In May, Milton residents raised concerns when leaders of the Bruce Community Facility project revealed cost estimates for a proposed new pool and library/service centre of more than three times those originally discussed.
A concept design publicised by project co-funder Clutha District Council following annual plan consultation in 2019 was priced at $5.8 million.
However, expanded plans for the complex presented for community consultation last month ranged from $13 million to $20 million.
Those revised figures were thrown into doubt once more during hearings at Milton Country Club on Thursday, as professional pool consultant Iain Ansell, of Christchurch construction firm Apollo Projects, spoke to his submission.
Mr Ansell said concept designs for the new complex were unlikely to come in under target budgets.
"I genuinely struggle to see how your project as currently shown will meet budget," he said.
"Six to eight lanes is too costly for the ratepayer base. Construction costs are exploding and the budget you are debating won’t be the reality.
"Pools are very costly and expensive to run; you need to maximise the users and ensure you cater for as wide a range of users as possible."
He proposed an alternative of a three- or four-lane lap pool combined with a secondary hydrotherapy/learning pool, to cater for the widest cross-section of users.
"Pools tend to get hijacked by architects who say you can do everything within one pool, but each activity has its own optimal temperature.
"Typically multi-use pools tend not to work well for any particular given thing."
Clutha Mayor Bryan Cadogan thanked Mr Ansell for his submission, saying he had given stakeholders "pause for thought".
Among others speaking to their submissions were Milton sisters Zoe and Liv Schiller.
Liv said she, her sister and her friends all wanted a new pool and library in which to spend their leisure time.
"It would be a lovely place to go if you’ve had a rough day, and want to relax in the warm. And because the new pool will be open all year round, we can get a ton more swimming in."
Her sentiments were echoed by a majority of the 122 submitters to the process.
About three-quarters of respondents favoured a new pool complex on the proposed Union St site.
Of those, a slight majority weighed in favour of the cheaper, council-preferred option of $13 million to $14 million for six lanes.
A construction date remains to be scheduled.
