Flood Risk |
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4.1.51 Scottish Executive
policy on flooding Scottish Planning Policy (SPP) 7 – Planning and Flooding, addresses a number of problems which
flooding can cause, including the emphasis that flooding is a material
consideration in planning decisions and the application of the precautionary
principle. It states that development of an area which is exposed to frequent
or extensive flooding is likely to be unsustainable and should be avoided.
Local plans are required to indicate areas where a degree of flood risk exists
and define areas where new development should be avoided.
4.1.52 The Structure Plan (see
para 9.3 to 9.5) in Strategic Policy 9B (viii) requires that development avoids
areas that are liable to flooding and presumes against developments which will
have an adverse effect upon flood plain areas. The Joint Committee are also
seeking to agree standards for acceptable flood return periods.
4.1.53 A hydrological study
was undertaken of the River Kelvin river system which has resulted in the implementation of a Flood Defence Scheme. This has been designed as a minimum to protect existing built up areas from
the effects of a predicted “100 year flood event”. In the majority of areas, the defence scheme has actually been designed to more than accommodate
the 1994 flood which approximated to a 200 year event. The Council will also
take into account further flood risk mapping which is expected to be undertaken
during the life of this Plan.
4.1.54 The proposals map gives
an indication of areas known to have flooded or predicted to be at risk of
flooding. More detailed maps are available for
inspection at the council offices. There
may be other flood risk areas which have yet to be identified and in the
meantime the Council will, by applying the precautionary principle, continue to
take flood risk into account in dealing with all planning applications, in
accordance with SPP 7. The Council will, where appropriate, require development
proposals within these flood risk areas to be accompanied by a Flood Risk
Assessment. Arrangements for the implementation of flood alleviation measures
together with measures for maintenance and Sustainable Urban Drainage Systems
for new development to the satisfaction of the council will form part of any
relevant planning consent.
4.1.55 In applying acceptable
return periods, consistency is sought across the Structure Plan area and indeed
the whole country. To this end, return periods as contained in policy DQ 13B
are based on the ‘Risk Framework’ as contained in SPP 7.
4.1.56 Recent research published by the Scottish Executive “Climate
change: a review of levels of protection offered by flood protection schemes”
tentatively suggests that design levels of flood protection schemes should take
into account climate change predictions. Therefore, to take into account
climate change to 2050, a 20% factor should be added to determine the flood
flow quantities, unless alternative magnitudes are submitted to the
satisfaction of the Council. An allowance for freeboard will be required in
specific local circumstances, for example where wave action or water turbulence
is likely to occur, or where the accuracy of available data is not robust.
4.1.57 The Council will
consult with the Scottish Environmental Protection Agency on any planning
application within the flood risk areas or where it considers the nature of the
proposals are likely to have a potential impact on flood risk elsewhere.
|
DQ 13A
Flood defence scheme The Council has completed a strategic flood defence
scheme at the Kelvin, Luggie and Glazert river systems and will continue to
promote flood defence schemes where appropriate. |
DQ
13B Flood Risk
When assessing any proposed
development the Council will take account of the potential for flooding.
Development of an area which is known to be exposed to frequent or extensive
flooding is likely to be unsustainable and should be avoided.
The storage capacity of floodplains will be
safeguarded and flood alleviation measures should not lead to a loss of flood
water storage capacity.
In assessing the level of flood risk the Council will
have particular regard to:
a. the Proposals Map which shows areas known to
have flooded or predicted to be at risk of flooding;
b. areas where a degree of flood risk may exist
e.g. within 50 metres of flood risk areas, water courses, culverts,
lochs or ponds; or
c. where a
proposed development involves the construction, diversion or culverting of a
watercourse (see DQ 12).
The Council will consult the Scottish Environment
Protection Agency (SEPA) on flood risk with regard to all new development
proposals within the above areas.
Development proposals within these risk areas
will require to be accompanied by a ‘flood risk assessment’. If an unacceptable
flood risk cannot be managed to the satisfaction of the Council, the Council
will consider this justification to refuse planning permission. It should be
noted that flood risk assessment extends not only to the site of the actual
development, but also the effect which the development could have on
neighbouring or other potentially affected areas within the wider catchment.
Therefore, development should not have an adverse effect upon flood plains or
other flood attenuation areas.
The Risk Framework contained within the SPP 7
summarises the probabilities of flooding in three categories, the areas they
delineate and the appropriate planning responses. The probabilities are based
on:
Little or
no risk area: less
than 1:1000 annual probability (<0.1%)
Low to
medium risk area: 1:1000
– 1:200 annual probability (0.1% - 0.5%)
Medium to
high risk area: 1:200
or greater annual probability (>0.5%)
The little or no risk category represents the outer
limit to the area of concern for extreme flood events and thus, there are no
constraints due to flooding.
In the low to medium risk category, most development
is considered suitable unless local conditions indicate otherwise. However, a
flood risk assessment may be required at the upper end of the probability
range, i.e. close to 0.5%. These areas are generally not suitable for essential
civil infrastructure such as hospitals, fire stations, emergency depots etc.
which require to operate at times of flooding.
Areas in the medium to high risk category are
generally not suitable for essential civil infrastructure. Brownfield sites
that are protected by a strategic flood prevention scheme may include
opportunities for residential, institutional, commercial and industrial
development within the existing built-up areas. Sites that are not protected by
the strategic flood prevention schemes are not suitable for new development,
with the exception of locations being essential for operational reasons. In
such circumstances, measures for flood alleviation are likely to be required.
Subject to this policy, development which has been
subject to a flood risk assessment will only be permitted where the following
requirements are met:
a) the
results of the assessment have been fully taken into account in the design and
layout of the development, and
b) new
flood prevention schemes will not be permitted, rather alleviation measures
(such as landraising and underbuilding) should be used as appropriate subject
to:
i)
satisfactory maintenance measures being in place, and
ii) compensatory water storage being
provided.