The Queenstown-Lakes District Council says new restrictions on freedom camping have had a dramatic effect.
The Freedom Camping Act became law in August last year and allows councils to issue instant fines of $200 to campers polluting open spaces they visit.
The act also allows councils and the Department of Conservation to ban camping in certain places.
The council says complaints about picnic spots being marred by rubbish and human waste used to be among residents' regular top five grievances.
But since the new law took effect, it says the number of incidents of pollution by tourists has nosedived. About 150 instant fines have been issued.
Community services general manager Paul Wilson says local camping grounds have also benefitted from a rise in patronage.