Coastal Management

Coastal Management

Following the completion of the port works in May 2015, Department of Transport (DoT) has the ongoing responsibility for the performance of the reconfigured coastal structures. DoT will provide yearly updates on the monitoring and proposed maintenance works.

PGLOA has a vested interest in coastal management, not only because it is the key signature of our precinct, but more importantly, because Port Geographe landowners are in part financing these activities through the SAR  contribution to the Waterways Management Reserve Fund. This vested interest is even more heightened by the fact that the extent of the designated Port Geographe Coastal Management Area (PGCMA), to which we are contributing, extends well beyond the SAR catchment zone.

The 2015 Update by DoT noted the much improved natural by-passing in the first winter, and can be viewed on the Departments website.

Notwithstanding this, in late 2105 DoT undertook a substantial sand-trucking and deposition program on Wonnerup Beach, euphemistically called “nourishment”.

As an involved stakeholder, PGLOA is on the DoT mailing list, and has received the 2016 Update – which is not yet on the DoT website. This describes the continued good performance of the reconfiguration, but notes an accumulation of sand and seaweed in the port entry channel requiring immediate dredging. The 2016 Update also calls for a further small sand “nourishing” program for Wonnerup Beach, but states that the western beach be left alone for another winter season.

The PGLOA Committee considers the eastern side of the Port Geographe Marina (that is Wonnerup Beach) should also be left alone, to enable the coast to settle down and the littoral drift to do its job. At present there is no evidence of erosion but only small pockets of sand “starving”.

It is well documented the Wonnerup beach profile has historically experienced seasonal losses and gains of sand, well before the Marina was built. The apparent effects of “erosion” in the 2015 winter relates to overfilling of the beach.

PGLOA believe it un-necessary to further add “nourishment” to the beach

profile in this area, only to have it taken away by the prevailing long-shore drift. The beach profile here is slowly coming to equilibrium.

We recommend the situation be further assessed after the third winter, before any further works are contemplated.