Airport proposal puts Thames habitat at risk

HR Wallingford conducted a preliminary assessment of a typical inner Thames Estuary proposal, located in the inner estuary at the Isle of Grain. Using its in-house hydrodynamic models of the Thames Estuary (developed in conjunction with the Port of London Authority and the Environment Agency), it assessed the potential effects of an airport on estuary tidal flow magnitude, directions and water level, and on wave propagation. This provided an initial indication of the scale of possible effects of an inner Thames Estuary airport on navigation, flood defence and estuary habitats.

A preliminary technical assessment concluded that an inner estuary airport would lead to profound changes in the wider estuary environment, probably of a scale not seen on the estuary for a century or more. For example, beyond the direct footprint of a scheme, HR Wallingford provisionally estimated that approximately 2,500ha of intertidal estuary habitat is indirectly at risk of change from the assessed scheme. With refinements to the airport platform, it should be possible to reduce the scale of changes to the estuary, but it will not be possible to eliminate them altogether.

HR Wallingford’s submission was prepared and submitted on a pro bono and independent basis, to support an evidence-based review of airport options. HR Wallingford’s full response to the Call for Evidence can be download from its ePrints repository or from the Airports Commission.

In response to the publication of the Airports Commission’s consultation note on environmental impacts, Dr Mike Dearnaley, director at HR Wallingford said: “We are delighted that the Airports Commission has found our evidence of use for their feasibility study. With our long track record and specialist environmental expertise for the Thames, we hope to continue to contribute to the examination of airport proposals in the estuary.”

By Larz Bourne