Construction of the multimillion-dollar Kingswim aquatic facility in Calwell is about a third of the way through and expected to be completed before a late September opening.

Development of the pool has been plagued with uncertainty, largely due to extension of time fees.

Developer Phil King originally considered pulling the plug on the proposed $3.3million centre last October after the government only waived a portion of $300,000 in late fees.

Earlier this year Mr King’s situation was reassessed as part of broader changes to the fees, designed to discourage land-banking in the ACT. A significant portion of the money was waived, allowing the project to continue.

Mr King said construction works were on track and enrolments would open soon.

Once completed the 20-metre pool will primarily focus on teaching children how to swim.

Other services will include aquatic exercise for adults, hydrotherapy, discounted school programs, school holiday programs and access to swimming club competition.

"The facility will be programmed for up to 4000 users a week [who] will come at dedicated times," Mr King said.

"If people are doing lap swimming they will have a cleared time for lap swimming. If people want to do hydrotherapy they will have the pool to themselves."

Mr King said the pool had been specifically designed to cater for the various programs, ages and swimming abilities using the water.

"The water temperature is going to be 32 degrees during summer and 34 degrees during winter, which is ideal for hydrotherapy and physiotherapy and aquacise and ... for parent and child classes," he said.

“But it’s not hot enough that the squad kids can’t do some reasonable training.”

The centre will employ about 70 staff, with most of those to be casual.