In Gbaya, the notion of (almost) dried up water of the rivers is emphasized in Isaiah 42:25 with ɗuŋgum, an ideophone that describes the movement or motion of shaking.

Ideophones are a class of sound symbolic words expressing human sensation that are used as literary devices in many African languages. (Source: Philip Noss)

Note that the ideophone ta̧i̧-ta̧i̧ in the same verse, discussed in body of water dried up refers to the completely dried pools.