skip to content

Cambridge Institute for Sustainability Leadership (CISL)

1 August 2023 - The University of Cambridge Institute for Sustainability Leadership’s (CISL) ClimateWise has published a new report on planning decisions, adaptive capacity and insurability.

Planning decisions, adaptive capacity and insurability

Read the report


This study aims to assess whether planning practice delivers protection from flooding for 100 years. If there are conditions where it does not, will these planning failures also lead to withdrawal of insurance and leave properties unprotected from flood risk? Flooding is the greatest natural disaster risk in the UK, with an estimated one in six properties in England and Wales, one in 11 properties in Scotland and one in 34 properties in Northern Ireland now at risk of flooding.

Somerset is one of the UK regions at significant risk from flooding. Somerset also has a range of types of flood risk representative of the wider UK risk. Despite the fact that planners are asked to ensure properties are safe from flooding for 100 years, the planning systems in Somerset are not always able to provide such protection for new development. Where this fails, insurance has a critical role to play to provide a safety net.

This project considered two different planning regulatory frameworks for flood risk: fluvial flood risk and surface water flood risk. We explored whether the regulatory framework of these two categories affected the probability of flood protection and insurability. The research also considered how flood risk outcomes were affected by the adaptive capacity of planners, planning enforcers and developers affected flood risk protection at property level.

Since the study has been conducted, the Government announced it planned to introduce the long-delayed Schedule 3 of the Flood and Water Management Act 2010 to mandate the use of Sustainable Drainage Systems (SuDS) in new developments in England. The intent is to attempt to address the issues highlighted in the study. During the development of the report, the details supporting this intent had not been settled. Therefore, this report offers a reminder of the factors that drive exposure to flood risk in new developments and the consequences of not fully addressing these risks.  

Citing this report

University of Cambridge Institute for Sustainability Leadership (CISL). (2023). Planning decisions, adaptive capacity and insurability: Findings from a case study of flooding in Somerset, UK. Cambridge, UK: University of Cambridge Institute for Sustainability Leadership.

Read quotes about the report here.


Published: August 2023 

Authors and acknowledgements

The lead authors of this report were Nick Pyatt of Climate Sense and John Ward of Pengwern Associates, with project management assistance from CISL’s ClimateWise and JBA Risk Management.

The authors are grateful for the support of Somerset Rivers Authority, Somerset County Council, Somerset Lead Local Flood Authority, Sedgemoor District Council, Mendip District Council, The Environment Agency, Calm Engineering, JBA Consulting and Rheos Environmental Consulting Limited. We are also very grateful for the contribution of ClimateWise members, particularly ABI and Flood Re. The project was funded by the ClimateWise membership and the Place-based Climate Action Network (PCAN).


The opinions expressed here are those of the authors and do not represent an official position of CISL or any of its individual business partners or clients.


Copyright © 2023 University of Cambridge Institute for Sustainability Leadership (CISL).