Landslips can be caused by many different factors including falling boulders, fast flowing water and debris, to large and slow moving landslips involving entire hillsides. Approximately 5,000 households in the Yarra Ranges are located in landslip prone areas.
Landslips can be triggered by heavy rainfall and artificial concentrations of water such as:
- Irrigation of horticultural land
- Aqueduct failure
- Relocation of water courses
- Poorly designed stormwater run-off
- In-ground wastewater disposal
Blackwood Avenue Landslip
The Blackwood Avenue Landslip lies on the north bank of the Yarra River in Warburton. Cumulative movements up to 1.5 metres have been measured on Blackwood Avenue in the last decade. There is concern that this landslip could block the river and cause flooding in the Warburton area.
The landslip covers about six hectares and is an irregular shape and has a maximum length of about 320 metres and a maximum width of about 230 metres. It has an estimated maximum thickness of about 15m, based on the geometric considerations. The height difference from the top to the bottom of the landslip is about 80m. Natural slopes adjacent to the landslip are about 12 to 14 degrees.
The Blackwood Avenue Site Specific Landslip Contingency Plan provides more detailed information. Click on the link for more information on this site.