 Discharge to the Trent was subsequently moved to Keadby, and the gravity drainage was supplemented by pumps when a pumping station was built in 1940.Steam engines were gradually replaced by diesel engines, and later by electric pumps.The Environment Agency maintain eight pumping stations on the Chase, in addition to Keadby, and there are a number of smaller installations managed by the Corporation of the Level of Hatfield Chase Internal Drainage Board.