Brown trout live in many rivers in the Stour Catchment. They prefer clear water and gravelly or stony river beds (as found in chalk streams) as these are the areas they use to spawn, from January to March. They are predatory, feeding on small fish and insects and can be seen jumping to catch flying insects such as mayflies. KSCP carry out river conservation work that will benefit brown trout and other fish, including the removal of man-made structures that can impede movement. Any enhancement to habitat that increases fish numbers will also benefit many other aquatic species. Brown trout are a Priority Species in the UK Biodiversity Framework.

The migratory sea trout can also be found in rivers in the Stour Catchment. Sea trout have now been recognised as being the same species as brown trout, but they live most of their life in the sea and only return to rivers to spawn.