Coastal adaptation options to protect railway infrastructure in Dawlish, South Devon Coast,UK

Description

The South Devon Coast, located in the South West of England is an important area for tourism; it includes sites with heritage and nature conservation, and urban areas. In addition, it includes some important railway infrastructure connecting the South West of England to larger cities such as London. This study focuses at the coastal area stretching from the town of Teignmouth, including the town of Dawlish, through to Dawlish Warren, covering a length of about 10 km. Provision of housing/residential areas, infrastructure and tourism, and heritage and nature conservation are already under pressure from coastal erosion, and sea and river flooding (e.g. the town of Teignmouth is located at the mouth of the river Teign), a situation which will be exacerbated by climate change.

The extreme storm events at the coast at Dawlish (February 2014), which severely damaged the sea wall and the railway, increased the risk of flooding for the houses behind the sea wall, and disconnected the railway connection of the southwest of England to the rest of the country, demonstrating the vulnerability of the area to extreme events and future climate impacts. Moreover, due to the geomorphological setting of rocky/cliff shores, options for managed flood plains, dikes, or managed realignment of the coast are limited, which presents further challenges when considering and developing climate change adaptation pathways. The seawall and railway tracks are owned and managed by a government-owned company - Network Rail -, the train services are run by a private company, the local authorities do not have the resources and capacity to make major decisions around this part of the coast, and the national authorities claim adaptation in this area is a matter of the local authorities.

The discussion about how to adapt this coastal area to current and expected challenges, after the severe storm events in February 2014 focused on the railway connection only, and did not link it to climate change impacts and climate change adaptation more generally. Several options to reduce the vulnerability of the railway to current climate risks were considered, broadly they are:

1) Business-as-usual. This option entails maintaining the existing sea defences at Dawlish and conducting repairs to damage to the rail infrastructure, cliffs and sea wall from storm events as and when they occur;

2) Strengthen the existing sea defences. This would involve strengthening and heightening the sea wall, stabilising the cliffs through wire netting and bolting, and measures to mitigate the erosion of beach material (e.g. improved groynes);

3) Reroute the railway inland away from the vulnerable Dawlish coast.

Reference information