Migrating sand dunes pose potential risks to roads, homes and infrastructure

While the report – Migration of Limesand Dunes in Western Australia and Their Impacts – has just been released, the information has already been presented to a number of State and Local Government agencies.

DMP Project Manager Mike Freeman, a key contributor to the report, has stressed that mobile dunes move very slowly over many years, but could cause serious problems if not monitored and kept in check.

“The dunes start on beaches and when pushed by prevailing winds, they migrate almost parallel to the coastline before petering out and becoming stabilised, especially when vegetation grows over them,” Mr Freeman said.

“However, in the meantime, large quantities of sand can blow over areas including roads, railway lines, houses and recreational areas, with indications some sand dunes have migrated more than 20 km.

 “After issues arose with the grant of mining tenements over the mobile sand dunes, a decision was made to undertake a strategic research project to learn more about them, such as how fast they migrate, the direction in which they migrate and which dunes threaten our built infrastructure.”

DMP collaborated with Josefine Bruch from Dresden University in order to understand the long term impacts of 19 migrating dunes in the Mid West which were perceived as presenting possible future problems.

The report identifies four key dune impact risks:

• At Green Head North in the Shire of Coorow, a dune has closed a coastal tourist access road, forcing the Shire to build a replacement road that is now facing a long-term threat from the dune.
• A dune that has encroached on Kailis Drive in the Shire of Irwin is being cleared from the road but the main “wave” of the dune is yet to arrive.
• In the City of Greater Geraldton, a dune south of the City is threatening to cut the Brand Highway and cover houses in the suburb of Wandina.
• A large dune is approaching Indian Ocean Drive near the community of Grey and has the potential to cover and block the highway.

DMP has presented the information and engaged with Local Government authorities in the Mid West, including the Shires of Gingin, Dandaragan, Coorow, Carnamah and Irwin, and the City of Greater Geraldton.

DMP has also engaged with a number of State Government agencies including the Departments of Planning, Parks and Wildlife and Food and Agriculture, Main Roads WA and the Midwest Regional Development Commission.

“DMP wants to spread the message that the State and Local Government bodies that manage the lands on which mobile sand dunes occur, should be monitoring the dunes on an ongoing basis and assessing the likely serious impacts of migration”, Mr Freeman said.

“We all need to be aware of the issue, how it affects planning and start considering how to address the impacts of dune migration.”