She said she used to close the toilets before the "Supercity" Auckland Council was formed and handed the contract to a security company.
"Throughout the summer, we wouldn't even try to lock up until 9.30pm or 10pm because we understood people were still on the beach."
Now the job can only be done by a registered security contractor.
However, the guards were on a tight timeframe and weren't going to hang around longer to keep the toilets open.
"There is a big problem with freedom campers out here just parking up anywhere," she said.
"And when the toilets are locked at 8.30pm and not unlocked until 6.30am - even though they have got those self containment stickers - they don't want to use the toilets in them.
"Because nobody wants to empty a chemical toilet, it is just nasty."
Auckland Council head of operational management and maintenance Agnes McCormack said her team was "concerned to learn of this unpleasant situation" through media reports on Thursday.
"We'll have portaloos out at Piha by Friday morning and will be arranging for a cleaning crew to head out there and clean existing facilities," she said.
"We will need to review the number of facilities available in the area to ensure these unsatisfactory situations don't continue.
"As mentioned before, we had not been alerted to the problem and we would ask that if residents do have concerns, they contact us immediately to report the issue."
Anderson meanwhile said it was also good from a neighbourhood watch perspective to have a local lock up the toilets because they were more attentive to what was going on.
Anderson said a few years back a young man had died in his car close to one of the toilets and yet the security guards failed to notice.
"Having a local close up the toilets means there are locals driving that route twice a day and noticing if there is a car parked with nobody in it for a few days."
She said she wasn't afraid to go up to visitors and chat to them if they were drinking late or causing a disturbance.
"On New Year's Day, I paid for a guy to get a taxi back to town because he was absolutely drunk, his mates had left him behind," she said.
"I don't want that guy running around our neighbourhood at night, coming on to the camping ground, scaring my campers.
"That $100 was worth the price to get him out of our community."
Waitākere Ranges Local Board member Sandra Coney was happy to take up the issue with council to see if the toilets could be kept open later than 8.30pm.
"Not everybody is tucked up and in bed by 8.30pm, we can certainly look at whether they can be kept open longer," she said.
However, a delicate balance needed to be kept between providing services and encouraging freedom campers to camp illegally.
She said locals seemed to have gotten on top of the problem of freedom campers lately as she was getting much fewer complaints about them.
However, according to media outlet Stuff many residents were concerned their toilets were "just not good enough".
"The freedom campers get blamed for poops in the dunes but it could also quite easily be other visitors," Stuff quoted one woman saying.
"The toilet's are a stinky mess when there's a lot of people around."
She said it was stupid to close the toilets at 8.30pm when it didn't get dark till 10pm in summer.
"There's people still at the beach – what toilets do they use?"
