 Although the landscape features of the site are mainly derived from gravel pits and settling pools alongside the River Avon , the area was originally farmland , and the first pools were created by mining subsidence in the 1940s and 1950s caused by workings at <unk> Colliery . The site was of interest to local naturalists for its range of bird life , especially as by 1959 the area of open water was far larger than it is now , although much was lost when Severn Trent Water dredged it in 1963 . Shortly afterwards the first official attempts at using the site for conservation purposes came when the West Midlands Trust for Nature Conservation , supported by the West Midland Bird Club began moves to secure the site as a Site of Special Scientific Interest ( SSSI ) . The Brandon Marsh Conservation Group was formed in 1968 , and by 1973 the site had been confirmed as an SSSI . In 1981 , the Warwickshire Wildlife Trust ( the successor to the West Midlands Trust ) came to an agreement with Lafarge whereby the site is leased for a period of 99 years at a peppercorn amount of £ 1 a year , leading to the creation of the nature reserve . 
