rapidless

adj

1. Without rapids.

   “"The river itself is flat and picks up quite a bit of current in highest flows, but otherwise it is a straightforward, rapidless section of beginner water."”

2. having no fast rivers or streams

   “The Zambezi contains at least 14 species that were not found in the Kwando River; ten of these species are strongly rheophilic, explaining their absence in the rapidless and rockless Kwando-Linyanti.”