Preliminary Flood Risk Assessment 2011

The European Floods Directive (Directive 2007/60/EC on the assessment and management of flood risks) places duties on the Environment Agency and local authorities to prepare flood risk assessments.

The Preliminary Flood Risk Assessment (PFRA) is a requirement of the Flood Risk Regulations (2009) and also covers a number of principles of the Flood and Water Management Act (2010). 

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Under the Act, Cornwall Council is designated as Lead Local Flood Authority (LLFA) within the administrative area of Cornwall.  Under the Regulations, all LLFAs in England and Wales were required to submit a PFRA to the Environment Agency by 22 June 2011.

The PFRA is a high level screening exercise to locate areas in which the risk of local flooding is significant and warrants further examination.  The scope of the PFRA is to consider past flooding and possible future flooding from local flood sources, most specifically from surface water and for flooding from Ordinary Watercourses.  The PFRA does not address flooding from designated Main Rivers or from the sea unless there are interactions with local sources of risk.  The PFRA identifies priority local flood risk communities within the LLFA’s jurisdiction.  This is done by considering both past flooding and potential future flooding.  The preparation of the PFRA is also the first step toward the development of Cornwall’s local flood risk strategy, providing an evidence base and identification and prioritisation of local flood risk areas.

The essence of the PFRA is fairly prescriptive, with guidance as to its content laid out by the Environment Agency, but the substance of the PFRA should reflect local issues and characteristics.  The PFRA consists of a report and associated spreadsheets.  The spreadsheets are designed by the Environment Agency so that the information submitted from all LLFAs can be readily assimilated and collated for submission by the Environment Agency to the European Commission.  These spreadsheets are provided as Annexes 1, 2, 3 and 4 of the PFRA .  The preparation of a PFRA is just one of several responsibilities of LLFAs under the new legislation. The PFRA Report provides a brief overview of other responsibilities Cornwall Council is obliged to fulfil under its role as a LLFA.

The PFRA sets out arrangements for partnership working and data sharing, particularly between the Council, the Environment Agency and South West Water. 

The PFRA considers the types of local flooding that are prevalent within Cornwall.  It reviews historic flooding and a chronology of major flood events in Cornwall is provided as Annex 5 of the PFRA.

Potential future flooding and its consequences are considered, mainly based on surface water flood risk using a methodology and flood risk indicators set out by the Environment Agency.  A detailed analysis of potential surface water flood risk in Cornwall is provided as Annex 6 of the PFRA.  This analysis indicates that there are no Indicative Flood Risk Areas in Cornwall, as defined by the national threshold of 30,000 people at risk of surface water flooding and no Proposed Flood Risk Areas as defined within the guidelines are recommended.

A review of communities associated with existing flood risks is carried out and reported within Annex 7 of the PFRA.  These are used to identify locations where flooding is locally an issue but fall below the national Indicative Flood Risk Area thresholds.  Further work will be undertaken to address local flood risk in these priority locations as part of the Local Flood Risk Management Strategy.

The Flood Risk Regulations set out a rolling programme based on a 6 year cycle.  The PFRA will need to be updated and resubmitted in 2017.

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These Preliminary Assessment Report Spreadsheets are based on set templates for submission to the Environment Agency and Europe.

The past floods data in Annex 1 is also discussed in Chapter 4.2 of the main text.

The future floods data in Annex 2 is also discussed in Chapter 5 of the main text.

No Indicative Flood Risk Areas are identified for Cornwall and therefore none have been recorded in Annex 3.

This has been provided by the Environment Agency to aid in the reviewing of PFRA submissions.

This provides a compilation of past flood events and episodes that have happened in Cornwall.

This details the analysis of surface water flood risk used to identify any Indicative or Proposed Flood Risk Areas and assesses the risks to local communities associated with surface water flooding.