The Hengsteysee (Lake Hengstey) is a

reservoir A reservoir (; ) is an enlarged lake behind a dam, usually built to water storage, store fresh water, often doubling for hydroelectric power generation. Reservoirs are created by controlling a watercourse that drains an existing body of wa ...

on the

Ruhr The Ruhr ( ; , also ''Ruhrpott'' ), also referred to as the Ruhr Area, sometimes Ruhr District, Ruhr Region, or Ruhr Valley, is a polycentric urban area in North Rhine-Westphalia, Germany. With a population density of 1,160/km2 and a populati ...

river between the cities of

Hagen Hagen () is a city in the States of Germany, state of North Rhine-Westphalia, in western Germany, on the southeastern edge of the Ruhr area, 15 km south of Dortmund, where the rivers Lenne and Volme meet the Ruhr (river), Ruhr. In 2023, the ...

Dortmund Dortmund (; ; ) is the third-largest city in North Rhine-Westphalia, after Cologne and Düsseldorf, and the List of cities in Germany by population, ninth-largest city in Germany. With a population of 614,495 inhabitants, it is the largest city ...

and

Herdecke Herdecke () is a town in the district of Ennepe-Ruhr-Kreis, North Rhine-Westphalia in Germany. It is located south of Dortmund in the Ruhr Area. Its location between the two Ruhr (river), Ruhr reservoirs Hengsteysee and Harkortsee has earned it t ...

North Rhine-Westphalia North Rhine-Westphalia or North-Rhine/Westphalia, commonly shortened to NRW, is a States of Germany, state () in Old states of Germany, Western Germany. With more than 18 million inhabitants, it is the List of German states by population, most ...

Germany Germany, officially the Federal Republic of Germany, is a country in Central Europe. It lies between the Baltic Sea and the North Sea to the north and the Alps to the south. Its sixteen States of Germany, constituent states have a total popu ...

. It was built in 1929 and is one of five reservoirs on the Ruhr. The reservoir is about long and has an average width of . It begins near the point where the

Lenne The Lenne () is a tributary of the river Ruhr in the Sauerland hills, western Germany Germany, officially the Federal Republic of Germany, is a country in Central Europe. It lies between the Baltic Sea and the North Sea to the north a ...

flows into the Ruhr, and ends with the

weir A weir or low-head dam is a barrier across the width of a river that alters the flow characteristics of water and usually results in a change in the height of the water level. Weirs are also used to control the flow of water for outlets of l ...

and hydroelectric plant of Hengsteysee. The Klusenberg, a hill that is part of the Ardey range, is located just north of the Hengsteysee. There is also a pumped-storage plant on this reservoir (called the Koepchenwerk after Arthur Koepchen), along with a 4.5 MWh grid services battery repurposed from electric cars. Hengsteysee fulfills the following four functions: *functions as the lower reservoir of the Koepchenwerk pumped-storage plant *performs biological purification of water from the Lenne *deposit of sediment from the Lenne *venue for

water sport Water sports or aquatic sports are sport, sports activities conducted on waterbodies and can be categorized according to the degree of immersion by the participants. On the water * Boat racing, the use of powerboats to participate in races * ...

s and tourism

Water sports

The Hengsteysee is a water sports area, especially for

sailing Sailing employs the wind—acting on sails, wingsails or kites—to propel a craft on the surface of the ''water'' (sailing ship, sailboat, raft, Windsurfing, windsurfer, or Kitesurfing, kitesurfer), on ''ice'' (iceboat) or on ''land'' (Land sa ...

rowing Rowing is the act of propelling a human-powered watercraft using the sweeping motions of oars to displace water and generate reactional propulsion. Rowing is functionally similar to paddling, but rowing requires oars to be mechanically a ...

and

canoe A canoe is a lightweight, narrow watercraft, water vessel, typically pointed at both ends and open on top, propelled by one or more seated or kneeling paddlers facing the direction of travel and using paddles. In British English, the term ' ...

ing. Several

sports clubs A sports club or sporting club, sometimes an athletics club or sports society or sports association, is a group of people formed for the purpose of playing sports. Sports clubs range from organisations whose members play together, unpaid, and ...

are based on the lake shore: the Hengsteysee Sailing Club (SGHS), Dortmund University Sailing Club (USC), the sailing group of the Hagen Disabled Sports Association (BSG) with its boathouse on ''Seestraße'', the Syburg Sailing Club, the Hagen Canoe Club and the Dortmund Sports Club (''Freier Sportverein Dortmund 1898'', FS 98). The DLRG groups of the county of Dortmund (there is a water rescue station on ''Hengsteystrasse'') and OG Hagen (water rescue station on ''Seestrasse'') ensure safety on the water. However, the Hengsteysee is unsuitable for swimming and bathing - it is not a

bathing lake A bathing lake is a natural or artificial lake that is used for public bathing and swimming. In the water, bathers mostly remain close to the shore and use the area for recreational purposes, such as sport, games and sunbathing. In Europe, becaus ...

, and the

water quality Water quality refers to the chemical, physical, and biological characteristics of water based on the standards of its usage. It is most frequently used by reference to a set of standards against which compliance, generally achieved through tr ...

of the Ruhr is not good enough for a suitable permit. The health department has also expressly warned against this since September 2008, when several people had to seek medical treatment after coming into contact with the lake water. Hengsteysee 2008 Wasserpest 3

Due to the low water depth (less than 50 cm in some places) at times and especially due to the mass proliferation of the waterweed ''Elodea'' in summer since the late 1990s, water sports on the Hengsteysee have been severely curtailed.

References

Reservoirs in North Rhine-Westphalia RHengsteysee {{NorthRhineWestphalia-geo-stub