Appeal 3341233

The appeal is dismissed.

The Council has concluded that the proposal does not constitute inappropriate development in the Green Belt as it can be considered as an exception under paragraph 154 c) of the National Planning Policy Framework (the Framework) which allows for the extension of existing buildings provided that it does not result in disproportionate additions over and above the size of the original building. The appellant does not disagree and having regard to the information provided I concur with this finding.

The main issue is therefore the impact on flood risk.

The appeal site lies within [name] 2 and 3 which are defined as having medium and high risk of flooding respectively. Paragraph 173 of the Framework states that where appropriate, applications should be supported by a site-specific flood-risk assessment (FRA). Related footnote 59 clarifies that a site-specific FRA should be provided for all development in [name] 2 and

Framework paragraph 173 goes on to set out that development should only be allowed in areas at risk of flooding in the light of such an assessment subject to demonstrating a number of criteria.

The appellant refers to a ‘flood risk assessment’ having been submitted with the original application although this is by reference to the submitted plans (in particular sheet no. 4) and details on it which indicate how the surface water would be dealt with via drainage grills, downpipes and gutter drains connected to the watercress bed which then subsequently discharges into the river. However, this information relates to the surface water drainage scheme rather than a site-specific flood risk assessment as required by the Framework and thus only addresses one of the criteria in Framework paragraph 173.

The National Planning Policy Guidance clarifies that a site-specific FRA assesses the flood risk to and from a development site and should demonstrate to the decision-maker how flood risk will be managed now and over the development’s lifetime, taking climate change into account and with regard to the vulnerability of its users. It goes on to set out the objectives of the site-specific FRA and refers to further guidance regarding its scope.

Whilst the FRA should be appropriate to the scale, nature and location of the development, the information provided by the appellant does not provide any detailed assessment of the flood risk including whether the development is likely to be affected by current or future flooding from any source or whether it will increase the risk of flooding elsewhere. Nor does it provide any technical detail of the amount of surface water that may arise as a result of this and the development itself. As such, it is not possible to conclude whether the details of surface water drainage scheme would be adequate or suitable. Therefore, the level of detail that is required in order to meet the stated objectives of the FRA is inadequate.

The appellant contends that the level of information provided is similar to that provided to support a previous application relating to an extension to the dwelling. I have very limited details of that scheme which was for a different form of development anyway. Concerns are also expressed regarding the way in which the application was dealt with by the Council and lack of clear guidance on what was required. However, this is a matter between the appeal parties which does not alter my findings above which are based on the information before me.

Therefore, it fails to accord with the Framework and is not acceptable from a flood risk perspective. It also fails to demonstrate compliance with Policy CS31 of the Dacorum Borough Core Strategy (2013) which seeks to avoid development within flood zones 2 and 3 unless for a compatible use and unless accompanied by an FRA which demonstrates that it is suitable and does not increase flood risk.

For the above reasons I conclude that the appeal should be dismissed.