Geological Consulting was engaged by Stantec to assist with the development of a 3D geological model for Burdekin Falls Dam, Queensland. The dam is mass concrete gravity, with a maximum height of around 55m and a crest length of approximately 875m.  It has a central free-overflow spillway, which is around 500m wide.  The geological model was developed to support the design of the upgrade of the dam, which included strengthening and raising.

The geological model was based upon a very large volume of existing information that was available from the original investigation and construction of the dam in the 1980s, and supplemented with further information obtained over the 30 or so years of dam operation.  A key part of the project was mining available information and then digitising this into a useable format, for use in the model.  This included transposing of boreholes into an AGS4 database format.  The model included the 3D as-built details of the existing dam, including the as-built foundation surface, grout curtain and foundation drainage. Foundation mapping was draped over relevant surfaces, which key geological features then included within the model.

As the technical leader for the geology of the project, Geological Consulting was responsible for:

• Defining the objectives of the model.
• Selecting the information that was relevant and should be included in the model.
• Defining the different characteristics of the available data, such as their reliability and accuracy.
• Reviewing what the completed model showed and explaining this to project stakeholders, including key knowledge gaps.