Posted on September 22, 2025
The Western Australian Department of Transport and Major Infrastructure (DTMI) will extend the northern breakwater at Jurien Bay Boat Harbour by 170 metres to tackle recurring water quality problems linked to seagrass accumulation.
Jurien Bay Boat Harbour provides berths, fuelling, maintenance facilities and a four-lane boat ramp. The facility also serves as a gateway to nearby reefs and the Jurien Bay Marine Park.
Located 220 kilometres north of Perth, the harbour faces seasonal challenges when seagrass decomposes in the waters during winter and spring. This process depletes oxygen, creates a strong odour and has occasionally caused fish deaths.
Over the past decade, DTMI has conducted research including dredging trials, trawling and bubble curtain tests. Modelling showed that the breakwater extension would divert about 80 percent of seagrass from entering the harbour, reducing fish kills and improving water quality.
Breakwater extension planned at Jurien Bay Boat Harbour. Transport WA
Construction will involve importing rock by trucks and earthmoving equipment to build the spur groyne. Dredging works are also scheduled for late 2025 to clear seaweed and deepen navigation channels.
A project update on 18 September 2025 confirmed that the reconfiguration is expected to reduce the need for frequent dredging and support future leasehold development within the harbour.
