Lower Horse of islands (five of which later re-clustered to form Canvey Island), that broke away from the English coastline in the medieval period. Lower Horse Lower Horse is a uninhabited island off the English coast, lying in the Thames Estuary between Canvey Island and Stanford-le-Hope, close to . Administratively it is part of Thurrock unitary authority; the border with its ceremonial county namely the administrative county of Essex runs between it and Canvey Island. Smaller than normal markings for an area of saltings (traditional, open air, sea salt extraction through drying) appear in the Ordnance Survey map of 1919, which confirms
River Sheppey where it joins Whites River and then the River Brue near Westhay. The water quality is generally good; however, there have been some discharges from sewage treatment works in the area that can contribute to nutrient levels in rivers. Signs of nutrient enrichment are noticeable at times of low flow and the ecology of the Sheppey is adversely affected in its upper reaches. It would appear that the Sheppey was only so called in the late 19th century. Prior to then, if it was called anything, it was probably Doulting Water or the River Brae. The Sheppey has been used