Wave ramps at the back of the large Cronulla rock pool will be removed in a bid to stop the huge flow of sand into the enclosure.
Sutherland Shire Council will spend $80,000 on this work and improvements to the entry stairs, with the project scheduled for winter.
However, no work will be done on the smaller rock pool, which has a leak and does not maintain water depth.
The problems regularly prevent, or restrict, use of the two facilities and support the argument by some users a new rock pool should be built in the southern corner of Cronulla Beach.
Concrete ramps were built at the back of the large pool to assist waves breaking over it and thereby flushing it and maintaining water quality.
A council spokesman said, during this process, the pool frequently filled with sand and sometimes large amounts of seaweed, reducing water depth.
“The in-filling of the pool necessitates regular pool closure and mechanical removal of sand to re-establish the proper water depths,” he said.
“With changing seasonal tides and ocean conditions, the filling of the pool can happen over a number of weeks or several months and requires regular maintenance.
“With each removal approximately 2000-2500 cubic metres of sand is removed.”
The spokesman said, of all the potential causes of sand entering the pool, wave ramps at the back of the structure were the greatest contributor.
“The ramps cause wave run-up and overtopping of the seaward wall, enhancing the entry of sand and kelp carried by waves into the pool,” he said.
”Removal of the ramps should mitigate the ingress of sand into the pool.
“An investigation has concluded that the ramps can be safely and economically removed without affecting the structural integrity of the pool.
“It is proposed this work is undertaken in the coming winter in association with improvements to the pool entry stairs.
“Requirements of community groups that use the facility will be considered to ensure their programs can be facilitated during the work.”
The spokesman said $80,000 had been set aside for the project, which included improving the entry stairs.
He said the small pool had a leak, preventing water depth being maintained.
“However the shallow depth at low tide is preferred by many users, particularly those with young children,” he said.
The spokesman said the council believed it was more beneficial to use available funds on the main pool to increase the length of time it was available.