SK53
Yes, there may be other things (bare rock, pools, swampy areas) which may fall within the riverbed. There are relatively few rivers in CH like the Landquart where the river has not been disturbed, and so still qualifies as a wild river. Given that the water levels in the Davosersee are tightly regulated (I met the American with the contract to manage the levels once on the train towards Klosters Dorf), even the Landquart is not immune. However, as it is very accessible it would be a good one to have mapped in detail (the Ruinaulta would be another one).