Elfrather See is a lake in North Rhine-Westphalia, Germany. At an elevation of 30 m, its surface area is 0.5 square kilometres (0.19 sq mi). The Elfrather lake, popularly known as E for short-sea, is located in the north east of the city of Krefeld on the border of the Elfrath district. The lake was created from a disused gravel pit, which has been filled with groundwater. The degradation was made in the Lower Rhine because of the low water level with typical wetness reduction construction of a dredger. The gravel was taken up in the 1970s for the construction of the A57 Highway, which was set up for the gravel pit as a place of central material supply.