DSE Home > Coasts and Marine > Publications

Portland Wade Street Landslip - investigation monitoring and analysis of a landslip

In August 2007, two landslips occurred on the cliff face in Portland Bay near Wade St. DSE and Glenelg Shire closed the area and commissioned a report from geotechnical consultants Parsons Brinckerhoff.

The geotechnical report is complete and available below. It assesses short and long term risks to public and private assets and outlines a range of possible strategies for responding to the landslips. There is a high likelihood that more landslips will occur.

DSE is focusing on the very real threat to public safety and will immediately:

• maintain automated and manual monitoring of the landslip
• maintain public safety management of the beach below the slip and the cliff area adjoining the slip
• remove the existing temporary fencing and barriers at the end of Wade St and replace with more suitable permanent fencing
• remove the beach access stairs at Andersons Point.

We will fully consider all options in the report in relation to broader Crown land management policies and risk mitigation implications.

We understand and acknowledge the concern of residents and other stakeholders and are committed to working closely with the community. We will keep people fully informed of any decisions and future works.

Portland Wade St Landslip - Executive summary (PDF - 19 pages, 1.6 MB)

Part 1 - Introduction (PDF - 2 pages, 208 KB)

Part 2 - Site description (PDF - 3 pages, 313 KB)

Part 3 - Summary of site management (PDF - 8 pages, 653 KB)

Part 4 - Desk study (PDF - 10 pages, 862 KB)

Part 5 - Geotechnical investigation (PDF - 9 pages, 815 KB)

Part 6 - Monitoring (PDF - 7 pages, 650 KB)

Part 7 - Preliminary stability analysis (PDF - 9 pages, 838 KB)

Part 8 - Risk assessment and remedial works (PDF - 6 pages, 571 KB)

Part 9 - Concepts for remedial engineering works (PDF - 3 pages, 309 KB)

Part 10 - Recommendations for further works (PDF - 4 pages, 369 KB)

Appendix A - Location plan: Portland (PDF - 2 pages, 135 KB)

Appendix B - Plan view of Wade Street slip (PDF - 2 pages, 158 KB)

Appendix C - Plan of key slip features (PDF - 2 pages, 161 KB)

Appendix D - Photos: September 2007 (PDF - 8 pages, 496 KB)

Appendix E - Photos: June-November 2008 (PDF - 7 pages, 464 KB)

Appendix F - Site plan: Instrumentation and geological cross-section transects (PDF - 2 pages, 232 KB)

Appendix G - Emergency response plan (PDF - 18 pages, 878 KB)

Appendix H - Borehole logs and explanatory notes (PDF - 28 pages, 2.5 MB)

Appendix I - Geological cross-sections A to E (PDF - 6 pages, 239 KB)

Appendix J - Laboratory testing results (PDF - 29 pages, 2.3 MB)

Appendix K - Rock core photographs (PDF - 2 pages, 132 KB)

Appendix L - Site monitoring station (PDF - 3 pages, 188 KB)

Appendix M - Vibrating Wire Piezometer installation details (PDF - 5 pages, 274 KB)

Appendix N - Inclinometer profiles (PDF - 3 pages, 137 KB)

Appendix O - Ground surface monitoring results (PDF - 13 pages, 942 KB)

Appendix P - Extensometer results (PDF - 5 pages, 195 KB)

Appendix Q - Vibrating Wire Piezometer results (PDF - 5 pages, 215 KB)

Appendix R - Rainfall results: Bureau of Meteorology - Portland station (PDF - 3 pages, 167 KB)

Appendix S - Rainfall results: Site Monitoring Station (PDF - 2 pages, 101 KB)

Appendix T - Contour data supplied by Glenelg Shire Council (PDF - 2 pages, 103 KB)

Appendix U - Site clinometer profiles (PDF - 5 pages, 325 KB)

Appendix V - RocLab analysis (PDF - 3 pages, 199 KB)

Appendix W - Model calibration for colluvium (PDF - 3 pages, 184 KB)

Appendix X - Slope geometry calibration for colluvium (PDF - 3 pages, 131 KB)

Appendix Y - Slope stability analysis: existing slope assessment (PDF - 2 pages, 113 KB)

Appendix Z - Slope stability analysis: existing slope - assessment of groundwater level thresholds (PDF - 3 pages, 179 KB)

Appendix AA - Conceptual option 1: sketches of remedial works (PDF - 3 pages, 243 KB)

Appendix AB - Conceptual option 2: sketches of remedial works (PDF - 3 pages, 213 KB)

Appendix AC - Conceptual option 3: sketches of remedial works (PDF - 3 pages, 223 KB)

Appendix AD - 12 month future works program (PDF - 2 pages, 176 KB)



If you are having trouble downloading these documents or you would like to receive them in an accessible format, such as large print or audio, please telephone 136 186, 1800 122 969 (TTY), or email customer.service@dse.vic.gov.au