Planning and flood risk
As the Local Planning Authority (LPA) we take decisions on planning applications, we are obliged to apply national planning policy around avoiding flood risks, and where this is not possible controlling, managing and mitigating remaining flood risks.
National planning policy, planning practice guidance and our local list of requirements define when a site-specific Flood Risk Assessment (FRA) should be prepared by applicants and submitted with their planning application.
It is important that an FRA takes account of all sources of flood risk that might affect a site. This includes flood risk from surface water and groundwater along with flood risks from tidal and fluvial sources. The FRA should also make allowances for climate change to help us understand future flood risks. In addition to the prevailing flood risk, we also expect applicants to consider and prioritise the use of sustainable drainage systems (SuDS). This is for the management of surface water runoff generated by the proposed development, and to reference these systems in their FRA.
Preparing Local Plans
In our planning role we are also responsible for preparing Local Plans for our area which set out strategic planning priorities. Details of the Local Plans relevant to Dorset can be found within the Planning, buildings and land section of our website. The Local Plans are supported by evidence including Strategic Flood Risk Assessments (SFRA).
As part of preparing the Dorset Council Local Plan we have prepared a new Level 1 Strategic Flood Risk Assessment which relates to the whole council area and Level 2 Strategic Flood Risk Assessment for Weymouth. We will also take account of the SFRA when making decisions on planning applications, and when relevant applicants should refer to these SFRA when preparing a Flood Risk Assessment for their planning applications.
Local communities can develop Neighbourhood Plans. A Neighbourhood Plan may set out planning policies for the local area but must still take account of, and be consistent with, national policy, planning practice guidance and adopted local plan policy. Once adopted, Neighbourhood Plans become part of the Local Development Framework and therefore must be considered when determining planning applications in that area.
Local communities must take account of flood risk when preparing neighbourhood plans, and as part of this apply the sequential and exception tests to the neighbourhood plan making process. It may be helpful to refer to our SFRA, as part of assessing flood risk, but local communities may also decide that they need to gather their own local evidence on flood risk.
Flood risk planning consultations
The Environment Agency is a statutory consultee on certain development proposals that are at risk of flooding from main rivers and the sea. There is standing advice on the Environment Agency's website which explains what proposals they want to be consulted on. This helps steer the applicant to the appropriate level of detail required for a Flood Risk Assessment (FRA).
In our role as Lead Local Flood Authority (LLFA), we will provide consultation responses to major developments. As part of the LLFA’s consultation response the LLFA will review the FRA to ensure that the applicant has considered flood risk from all local sources including surface water, groundwater and flooding from ordinary watercourses.
Surface water management proposal requirements
All major developments will require a surface water management proposal which may be incorporated within a Flood Risk Assessment. National Standards for sustainable drainage systems should be followed.
The LLFA are a statutory planning consultee for surface water management proposals on:
- major developments of ten or more houses and
- commercial development of floor space greater than 1000m2 or sites larger than 1Ha
We review and comment on the applicant’s surface water drainage strategy. Sufficient evidence should be submitted by the applicant in order to demonstrate that the proposed sustainable drainage system (SuDS) will be viable and can be delivered for the proposed development. Applicants should adopt the SuDS hierarchy when designing their drainage schemes and ensure that surface water flood risk will not be increased on or offsite as a result of a development.
For advice on what to submit please see our Surface Water Management Proposal Information Requirements.
If you require further advice please contact the Flood Risk Management Team.
Surface water management planning advice
We offer a charged service for providing detailed pre-planning advice which is provided through an agreement between ourselves and the Developer.
We encourage all applicants to discuss their proposal with us before submitting a planning application to our colleagues in the planning team. An awareness of local flooding mechanisms and expectations will result in a better chance of a successful outcome and help to speed up the decision-making process after submission.
See our planning advice for surface water management for further information and charging arrangements.