Lake Hood, near Ashburton, fishes well early in the season, and it has an extra 50-odd trout relocated from the Ashburton-Lyndhurst irrigation scheme.
Central South Island Fish and Game officer Rhys Adams said the season opened on October 1 and the main waters of interest for anglers were the Rangitata and tributaries of Deep Stream and Deep Creek, the Ashburton River and its tributaries, and Lake Hood.
Early in the season, brown trout can congregate around the river mouths and lower reaches as they target food sources such as mullet, smelt and whitebait.
Anglers would do well to imitate that food with lures and flies.
The lower reaches of the Rangitata and the Ashburton were the areas to target.
Mr Adams said river flows were healthy.