Evidence base and monitoring

The Strategic Flood Risk Assessment (SFRA) is a critical evidence base document which underpins the Local Plan.  The SFRA consists of two elements:

• Level 1 – Overarching District-level assessment, applying existing published (secondary) data to establish whether new development can be allocated outside high and medium flood risk areas.
• Level 2 – More detailed bespoke site-specific flood risk assessment (e.g. for an individual settlement), involving primary data collection and modelling regarding probability, depths, velocity rates and duration of flooding.  A Level 2 SFRA is required where the Level 1 assessment shows that land outside low flood risk areas cannot appropriately accommodate all the necessary development.

Level 1 SFRA

The previous Level 1 SFRA was completed in August 2011. The Environment Agency (EA) formally advised the Council about the likely need to undertake detailed Level 2 SFRA work for certain sites/ locations, in a letter dated 26 September 2011.  It has been necessary to update the previous Level 1 SFRA, to support the East Northamptonshire Local Plan Part 2.

Work to update the Level 1 SFRA was begun in 2018.  Further engagement with statutory consultees (e.g. Environment Agency; Northamptonshire County Council (Lead Local Flood Authority); and Anglian Water) was undertaken during autumn 2019, with the document finalised in February 2020.  The updated Level 1 SFRA consists of the following:

• Main SFRA report, incorporating appendices 1, 2 and 5
• Appendix 3a – Site assessment
• Appendix 3b – Site assessment – map index
• Appendix 4a – EA preliminary SFRA review, 2 October 2018
• Appendix 4b – Irthlingborough Flood Zone map, October 2018
• Appendix 4c – Irthlingborough Flood Zone 3b map, October 2018
• Appendix 4d – Conalgen Enterprises SA representation regarding Local Plan Part 2, 13 December 2018
• Appendix 4e – Correspondence on behalf of Conalgen Enterpreises SA, 17 September 2019
• Annex A – SFRA Level 1 strategic maps
• Annex B – SFRA Level 1 site maps

The final draft Level 1 SFRA was circulated to the Environment Agency in January 2020.  It was signed off by the Environment Agency on 7 February 2020.

Level 2 SFRA

Following on from the 2011 SFRA, a more detailed Level 2 SFRA was undertaken, examining specific potential development sites around Rushden and Irthlingborough. This work was completed in November 2012. The EA (response, 14 December 2012) has endorsed the Level 2 SFRA in respect of the assessment of sites at Rushden and Irthlingborough.

Level 2 SFRA Report and Appendices (November 2012):

• Level 2 SFRA Report
• Study Area
• Rushden Lakes
• Rushden Town Centre Sites
• Finedon Road Stream, Irthlingborough
• Pluvial modelling

The detailed Level 2 SFRA remains pertinent with respect to identified sites at Rushden and Irthlingborough, and should be read in conjunction with the updated (2020) Level 1 SFRA.