Some Problems of Subsidence and Land Use in the Mid-Cheshire Industrial Area

Abstract

Industrial devastation is a major problem of all mining areas which undoubtedly warrants the incre sing attention being paid to it by geographers.1 A geographical approach to the study of derelict land, subsidence, and the disposal of industrial waste is valuable in providing data on the evolution of industrial landscapes and, more important, forms a basis for planned reclamation and restoration. In a paper previously published in the Journal% the unique subsidence phenomena of the mid-Cheshire saltfield were dicussed mainly from the standpoint of morphology and historical evolution. This short paper forms a sequel in which it is intended to amplify some of the points then raised, but not fully explored, relating to the effects of subsidence on human activities; in particular it draws attention to some new features of the land use problems of the saltfield which it was not permissible to publish when the original paper was prepared in 1954. Subsidence in its more violent forms is now rarely experienced in mid-Cheshire; the cataclysmic upheavals of the late nineteenth and early twentieth centuries have given way to a more insidious form of subsidence which works stealthily to the same end?dereliction. The change is to be explained largely by the adoption of different techniques of salt working, and by shifts in the location of salt manufacture. An important result of this latter change has been the appearance of subsidence in new areas within the saltfield, mainly near Sandbach. Subsidence was first experienced in this area during the eighteen-nineties, and was probably caused by the pumping of brine at the Wheelock salt and chemical works; it was then relatively insignificant in comparison with the great havoc wrought at Winsford and Northwich, the dominant centres of salt and chemical manufacture. However, after the First World War there were significant changes in the organization and distribution of the mid-Cheshire salt industry, which resulted in the virtual disappearance of salt manufacture from Northwich, the stagnation of the industry at Winsford, and its rapid expansion at Middlewich and Sandbach. 3 The consequent changes in the distribution and character of industrial dereliction can be seen from a comparison of the two maps (Fig. 1: a, b), which show the several elements of the industrial landscape in 1932 and 1957 respectively. The growth of the salt industry at Middlewich and Sandbach was accompanied by the formation of several large subsidence flashes within the area (Fig. 2a). Most of these were of the trough-like variety associated with natural brine pumping and, as they often lay in the valleys of rivers and small streams, the troughs were soon permanently flooded. It is unfortunate that the growth of salt manufacture in this part of the saltfield antedated the introduction of controlled brine pumping for, although most of the damage has occurred in unpopulated areas, this southward expansion of subsidence is a disturbing feature which shows little sign of abatement.4 Just as the expansion of salt manufacture at Middlewich and Sandbach has had unfortunate repercussions, so the almost complete decay of the salt industry at Winsford has appreciably reduced the incidence of subsidence. The great flashes to the south of the town have grown but little since the nineteen-thirties (Fig. 1: a, b) and have begun to silt up in part. In the Northwich area the introduction of controlled brine pumping by the chemical industry, the abandonment of the brine shafts which tapped the bastard reserves in the flooded rock-salt mines, and the contraction of the salt industry have combined to make subsidence much less virile than it formerly was. This does not mean to say that subsidence is no longer a problem over much of