"It's very high. It's raised the sand by about 20cm making it extremely high at the moment."
With summer having officially began on Saturday, the high water level was disappointing, Mrs den Hertog said.
"I felt a bit sad to see it that high with summer coming. The locals and those holidaying here won't have a beach to sit on or anywhere to play. There is no beach and the picnic table is under water."
As for camping there - no chance, she said.
"I told my husband there won't be any camping because it's illegal and they will get wet."
One Lake Rotoma holiday park owner, who didn't wish to be named, said the high water levels had been a problem for a few years, which was of concern.
"The problem is there is no outlet, it's an uncontrolled lake. Technically, it could fill up and flood." High lake water levels at Tikitapu (Blue Lake) have also been high, since a storm in early 2010.
Blue Lake Top 10 Holiday Park worker Matt Clarke said there was no longer a beach at the lake across from the motor camp.
"Every time it rains now, it floods what little is left of the beach. It leaves such a small space people can use."
While walkers can still walk around the entire lake, it's a shame people can't enjoy the beach anymore, Mr Clarke said.
"On a nice day it used to be packed. It's sad there is no longer a beach."
Lakes Rotoma, Rotoehu, Okataina and Rerewhakaaitu are slightly more than 1m higher than normal, with Lake Rotomohana 2m higher than usual. Rotorua harbour master Pererika Makiha said the jetty and ramp at one of the Lake Rotoma motor camps had been closed for safety reasons and signs erected at other ramps warning people they were slippery.
"From a navigational perspective, higher lake levels can submerge some public ramps and jetties. This can be a hazard to people when launching or retrieving their vessels."
Regional Council general manager natural resources Warwick Murray said the water levels were very high at the moment because of heavy rainfall throughout the winter months. Other factors include groundwater inputs, lake sizes, stream flows and evaporation. While the levels normally rose during the winter, they weren't usually this high at this time of the year, he said.
"Ground water levels are much higher at the moment but we can expect to see it easing off with less rainfall in summer."
Lakes Rotorua, Rotoiti and Okareka are controlled.
"In most cases the lakes have natural outlets with no means of controlling the water levels ... it is difficult to predict how lake water levels might change."
The regional council regularly monitors the lakes.
