They believe their proposed changes would present a range of additional opportunities to further benefit the community and the region's economy.
These could include the opportunity to host national water polo, swimming and surf life saving pool rescue championships, and a range of regional events.
What they propose could also attract international events, they say.
Their letter spells out a range of further opportunities.
They believe their proposals would generate millions of dollars of additional revenue for the district into the future.
The Government has put up $40 million for the project under the Covid-19 recovery fund's “shovel ready” programme.