Hennetalsperre

Hennetalsperre
Name	Hennetalsperre
Location	North Rhine-Westphalia, Germany
Dam type	Gravity/earthfill
Status	Operational
Opening	1928
Owner	Regional water authority
Reservoir name	Hennesee
Capacity total	20e6 m3
Catchment	180 km2
Surface	1.3 km2
Max length	4.8 km
Max depth	30 m

Hennetalsperre is a dam and reservoir complex in North Rhine-Westphalia, Germany, known regionally as the Hennesee. The facility functions for flood control, water supply, and recreation, situated within the Sauerland uplands near Meschede and Arnsberg. Its presence influences local infrastructure, transport corridors and regional planning frameworks across NRW.

Overview

The Hennetalsperre forms part of a network of German waterworks that includes the Rurtalsperre, Möhnetalsperre, and Edersee, and interacts hydrologically with tributaries such as the Ruhr and Lenne. Located near the municipalities of Meschede, Arnsberg, and Bestwig, the site lies within commuting distance of Dortmund, Bochum, and Essen and within the tourism orbit of the Sauerland-Rothaarsteig region. The reservoir supports municipal suppliers like Stadtwerke Meschede and regional authorities such as Bezirksregierung Arnsberg, while adjacent conservation areas connect to initiatives by the Naturschutzbund Deutschland and Landesbetrieb Wald und Holz NRW.

History and construction

Planning began in the 1920s amid interwar infrastructure programs that also produced projects like the Bautzen Dam and Rappbode Dam. Construction involved engineers trained in institutions such as Technische Universität Berlin and RWTH Aachen and employed techniques similar to those used at the Möhnetalsperre and Edersee. During World War II the site faced strategic considerations comparable to those affecting the Ruhr dams and later Cold War civil defense planning. Postwar rehabilitation drew expertise from Bundesanstalt für Gewässerkunde and reconstruction efforts coordinated with regional bodies including Regierungsbezirk Arnsberg and Kreisverwaltung Hochsauerlandkreis.

Specifications and engineering

The structure combines gravity masonry and earthfill components, drawing on design principles used at the Schluchsee and Wanstead projects and analyzed in publications from the Deutsches Geotechnik-Kolloquium. The dam crest accommodates road access linking to Bundesstraße routes and rail corridors serving Deutsche Bahn stations in Meschede and Fröndenberg. Hydromechanical installations include spillways and valves manufactured to standards promoted by DIN and overseen by TÜV engineers. Instrumentation for seepage, piezometers and inclinometers references methodologies from the Technische Universität Dresden and the Universität Stuttgart water resources curricula.

Hydrology and reservoir management

The catchment integrates headwaters feeding the Henne and connects to watershed management schemes coordinated by the Ruhrverband and Landesamt für Natur, Umwelt und Verbraucherschutz Nordrhein-Westfalen. Operational objectives mirror those of the Rurtalsperre and Bigge reservoir regarding flood attenuation, low-flow augmentation for downstream abstraction points like Möhnewerke, and hydropeaking mitigation for ecological flows. Monitoring networks employ telemetry protocols adopted by the European Flood Awareness System and hydrometric stations that report to the Deutscher Wetterdienst and the Global Runoff Data Centre.

Ecology and environmental impact

Ecological considerations align with Natura 2000 designations and species protection under Bundesamt für Naturschutz guidance, affecting habitats for bird species observed by NABU and flora catalogued by Botanischer Garten und Botanisches Museum Berlin. Management measures have addressed eutrophication similar to interventions at the Steinhuder Meer and Baldeneysee, working with research groups from Universität Münster and Helmholtz-Zentrum für Umweltforschung. Riparian zones interface with forestry practices administered by Forstamt Arnsberg and habitat corridors connected to the Rothaargebirge conservation landscape.

Recreation and tourism

The reservoir supports recreation analogous to activities at the Biggesee and Sorpesee, including boating regulated under Wasser- und Schiffahrtsamt rules, angling coordinated with local Anglervereine, hiking linked to the Sauerland-Höhenflug and Rothaarsteig long-distance paths, and cycling routes managed by Tourismus NRW. Nearby municipalities promote cultural attractions such as the Hohensyburg historic site, the Möhnesee festivals, and local museums like the Hennesee Erlebniszentrum, attracting visitors from Dortmund, Cologne, and the Ruhr metropolitan region.

Administration and ownership

Ownership and administration involve regional entities similar to those managing other NRW reservoirs, with responsibilities shared among the Ruhrverband, Kreisverwaltung Hochsauerlandkreis, and municipal utilities such as Stadtwerke Meschede. Regulatory oversight intersects with Landesbetrieb Straßenbau NRW for access infrastructure, Wasserrechtsamt for water permits, and Landesamt für Natur, Umwelt und Verbraucherschutz Nordrhein-Westfalen for environmental compliance. Technical audit and certification processes reference standards from DIN, DVGW, and TÜV Süd.

Category:Dams in North Rhine-Westphalia Category:Reservoirs in Germany Category:Sauerland