Ashburton District Council is continuing to work with hutholders at Lake Clearwater to decommission long drop toilets.
Long drops are believed to be contributing to contamination in the lake and all must be physically decommissioned.
Speaking to councillors last week council strategy and compliance group manager Jane Donaldson said 70 long drops had initially been identified at Lake Clearwater.
That number was now down to 29, of which 20 properties had long drops only and nine had a long drop and holding tank.
Ms Donaldson said council was in talks with some of the hutholders about their intended action, but there had been no contact with 23 of them.
She said those hutholders would shortly receive a letter from council telling them it was their last chance to co-operate before enforcement action commenced.
Council has also demolished a long drop toilet near the waterski club at Lake Camp and has some funding earmarked to rebuild a new block.
The new block will have a facility to empty camp toilets.
Council is currently asking for feedback from stakeholders and the public on a 30-year plan being developed for lakes Camp and Clearwater.