All height restrictions are being removed from the hydroslides at the Hanmer Springs pools in Canterbury.
Riders must still be at least five years old, but will no longer need to stand beside a board to check if they are tall enough to hit the 1.2 metre limit.
Hanmer Springs Thermal Pools and Spa marketing manager Shane Adcock said it was fantastic news for visitors.
He said the design of the new Violet Vortex and Waiau Winder slides that opened in October, replacing two 25-year-old rides, allowed the pool to make the call.
"Those two new slides have what we call runout shoots- so they have a shallower pool of water that you finish the ride in, much like our Conical Thrill and SuperBowl rides. Those runout shoots effectively replaced a splashdown pool, which was a deeper pool," he said.
"The health and safety risk of landing in a pool at the bottom of a slide is no longer there, and so we felt that we could remove the height restriction that had previously been in place."
Adcock said the slides had been thoroughly tested in terms of managing risks, and the decision also came after recommendations from slide manufacturers.
Age and weight restrictions will remain in place for the four slides.
Adcock said there had been good numbers through the pool this summer, and people had been enjoying the new hydroslides.
"We've had some really good feedback on the new slides, particularly the use of LED lighting through those slides. It's quite a different experience that is certainly not in many areas around New Zealand, if at all."