Sherburn said the streams were noted for good runs of brown trout into December "and our monitoring trap on the Ngongotaha Stream has shown there are lots of browns from 2.5kg to 3kg, and some even bigger".
"There are a few fresh run rainbows in good condition too."
Sherburn said brown trout from the Ngongotaha Stream were regarded as some of New Zealand's best.
Most experienced anglers will be nymphing or using globugs but big traditional wet flies fished downstream on sinking lines work well too.
Sherburn said anglers who took advantage of the change of light and fish the streams in the early morning or late evening usually do the best.
While some areas are fly fishing only, spin fishing is permitted on some streams.
Sherburn said anglers are advised to check their regulation booklets for where they could spin fish, or phone Fish & Game on 07-357 5501 to ask.
Fish & Game officers will be out ranging at the opening of the streams, and in the weeks that follow, talking to as many anglers as possible, and checking their compliance with licence and other regulations.
"Please remember to have your fishing licence with you," Sherburn said.
At Waikaremoana, the Mokau and Hopuruahine Streams also open on Saturday, providing anglers with exciting prospects for the summer.
"Many of the fish will have left the Waikaremoana streams by December after spawning over winter, but it's likely there will still be a few present for keen anglers to pursue."