They didn't build a road in the middle of the river. The river flooded and the water went over the banks and into streams. Then it went over the banks of the streams into ditches. Then it filled ditches and spilled over the road. Spawning salmon can't be legally caught and consumed unless you are a bear 😆 and they are just doing what they do, which is swim. This water over the roadway is due to excessive rainfall, which happens in the Pacific Northwest of Washington state. All. The. Time.