Sally Malay Water Storage Facility

Client: Roche Mining for Kimberley Nickel Mines
Location: Sally Malay, WA
Start Date: April 2004
End Date: July 2004
Value: $2 million

Sally Malay mine is located in the East Kimberley region of Western Australia, 240km south of Kunnunurra.

This project involved the construction of a Water Storage Facility in steep and rocky terrain comprising:

• Clearing and stripping topsoil to 5.8ha of reservoir area;
• Borrow, moisture condition, transport, place and compact 35,000m³ material for Earth and rockfill dam consisting of an earth core rockfill embankment;
• Chimney filter;
• Spillway and associated earthworks; and
• Site rehabilitation.

This involved precision earthworks and high compaction standards. Permeability was critical as the dam was upstream of the Bungle Bungles.  The degree and rocky nature of the slopes provided a real challenge for workers especially during installation of the chimney filters. 

Several bore holes, encountered during construction of the keyway, allowed underground water to inundate the area under construction.  Controlling flow and grouting holes was necessary to proceed with the clay core for the reservoir wall.  With limited suitable clay material in nominated borrow pits the project team had to devote time and effort to sourcing, testing and conditioning sufficient material to complete the core.

The contract required almost 30,000 tonne of aggregate to be crushed for both dams including 7000m³ crushed material for chimney filters.  The construction team took great care in handling the filter material to prevent segregation, voids and contamination with surrounding material.