Rottnest Island is one of Western Australia’s premier tourist attractions and welcomed over 823,000 visitors in 2024. Visitor numbers are increasing to Rottnest, which strives to balance environment values with increasing visitation, many of whom stay on the island overnight.
Established under the Rottnest Island Authority Act 1987, Rottnest Island Authority (RIA) is a statutory body responsible for the management of Wadjemup / Rottnest Island on behalf of the WA State Government.
All development and major infrastructure works on Rottnest Island are guided by the Rottnest Island Management Plan 2023–2028, shaped by public consultation, and governed by legislation and external regulations including the Environmental Protection Act, Heritage Act and Aboriginal Heritage Act.
Martin Marerwa, the Director of Infrastructure for Rottnest Island, says this has presented a unique set of challenges ranging from environmental, cultural, financial and logistical.
As the jewel in the crown of Western Australian tourism, The State Government is investing in a cleaner energy future for Rottnest Island, targeting 75 per cent renewable power. A hybrid energy system and upgrades to the desalination plant are reducing carbon emissions, supporting long-term sustainability.
“We have undertaken a staged process to focus on sustainability in terms of utility provision with power generation and the water supply being synchronised through the installation of a hybrid system,” says Marerwa.
“Infrastructure provision on the island is about working with environmental requirements and getting the balance right between the built and natural environments.”
One of the major projects has been in power generation, and moving the Rottnest micro grid away from a reliance on diesel generation and towards wind and solar, and abating around 14,000 tonnes of carbon emissions annually.
The proposed system is expected to include a mix of renewable energy solutions including solar, wind and battery storage together with diesel generation. Final configuration decisions will be guided by engineering design and required statutory approvals.
The other significant infrastructure issue on Rottnest is water, and the island has long relied on a desalination plant for its potable supply in addition to treating its own wastewater.
The water supply infrastructure upgrade program has $67m funding and upgrades are being carried out progressively, with a new Desalination plant expected to be commissioned in 2026, increasing the island’s production capacity to up to 1500 cubic metres a day.
Delivering these infrastructure upgrades presents a significant logistical challenge, as there is only one form of construction material delivery access through a contracted barge service.
Stakeholder consultation and management is a key priority as more businesses offer accommodation and other services on Rottnest to provide for the growing number of visitors.
“Early stakeholder engagement is a part of the process of determining the feasibility of a solution,” says Marerwa.
“The business community on the island is significantly invested in the delivery of the infrastructure. Projects also have statutory requirements for public consultation as part of the approval process.
“It all means we are pretty much in partnership with all stakeholders in determining the best solution for the island.”
Martin Marerwa will be presenting on Sustainably Delivering Key Infrastructure on an A-Class Reserve as part of the Public Works Stream at IPWC 2025, to be held at ICC Sydney from 25-28 of August
