EA Release Flooding Scenarios Report

LTIS Flooding Scenarios_64071

The Environment Agency has published its long term planning for flood investment, the Long Term Investment Scenarios 2019 (LTIS 2019).

LTIS 2019 replaces the current LTIS 2014 report and brings together new analysis and understanding of long-term investment scenarios for flood and coastal erosion risk management (FCERM).

LTIS is an evidence report for informing the flood and coastal risk management sector, government departments and the insurance industry. LTIS 2019 is already being used as part of the evidence base for the FCERM 2100 Strategy which will be published for consultation in May 2019. It is also informing the evidence for the National Infrastructure Commission’s Resilience Study and the Climate Change Committee’s forthcoming climate change risk assessment.

LTIS 2019 forms the baseline groundwork for future investment thinking. 

Main Findings

The Met Office published UK Climate Projections 2018 (UKCP18) in November 2018.

LTIS sets out the challenges of managing flood and coastal erosion risk in the face of:

  • asset deterioration
  • climate change
  • a growing population

This report describes:

  • future risks
  • future opportunities
  • the implications for long-term investment levels

Calls for Increased Investment

The evidence from the new scenarios show that the new overall economic optimum level of investment is a long term average of £1bn, compared to £860 million from the previous scenarios published in 2014.

The increase in estimated investment is due to the range across medium and high climate change scenarios and an increase in recognition of the investment needed to manage surface water.


LTIS 2019 found that infrastructure at risk from surface water flooding would impact 60% of properties in England.

The report also suggests that assets would be left to degrade due to the strict economic criteria of assessing cost effectiveness of maintenance.

The importance of current and future planning policy in relation to FCERM in the long-term was also highlighted in the report due to the number of properties situated in the floodplain is expected to increase by 50% over the next 50 years.

Potential Impacts

One main issue in the LTIS 2019 report is that it only considers the value of managing and maintaining existing assets and watercourses as a fixed cost and so assumes that the capacity of watercourses are maintained at current levels. This is a significant assumption, given that current variations in funding for asset maintenance, and potential climate impacts, are likely to increase scour and silt deposition in our watercourses, increasing channel maintenance and costs just to maintain capacity. It will be important to consider how and where channel maintenance can be a useful adaptation tool under future scenarios and the investment required.

Visualisation Tool

EA have also developed a fully working prototype for an interactive web-based visualization tool that draws on the 8,000 scenario outputs from some of the national LTIS outputs.  The LTIS Visualizer allows you to see the effects of your national investment choices for different FCERM options, and find the mix of national investments that gives the best value for money.

Further Information

You can view the LTIS 2019 key findings here and read the accompanying gov.uk news story here.