Sources of flooding on floodplains of the tidal Thames

The Thames Estuary 2100 (TE2100) project requires an assessment of flood risk for present day and future scenarios for the tidal Thames floodplains, to provide a basis for planning flood risk management over the next 100 years and beyond.

To do this it is first necessary to understand the causes of flooding. The main potential sources of flooding include the surge tides on the tidal Thames, and fluvial flooding from the Thames, tributaries, land drainage systems and urban drainage systems. Flooding is affected by the operation of moveable gates including the Thames Barrier and barriers on other tributaries.

The paper describes the sources of flooding, the ways in which they interact and the effects that they have on flood levels. The flood management system on the tidal Thames is described, and the impacts of failure of elements of the system are considered.

Extreme sea levels and fluvial flows are expected to increase in the future, and the main implications for flood management on the Thames are summarised.