The repeated vandalism has also included a donation box being ripped off a wall, a fire lit on the steps next to the hot pools, and rubbish being left behind including disposable nappies.
This vandalism costs the department in not only repair expenses, but also staff time.
Ms Norgate said this was essentially theft from the Crown and from the general public.
"People who damage these sites, light fires in fire ban areas or leave rubbish are committing an offence and they can expect to be prosecuted."
Information from the public and the department's security cameras had been very helpful in identifying those who were mistreating the land, she said.
Members of the public who witness any similar events are asked to call the department on 0800 DOC HOT.