Hello Irma IRM-ED. It appears that this river is a section under a dam. Guidance on how to map around this feature type is found here - waterway=dam.
where they cross it (flow through it). It states, "If the river runs in a tunnel well underneath the dam it should be mapped as waterway=river + tunnel=yes + layer=-1.” Just make sure to split the river feature on either side when adding that tunnel section. Happy mapping!