context of a 100 year strategic plan. The LTFRMS will reduce the
risk of river flooding to 15,000 properties with a one per cent annual (1 in 100 year)
chance of flooding from Datchet to Teddington. Measures proposed in the strategy
include:
• building three flood diversion channels (Channel 1 would run from Datchet to
Wraysbury; Channel 2 from Egham to Chertsey and Channel 3 from Chertsey
to Shepperton)
• widening or deepening of the DesBorough Cut
• capacity increases to Sunbury, Molesey, and Teddington weirs
• Individual property protection measures for improving resistance against
flooding for smaller groups of properties
• improving mapping information for emergency evacuation plans
13.56 Specifically, within Chertsey, both local and combined flood impacts from the Chertsey
Bourne and the River Thames are known to be significant. There are numerous
tributaries and minor drainage channels in the area and many would receive some
reduction in flood risk due to the proposed diversion channels, which would reduce
flood levels generally. The Chertsey Bourne system, incorporating the Mead Lake Ditch
and Moat, has been assessed as receiving significant benefits from diversion Channel
2. A previous study into the flooding impacts of the Chertsey Bourne was included into
the wider Lower Thames Strategy.
13.57 In regard to the community based measures for improving resistance against flooding
for smaller groups of properties, within the Borough, the Environment Agency have
assessed a number of properties in Timsway, Coopers Close and Staines Lane (all in
Staines). Work was carried out to identified properties in 2012 following survey reports
carried out by the Environment Agency for the residents.
13.58 Given the difficulties with securing the funding for the project however (for more
information on this please see the ‘costs and funding sources’ section below), works
will be delivered through separate projects. According to the Environment Agency,
works are unlikely to start in 2017 as originally stated. During the Local Plan period, it is
only the individual property protection works proposed under the LTFRMS which will be
carried out in Runnymede. The civil works and cut works are planned to take place
after 2026.
13.59 The River Wey Flood Risk Management Strategy which was previously proposed has
now largely been abandoned although the Environment Agency advise that they are
continuing their work on the refurbishment of the weirs along the route.
Costs and funding sources
13.60 The Whole Life Cost (excluding inflation) of the LTFRMS is £538m including a
contingency of £101m. As a consequence of the Government’s 2010 Comprehensive
Spending Review however, Defra has instructed the Environment Agency to reduce
their capital expenditure by 27% by 2014. This has implications on the size of their
capital programme and their proposed schemes. In June 2011, Defra introduced a new
policy of Partnership Funding. This scheme enables a greater number of schemes to
receive at least some capital funding, with the remaining amount being made up from
external contributions. Fewer schemes will however receive 100% Defra Grant in Aid
(GiA) funding.
13.61 When the Environment Agency undertook the public consultation for the LTFRMS in
2009, the scheme was eligible for 100% Defra funding, based on the strength of the
business case. The change in policy means that the delivery of the LTS will now
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Runnymede IDP DRAFT – February 2013