Soft river banks, soft materials in hard river banks or indentations in hard river banks. These are also known as natural embankments.
Natural embankments provide a gradual transition from land to water and take nature and the landscape into account. Natural embankments are not steep like traditional river banks: they have different levels that are submerged in shallow water permanently or periodically. The shallow slope breaks waves and the vegetation that takes a hold here enhances that effect. The embankments are natural repositories for rainwater and they are exceptionally important for amphibians and dragonfly species. They are also breeding grounds for many types of bird. The low flow velocity which is typical of these areas means that many species of fish can spread along the river. In addition, natural embankments help to clean up the water and they supply other public and natural services.
Many waters in the urban area have hard banks. This means they fail to comply with Dutch and European nature objectives, which actually require the opposite: a nature-friendly bank with a natural slope. In many cases, nature can take over from hard banks and, in that way, supply numerous public and natural services.