Gilbert Heathcote's tunnel was an engineering project dating from the 1630s as one of the earliest modern attempts to drain The Fens in Lincolnshire. Rendered obsolete by the mechanical drainage improvements after World War II, it was finally removed in 1991. In 1871 the Bourne South Fen Drainage District was formed to take over the drainage, which had been in the hands of adventurers, and from 1872 a succession of steam engines were used to assist the flow through the tunnel. The area drained falls within the area of the Welland and Deepings Internal Drainage Board.