Strategic Flood Risk Assessment

As a coastal town, consideration of flood risk plays an important role in development decisions in the Borough. In 2016 the local authorities that form the Partnership for South Hampshire (PfSH) produced a Strategic Flood Risk Assessment (SFRA). This work was carried out by the Eastern Solent Coastal Partnership The SFRA comes in two parts:

• A mapping database and;   (We are aware of an issue viewing the map layers on the SFRA mapping website when using the browser Google Chrome. If you encounter any issues please try another browser like Firefox, Opera or Microsoft Edge.)

• The Strategic Flood Risk Assessment report (PDF, 162 KB).

The mapping database shows coastal flooding, surface water flooding and the potential impact of climate change.

The final report summarises the key findings of the SFRA and is tailored for:

• The specific flood risk found in each Local Planning Authority area;
• Relating national policy to specific SFRA information and data; and
• Providing guidance on the requirements of site-specific FRAs.

Important Notice

Since the 2016 PfSH SFRA mapping dataset was produced, national Climate Change Allowances have been updated to take account of the latest climate change projections (UKCP18). These projections build on the previous set of projections (UKCP09) to provide the most up to date assessment of how the climate may change over the 21^st Century.

PfSH are currently preparing a new SFRA which takes into account these latest Climate Change Allowances.

The Council has published in PDF format the mapping outputs from the draft PfSH SFRA Level 1 and Level 2 which can be viewed on the Council's under 'Flood Risk and Coastal Erosion' section.

However as the SFRA is still at a draft stage, the mapping is not yet available in an interactive format to inform the preparation of site-specific FRAs.

For detailed site-specific Flood Risk Assessments (FRA), site promoters and applicants will need to obtain the most up to date data to support FRAs. The Environment Agency have a number of products available including Product 4 which is generally used for the majority of average sized developments and Product 6 where applicants need to obtain the detailed modelling required to make adjustments for larger, more complex development proposals.  Further information relating to each product and how they can be obtained can be found at: www.gov.uk/guidance/flood-risk-assessment-for-planning-applications

The Environment Agency are currently in the process of updating these products to incorporate the UKCP18 climate change allowances. Until both this programme of work has been completed and the PfSH SFRA Level 1 interactive mapping layers are available; applicants are advised to request FRA Product 4 for present day flood levels from the Environment Agency and add the appropriate climate change allowances using the data from 'Flood risk assessments: climate change allowances' which is available at: www.gov.uk/guidance/flood-risk-assessments-climate-change-allowances

Surface Water Maps
Flooding from surface water is an important flood risk consideration. The Environment Agency has published its National Risk of Flooding from Surface Water (RoFSW) mapping on the Check Your Long Term Flood Risk (CYLTFR) since 2013 this is available to view at: www.gov.uk/check-long-term-flood-risk

Please note the results from the site are an indicator of an area's flood risk, particularly the likelihood of surface water flooding. It is not suitable for identifying whether an individual property will flood. It does not include the flood risk from sources such as blocked drains and burst pipes.