The mirrows reach or grayling zone

This zone has a less steep gradient, than the trout beck. The river here still flows swiftly, though the current is not fast and conditions are not torrential. Erosion is thus comparatively less. Some silt may be deposited in the quieter-flowing areas. In areas with moderate currents filamentous algae may grow in summers. Other plants can gain a foothold where silt is deposited with further silt accumulating among their roots.

The presence of these quiet areas with water plants is characteristic of this stretch. The water is still well oxygenated though its temperature is more variable. Areas of fast flowing water or riffles now alternate more regularly with long pools. Fish characteristic of this zone are mirrow and in some regions grayling. The fish of the trout beck zone are also found here and so is the eel and in some rivers young offspring of salmon.