The Mülheimer Ruhraue nature reserve includes the Ruhr meadows in the area of Mülheim city center and the river course. In the southern area of the area there are wet wasteland with high-rise meadows as well as willow bushes and a pond. Here the Mühlenbach flows into the Ruhr. In the southeastern area, the course of the Ruhr is separated from a canal ('lock canal') by a weir. While the Ruhr describes a loop to the west, the canal flows directly to the north. On the resulting island there is a wooded area on the meadow site adjacent to the weir. The two runs meet again in the north of the area. There is a gravel area here, which is largely made up of young trees. The FFH area DE 4507-301 lies to the south of the area. The entire biotope complex consisting of the Ruhr meadows and the river course determines the value. Here is a valuable retreat for many animal and plant species in the floodplains in the middle of the densely populated area. The area also has an important function as a recreation area. The combination of woody areas, wetlands and bodies of water is highly representative and therefore worth protecting in the sense of the protection goal concept for the natural environment. Impairments can be recognized, among other things, by strong neophyte spread and eutrophication. The area is a valuable part of the alluvial areas in the lower Ruhr Valley and is of outstanding importance for the biotope network.