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Severn Estuary RCZAS National Mapping Programme project

The National Mapping Programme (NMP) component of this Rapid Coastal Zone Assessment Survey (RCZAS) project was funded by English Heritage (now Historic England) and carried out by Gloucestershire County Council Archaeology Service. The aerial survey focused on the intertidal zone and up to one kilometre inland. The project was initiated primarily to provide an assessment of the Severn Estuary’s archaeological resource and to inform the future management of that resource in response to the threat from natural and human processes.

Colour aerial photograph showing a wrecked ship on tidal flats; the general shape of the ship is still visible
Remains of British “block ship”, the 1942 “Staghound” in Woodspring Bay, near Clevedon photographed on 19-FEB-2000 (NMR 18676/10) © Historic England

Ancient coastal fisheries

Some of the most significant archaeological features identified were the numerous fish weirs and traps located in the intertidal zone of Bridgwater and Blue Anchor Bays, dating from the 10th century period to the 20th century. At least four types of fish weir were identified by the survey, constructed of wood and stone. These variations may reflect the availability of raw materials, changes in construction design over time and the types of fish being targeted.

Colour aerial photograph showing a number of pale stone structures laid out on the intertidal sands
Medieval stone fish weirs in Minehead Bay, photographed on 19 March 1999. These are still maintained by local fishermen (NMR 18281/27). © Crown copyright. HE

Second World War coastal defences

Second World War military coastal crust defences were prominent features in the Severn Estuary intertidal zone, providing an interesting comparison with other military defences around Britain's coastline, such as those recorded by the Suffolk NMP. The survey highlighted the strategic importance of camouflage to disguise coastal military defences, especially pillboxes. The historical air photographs are valuable as few surviving examples retain their original camouflage. Numerous pillboxes were positioned along the coast between Porlock Weir and Blue Anchor, of which 28 were identified as a non-standard design known as an infantry section post.

Black and white oblique aerial photograph showing a strip of coast with a concrete structure on the edge of the beach
An infantry section post and pillbox near Dunster, photographed by the RAF on 27-JUN-1941. These had beach pebbles cemented to their exterior to help conceal them within the landscape (MSO31206-PO-056). Historic England RAF photography.

Historical images: an important pictorial record

Aerial photographs taken during the Second World War remain an important historical pictorial record of the nation's defences, as most of the sites recorded were removed soon after the war. These wartime images revealed anti-invasion defences of the Severn Estuary to be far more extensive than previously thought.

B&W vertical aerial photo showing two irregular banked structures, the top one of which contains a crescent shaped feature
An oil QF decoy site at Portbury photographed on 25-MAR-1946. It was constructed to look like bomb-damaged storage tanks at the Bristol and Avonmouth docks (RAF/106G/UK/1288 V 5240). Historic England RAF photography.

Trial lidar assessment

The survey included a trial lidar assessment of part of the flood plain of the River Parrett, Somerset and an area of possible Roman land reclamation at Elmore, Gloucestershire. Lidar was shown to be complementary to aerial photographs for the identification of archaeological sites and also for assessing their survival in both trial areas.

Severn Estuary Rapid Coastal Zone Assessment Survey: National Mapping Programme

Severn Estuary Rapid Coastal Zone Assessment Survey: National Mapping Programme

Published 1 December 2008

NMP report from the Severn Estuary Rapid Coastal Zone Assessment Survey (RCZAS) Project

The images used on this page are copyright Historic England unless specified otherwise. For further details of any photographs or other images and for copies of these, or the plans and reports related to the project, please contact the Historic England Archive.

For further information on a project or any other aspect of the work of the Remote Sensing Team please contact us via email using the link below.

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