The 9-month-old birds were raised at the captive breeding centre near Twizel as part of the Department of Conservation's black stilt recovery programme.
Young home-schooled children from Omarama released the birds near the Lake Pukaki delta.
Earlier in the week, 46 birds were released by pupils of Lake Tekapo School and Haldon School near Lake Tekapo.
The releases are carried out for the recovery programme each year and will help boost the wild population.
"We have certainly come a long way from the early 1980s when there were only 23 adult kaki left in New Zealand.
If these recently released birds can survive to three years of age, then they are able to breed and further increase population numbers," Doc biodiversity manager Dean Nelson said.
Better conditions at the captive breeding centre have improved chick survival and increased the capacity.
Two wooden aviaries, built in the late 1980s, will need replacing soon.
The fifth year of a large-scale Tasman Valley predator control project has also been completed and the outcome looked promising for black stilts, as well as other bird, lizard and invertebrate species.
However, it was an ongoing challenge to keep the population increasing as the resources required were "quite significant", Mr Nelson said.
