I simply could not write a poem about a river, a song yes, but honestly how would one put cadence on water using words, it's impossible. Poetry is for ponds or pools.
Liquid movement needs to be represented by activity; an attempted onomatopoeia from the glossary of musical terminology and not a mere element of vocal expression.
Our meandering aqua-ducts are conducted by nature, part of a symphony, an orchestra accompanies them every step from their trickling springs to les grandes fleuves à la mer.
I couldn't write a poem about a river, rhapsodies over rapids, frothy fermatas, prestos, tempos, streaming ouvertures, dammed ritardandos, torrential tremolos, catchment syncopations, sand bars.
What about swishing droplets from the metal cymbals of mill wheels or hanging branches flapping in rhyming meter or clapping swan's encore echoes under arched bridges? Yes, Tennyson wrote one; But that was just a Brook.