TE2100: managing flood risk on the Thames Estuary

Flood risk on the Thames Estuary is increasing. Climate change is causing increases in sea level and river flows, and new development is taking place on the floodplain.  Recent and ongoing developments include the Olympic Park, Canary Wharf and the Thames Gateway Port.

In addition, the major flood management system for the tidal Thames is deteriorating. Many of the defences were built following the 1953 floods, and will reach the end of their design lives during the next 50 years. The system includes the Thames Barrier, over 300 km of fixed defences and numerous smaller structures. To plan for the expected future changes in flood risk and the need to upgrade the flood management system, the Environment Agency has undertaken the Thames Estuary 2100 project (TE2100) in which a plan was developed for managing flood risk on the Thames estuary over the next 100 years.

We undertook a range of studies to improve the understanding of the estuary including flood risk, sediment transport and estuary morphology. We assessed the joint probability of flooding from different sources and developed a flood risk model that takes account of the condition and deterioration of the defences.

Working with the Environment Agency’s in-house team, HR Wallingford then developed flood risk management options for a range of different climate change scenarios. Each option includes a sequence of interventions at different times throughout the century, depending on the rate of climate change.

We developed a programme of studies to assess the feasibility of the options. Studies undertaken by HR Wallingford during this phase including flood modelling to determine flood defence levels, design of habitat creation areas, outline designs of potential new barriers and barrages, and predictions of morphological change in the estuary. We used these results to refine the options and develop the final options for appraisal.

The selected option is a combination of improvements to the existing flood management system followed by a major improvement to the system later in the twenty-first century.  This will either include a new Thames Barrier or upgrading of the existing Thames Barrier. 

We then assisted the Environment Agency with public consultation and finalisation of the Plan during 2010 to 2012. The Plan was approved by the government in 2012 and is now being implemented. We produced a range of guidance and information documents to assist with the implementation of the Plan during the period 2012 to 2015.  We have also continued to advise on the requirements of the Plan for existing and planned developments along the Thames estuary.