Overview
The Ipswich Strategic Flood Risk Assessment 2020 comprises a main report and appendices which refer to potential sources of flooding considered likely to affect Ipswich. Ipswich Borough Council's new Level 2 Strategic Flood Risk Assessment was published in October 2020. This supersedes the Level 2 SFRA prepared in 2011. The Ipswich Strategic Flood Risk Assessment 2020 can be downloaded below.
- Ipswich Strategic Flood Risk Assessment 2020 (including Appendix B) (PDF)
- Ipswich Strategic Flood Risk Assessment 2020 Appendices A Mapping, C SWMP Extracts, D Speed of Onset and Duration, and E Guidance on Flood Plans for New Buildings (PDF)
- Ipswich Strategic Flood Risk Assessment 2020 Appendix F Site Sheets (PDF)
- Ipswich Strategic Flood Risk Assessment 2020 Appendix G Breach Modelling (PDF)
- Flood Risk Sequential and Exception Test Statement (PDF)
The Development and Flood Risk Supplementary Planning Document ('SPD') was updated in July 2022 to reflect the new Strategic Flood Risk Assessment 2020. View the Development and Flood Risk SPD 2022.
New Data – Ipswich Strategic Flood Risk Assessment Update Statement
Since the Ipswich Strategic Flood Risk Assessment (SFRA) was published in October 2020, there have been data and guidance changes at a national level. These are listed below, and their local implications are examined.
New Climate Change Allowances – Peak River Flow
In July 2021, the Environment Agency updated the climate change allowances that should be applied to peak river flows. For the River Gipping, the climate change allowances that need to be considered by the local planning authority have reduced slightly. As a result, there are sections of the SFRA Report that are now out of date, and assessments made in the SFRA that are more conservative than they need to be to comply with national planning policy. The updated climate change allowances will be reflected in the next review of the SFRA. In the meantime, applicants are directed to the allowances published nationally and should note that the SFRA represents a more cautious position.
New Climate Change Allowances - Peak Rainfall
In May 2022, the guidance was also updated with peak rainfall allowances. The allowances are provided by management catchments instead of at a national scale (for England). Peak rainfall allowances are provided for 1% annual exceedance probability (AEP) events and for 3.3% AEP events, and for 2 epochs rather than 3. The guidance on how to apply peak rainfall allowances has changed, using the central allowance for development with a lifetime up to 2100 and the upper end allowance for development with a lifetime from 2100 to 2125. The updated peak rainfall allowances will be reflected in the next review of the SFRA. In the meantime, applicants are directed to the allowances published nationally Climate change allowances for peak rainfall in England.
Updated Planning Practice Guidance on Flood Risk and Coastal Change
In August 2022, the Government published updated Planning Practice Guidance on Flood Risk and Coastal Change. Applicants will need to check compliance with the National Planning Policy Framework and Planning Practice Guidance in preparing a site-based Flood Risk Assessment or Drainage Strategy. The Council will update the SFRA and Development and Flood Risk Supplementary Planning Document to reflect the new information in due course.
View other useful documents about drainage in Ipswich.
Ipswich Strategic Flood Risk Assessment 2011 (Superseded)
The Strategic Flood Risk Assessment informed the production of the Development and Flood Risk Supplementary Planning Document (PDF) ('SPD') in 2013 (and updated in 2016) which provided specific guidance to developers including a framework of requirements for "safe" development in the flood plain. The 2022 Development and Flood Risk SPD (see above) supersedes the earlier Development and Flood Risk versions.
You can download the superseded 2011 Strategic Flood Risk Assessment (SFRA) and its appendices in PDF format using the links below: