Flood Risk Assessments for Planning Applications in Argyll & Bute, Highland and throughout Scotland
Regulatory Requirements for a Flood Risk Assessment
Fluvial, pluvial and coastal flood risk assessments are needed when building in or near designated flood risk zones in Scotland. The request for these comea from the Scottish Environment Protection Agency (SEPA) and/or the Local Authority's Flood Risk Management Team.
This is because the planning process requires that it be demonstrated that land proposed to be developed can be done so with an acceptable risk of flooding and that any works needed to manage flood risk are sustainable over the likely life of the development.
National Planning Policy Requirements
Policy 22 of National Planning Framework 4 (adopted in February 2023) covers flood risk. This states that:
a) Development proposals at risk of flooding or in a flood risk area will only be supported if they are for:
i. essential infrastructure where the location is required for operational reasons;
ii. water compatible uses;
iii. redevelopment of an existing building or site for an equal or less vulnerable use; and
iv. redevelopment of previously used sites in built up areas where the LDP (Local Development Plan) has identified a need to bring these into positive use and where proposals demonstrate that long-term safety and resilience can be secured in accordance with relevant SEPA advice.
The policy goes on to state that protection offered by an existing formal flood protection scheme or one under construction can be taken into account when determining flood risk. In such cases, it will be demonstrated by the applicant that:
• all risks of flooding are understood and addressed;
• there is no reduction in floodplain capacity, increased risk for others, or a need for future flood protection schemes;
• the development remains safe and operational during floods;
• flood resistant and resilient materials and construction methods are used; and
• future adaptations can be made to accommodate the effects of climate change.
Additionally, for development proposals meeting criteria part iv), where flood risk is managed at the site rather than avoided these will also require:
• the first occupied/utilised floor, and the underside of the development if relevant, to be above the flood risk level and have an additional allowance for freeboard; and
• that the proposal does not create an island of development and that safe access/ egress can be achieved.
b) Small scale extensions and alterations to existing buildings will only be supported where they will not significantly increase flood risk.
c) Development proposals will:
i. not increase the risk of surface water flooding to others, or itself be at risk.
ii. manage all rain and surface water through sustainable urban drainage systems (SUDS), which should form part of and integrate with proposed and existing bluegreen infrastructure. All proposals should presume no surface water connection to the combined sewer; and
iii. seek to minimise the area of impermeable surface.
d) Development proposals will be supported if they can be connected to the public water mains. If connection is not feasible, the applicant will need to demonstrate that water for drinking water purposes will be sourced from a sustainable water source that is resilient to periods of water scarcity.
e) Development proposals which create, expand or enhance opportunities for natural flood risk management, including blue and green infrastructure, will be supported.
Local Authority Requirements
Flood risk is referred to in Local Development Plans. These state that development proposals should avoid areas susceptible to flooding and promote sustainable flood management.
Scottish Environment Protection Agency
SEPA provides guidance on flood risk assessment to practitioners and Local Authorities through a series of guidance documents, namely:
• Flood Risk and Land Use Vulnerability Guidance.
• Climate change allowances for flood risk assessment in land use planning.
• Technical Flood Risk Guidance for Stakeholders.
Our Experience
TransTech has been carrying out all forms of flood risk assessment work since 2006 for a wide range of development proposals.
For sites where the landform and/or channel geometry clearly indicates no risk a site investigation and desk study usually provides evidence that the development does not lie within a functional floodplain.
NB: We no longer provide hydraulic modelling services for sites at risk of fluvial and pluvial flooding but can recommend consultants that can provide these services.
Comprehensive Reporting
A report is then produced with our findings which includes the assessment of the effects of climate change on flood risk at the site in question, as required in National Planning Framework 4.
Why Choose TransTech?
At TransTech, we pride ourselves on delivering reliable, high-quality flood risk services. With nearly two decades of experience, we’ve worked with clients across Scotland and the UK, providing tailored solutions for projects of all sizes. Our team is passionate about ensuring developments remain on track and compliant with regulations.
Contact Us Today
If you’d like to inform us of the flood risk assessment you’ve been asked to undertake or learn more about our services, please contact garret@transtechltd.com, 07810 746470. Our team is happy to provide advice and outline the best solutions for your project.
