Rottnest Island's main jetty is riddled with concrete cancer and sinkholes and needs to be repaired as part of a multimillion-dollar upgrade of the island's deteriorating boating infrastructure.
The Rottnest Island Authority's draft boating management strategy, to be released today, says "substantial investment" is needed to ensure "the ongoing integrity" of several island jetties.
The strategy also reaffirms the need for a new marina near the army jetty at the southern end of Thomson Bay to accommodate the growing number of large private yachts crowding into the island's popular bays.
In addition to the deterioration of the main jetty, the strategy said the army jetty was no longer safe for vehicle and boating traffic, the pylons of Stark Jetty in Thomson Bay needed significant repair and the damaged Green Island Jetty had been closed.
The strategy does not outline the cost of the repairs - except for replacing the army jetty for $3 million, which does not include the cost of the marina should it get the go-ahead - but admits that it would be more than the RIA's existing revenue streams. It would require a special budget allocation from the State Government.
The strategy will be released for three weeks of public comment.
RIA chairman John Driscoll said the recent trend towards increased boat ownership and larger vessels would have an impact on the island's marine reserves. Already, about 185,000 of the 500,000 annual visits to the island are made by private or charter boats.
"It is important the RIA determines an appropriate response in the provision of infrastructure and facilities, together with the way access to these facilities in managed," he said.
With demand for new moorings continuing to grow, the strategy said there was potential for more mooring sites only at the southern side of Thomson Bay.
But it said there was little capacity to provide for larger vessels, without reducing the overall number of moorings.
However, the construction of a marina - as proposed in the RIA's most recent five-year management plan - would safely accommodate boat sizes from 5m to 25m and provide facilities for a barge and charter vessels.
The strategy said there were about 500 people on the waiting list for a mooring at a preferred site.