Harpen ponds

Milky cloudiness from the pit water of the Robert Müser colliery

Inflow of the pit water

The Harpener Teiche , also known as Werner Teiche , are two still waters on the border between the Bochum districts of Harpen and Werne near the Ruhr-Park shopping center . Originally laid out as mining clarification ponds, they are now a recreational area.

The Harpener Bach feeds the two bodies of water. In addition, warm mineral-rich pit water from the former Robert Müser colliery is discharged into it, which leads to a milky, cloudy color and sometimes to unpleasant smells. The high chloride content (up to 40 grams per liter) and the constant 20 ° C temperature of the pit water favor a special fauna and flora at the discharge point. According to the European Water Framework Directive, water bodies must be returned to their natural state by 2015; However, the RAG has an exemption from the Arnsberg district and may continue to initiate it until 2021.

The northern pond is 230 meters wide and 180 meters long, the southern maximum 140 meters wide and 460 meters long. A hiking trail leads between the two ponds to the former dump of the Robert Müser colliery.

Mallards, pond and white claws, grebes and swans breed at the pond. Gray herons as well as house martins and barn swallows can also be observed. The city of Bochum has set up benches along the way and created the wedding forest.

In 2009, the Bochum Botanical Association examined the biodiversity of the Harpen ponds and detected the red kite , skylark and ant cricket in rare and remarkable animals , as well as the sand sedge , the tufted carnation and the frog rush in plants.