SLP KDBH Extracts - Flipbook - Page 106
343.
The Council is the Lead Local Flood Authority for Solihull and has published a Local Flood
Risk Management Strategy to help reduce flood risk and mitigate the impact of flooding in
the Borough. Developers will be expected to review and pay due regard to the
recommendations included within the Local Flood Risk Strategy produced by the Lead Local
Flood Authority. The Strategy may highlight opportunities to work in partnership with the
Environment Agency and the Lead Local Flood Authority to contribute to the reduction of
flood risk to new development and to third party land.
344.
The Level 1 Strategic Flood Risk Assessment for Solihull has identified the main flood risk
areas within the Borough taking account of climate change and has been used alongside the
Environment Agency’s flood zone and risk of flooding from surface water maps to help guide
new land allocations within the plan to areas at low risk of flooding, via a sequential test.
345.
Where there may be higher risks of flooding of new land allocations because the detailed
modelling of watercourses has not been undertaken or parts of a site lie within higher flood
zones, a Level 2 Strategic Flood Risk Assessment has been undertaken. This applies to
Sites BC1, , BL1, BL2, BL3, HA1, KN1, KN2, ME1, SO2, UK1 and UK2. This more detailed
assessment defines flood zones where relevant and provides guidance on the parts of sites
where development should and should not take place, as well as considering opportunities
for enhancement. The Level 2 Strategic Flood Risk Assessment has been used to inform the
concept masterplans and Site Policies in the relevant Settlement chapters.
346.
For new developments at risk of flooding, a site specific flood risk assessment must be
undertaken which demonstrates that the development will be safe for its lifetime, in
accordance with the NPPF.
347.
New development sites must be resistant and resilient to flooding, to accord with the NPPF.
Drainage systems must be designed so that flooding does not occur on any part of or off the
site in a 1 to 30 year rainfall event, unless an area is designated to hold or convey water as
part of the design, or in any part of a building or plant susceptible to water in a 1 to 100 year
rainfall event. The design of the site should ensure that flows resulting from events in excess
of a 1 to 100 year rainfall event, are managed so as to minimise the risks to people and
property, including flows from adjacent land where relevant. Finished floor levels must be no
lower than 300mm above average surrounding ground level. Where at risk from fluvial
flooding, finished floor levels must be a minimum of 600mm above the 1 to 100 year plus
climate change flood level, or for minor development where detailed modelling of the latest
climate change allowances has not been undertaken, no lower than 600mm above the 1 in
1000 year flood level. Where relevant, the layout of buildings should direct the most
vulnerable elements of a development to the areas of lowest risk, including access routes
wherever possible.
348.
Where development results in the loss of flood plain storage, compensatory storage should
be provided on a level for level and volume for volume basis. Mitigation measures should be
provided up to the 1 in 100 (1% AEP) plus climate change fluvial flood event including the
requirement for safe access and egress.
349.
Across the Borough 2,000 existing properties are considered to be at risk of fluvial flooding.
For surface water flooding, there are approximately 1,500 properties across the Borough
considered to be within a 1 in 30 year flood outline and 4,500 properties within the 1 in 100
year flood outline. In order to increase resilience, where developments are proposed that
increase the size of buildings within areas identified to be at risk from flooding then
appropriate individual property level resilience measures should be incorporated in order to
reduce the impact and associated costs of repair of homes and buildings along with misery
and disruption caused by flooding to families and businesses.
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