Brown trout can be found in suitable cold water habitats, including lakes, reservoirs, streams and rivers. Grand Lake, Brown trout at 10 inches to 15 inches are becoming piscivorous, feeding primarily on fish and crayfish, along with detritus and algae. Nutrients that are needed for our Brown trout populations. The typical growth rates of brown trout are considered to be around 10cm (4 inches) per year for the first three years after which growth slows to roughly 5cm (2 inches) per year. The removal of nutrients in the lake will affect the growth rates of our Brown trout population.