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| Sefton Coast Partnership | Shoreline Management | Nature and Wildlife | Coastal Heritage | Visiting the Coast | Students and Teachers | Coastlines | |
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Winter 1999Coast erosion at HightownArticle by Tony SmithA history of the training of the Alt The coast between Blundellsands and Altcar has always been influenced by the River Alt, which emerges onto the shore at Altcar and is then deflected to the south by the prevailing drift of sand from Formby. The river intercepts this sand and carries it seaward. The river's course along the shoreline has always been variable. At the beginning of the 20th century it moved south and began to erode the Crosby shoreline. Residential seafront properties were abandoned as the coastline slowly eroded, despite attempts at artificial hardening. After an unsuccessful attempt to blast a new channel in 1929 the river was finally brought under control by the construction in 1936 of a stone training bank that directed it seaward a kilometre north of Hall Road. From 1936 to the mid 1970s the formerly eroded coastline was artificially reinstated by the tipping of demolition waste, builders' rubble and slag from local smelting factories. In the 1970s coast protection works were undertaken to protect the developed land between Seaforth and Hall Road West. The coastline north of Hall Road West has continued to erode, particularly at the landward meanders of the rivers course. In about 1980 the members of the Blundellsands Sailing Club placed large concrete blocks on the shore, forming a hardened promontory around the seaward flank of their premises. Present Conditions The Alt training bank has deteriorated and settled over the years. It was repaired and reinforced in 1949 and 1969 but is now not much higher than the adjoining shore. Any breach in the bank would allow the river to return to the Crosby shoreline. This would then lead to the progressive failure of the Crosby sea wall. Hightown is built on sand dunes, with typical ground levels at least 2 metres above the highest tides. In its immediate agricultural hinterland, however, ground levels are lower than the highest tides. Here, pumping is used to drain the land into the River Alt, which itself is pump-assisted to the sea. Just north of the Alt training bank, there is a narrow strip of tipped land that is slowly eroding. The shore has continued to erode at the Sailing Club, undermining and threatening to topple their defences. Unless further intervention is undertaken the clubhouse may soon have to be moved inland or abandoned. Material eroded from the hardened coastline near the training bank is slowly spreading northward across the Hightown shore. It has formed an artificial beach that helps to slow down the process of coast erosion but it has hazardous projections and contains contaminants derived from its former uses. Immediate recommendations The Shoreline Management Plan for this area recommends that the Council should commission a strategic study with the objective of discovering the most suitable and sustainable form of coastal defence. It includes recommendations for monitoring the underlying physical processes and the corresponding behaviour of the shoreline. There is a need to put in place a system of measurement that can also be monitored by local residents so as to establish a more scientific basis for intervention. The next stage in the preparation of proposals for coast defences along the Crosby-Hightown shore is to prepare a Strategic Assessment of the project in relation to a wider coastal area. The initial scoping study will look at the coastline from Crosby to Formby Point to determine the coastal processes and other factors in this zone. For information please contact;
Graham Lymbery
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