Pawlett Hams realignment

This is an Environment Agency scheme to improve flood defences along the eastern bank of the River Parrett. The purpose of the scheme was to protect approximately 1200ha of low-lying agricultural land on Pawlett Hams and Pawlett Level. The history of flooding in this area, included severe inundations in 1609, 1798, 1903, 1936, and most recently in December 1981 when flooding occurred some 3-4km inland. Initially it was envisaged that flood defences would be maintained along the existing line. However, changing priorities led to other options being investigated, including several with a measure of managed retreat. Five options were examined, ranging from 'do nothing' to a full retreat to Pawlett Hill. Having carried out cost-benefit analyses, the favoured option was one that included construction of 1.4km of sea-wall set back from the old line by about 40m, leading to approximately 4.8ha of agricultural land being opened up to inundation by seawater.

Colonisation of this area was monitored between 1994 and 1997 (Leach et al. in prep) and within three years Puccinellia maritima and Suaeda maritima was present throughout the area, along with Spergularia marina, S. media and Parapholis strigosa at higher elevations (6.2-6.7m above Ordnance Datum (AOD) and Salicornia europaea agg. mainly at lower elevations (5.7-6.0m AOD).

References

Leach, S., White, L., Moodie, S.D. & Stevens, N. Colonisation by saltmarsh of former agricultural land following realignment of a sea wall at Pawlett Hams, Bridgwater Bay. Abstract...