The River Ruhr is no designated bathing water complying with the specifications of the EU bathing water directive, even tough its water quality has continuously improved in the last few years thanks to the Ruhrverband's 72 sewage treatment plants. Especially in the case of heavy rains it cannot be ruled out that sewage flowes into the river untreated causing it to exceed certain limits. Swimming in the Ruhr is therefore generally forbidden.
But those looking for a good swim or splash can spend their leisure time at the designated swimming areas which the Ruhrverband has set up on the Bigge, Henne, Lister, Möhne and Sorpe Reservoirs. By the way: In 2009, all of the Ruhrverband's reservoirs were of excellent or good bathing water quality according to the European bathing water report. An overview of designated bathing areas in North Rhine-Westphalia complying with the EU bathing water directive can be found on an interactive map provided by the North Rhine-Westphalian Agency for Nature, Environment and Consumer Protection (LANUV).
Outside of the designated bathing areas, swimming is generally not allowed in the Ruhrverband's reservoirs. Barbecues and campfires are also strictly forbidden in the forests surrounding the reservoirs due to the risk of forests fires, in particular during the summer.