The Sennesee is a lake created by sand mining south-east of the town of Schloß Holte-Stukenbrock.
The Sennesee is located in the Senne in the east of the Gütersloh district. The roughly 13.5 hectare body of water lies entirely within the area of the town of Schloß Holte-Stukenbrock. Together with an approximately 4.4 ha large body of water to the west and separated from the main lake only by a road, the Sennesee represents the largest body of water in the city area.
The course of the Furlbach is just south of the lake area, but there is no direct connection to this body of water or only via the groundwater.
The Sennesee has been included in the biotope register of the State Institute for Ecology, Land Use and Forestry NRW and is therefore to be regarded as a biotope worthy of protection under the North Rhine-Westphalian State Nature Conservation Act. For this reason, there is a ban on bathing in the body of water and a ban on using it for water sports. The Sennesee, on the other hand, is approved for fishing.
Source: Wikipedia