“RETREAT” has been sounded for parts of the Maylands foreshore which is succumbing to dire erosion.
Bayswater council has a new 10-year plan for stabilising the shoreline and retreating some parts, but it’ll need a lot more money; it currently budgets $150,000 per year for the riverbank, but $4.6 million is needed over the next 10 years.
If the works aren’t done, footpaths, gazebos, and countless trees will fall into the river, and the heritage-listed Peninsula Farm is at risk of being undermined.
“Managed retreat” is recommended for the part of the Tranby House Reserve foreshore just north of the farm, with the gazebo’s foundations already exposed as the soil underneath disappears. The footpath will have to be moved inland and the gazebo will have to go unless heroic efforts are made to shore up the banks.
Retreat’s also the plan for part of Claughton Reserve, with a large Katanning tree and park benches to be relocated inland.
Most of the rest of the shoreline will be stabilised with more soil, plantings, and restoring the degraded walls.
Mayor Dan Bull says the problem’s built up over 100 years with “significant change and degradation as a result of dredging, reclamation and human use.
“Now is the time to act if we are to have any chance of restoring this unique ecosystem,” Mr Bull said. “The City has previously worked to protect this area on an as-needed basis. We now know that this is not enough, and what we need to do is set out a long-term, evidence-based approach to find sustainable success in this area.”
Government funding will be needed but councillors decided not to try writing to the state environment minister asking for more money, as council staff advised that “political approach” has been tried repeatedly and hasn’t got them anywhere.
Instead they’ll keep working with the WA conservation department DBCA (which does chip in some money already), show them the 10-year plan, and team up with them to have a better chance when applying for state and federal grants.
Tranby’s woeful score
Bayswater council’s retreat plan comes from a report by consultant MP Rogers & Associates which found the bank along the council’s area has suffered between 5m and 20m of erosion since 1995.
They rated the different areas of shoreline based on a severity system used by the US Army Corps of Engineers.
Each area gets a score for how bad it is from 1 (excellent, no work needed) to 5 (very poor, major work urgently required). That number’s then multiplied by a rating based on how bad the consequence is of not fixing it (1 being minor, 5 being risk of death and irreversible environmental impact), to get a final score anywhere between 1 and 25.
The timber walling and stairs at Tranby House reserve scored the worst possible score of 25, requiring action within the next year or two and estimated to cost more than $1 million to stabilise.
The wall failed years ago and the stairs are damaged, and an “unacceptable risk to public safety. The warning tape currently in place is not a sufficient barrier,” the consultant’s report warns.
Four other sections got “high risk” ratings between 18-21: Maylands Reserve, Hinds Park, Bayswater riverside gardens, and the bit of Tranby House Reserve that’s north of Peninsula Farm.
The report warns rising water levels and an expected increase in boat traffic will only make erosion worse.
By DAVID BELL