Leslie Harrison Dam

Project details

Fulton Hogan was selected in 2017 by Seqwater to complete the repairs and upgrades to the Leslie Harrison Dam. Following design approvals, construction began in mid-2018 and finished ahead of the 12 month goal in May 2019. The upgrade plan cost $18 million, coming in under the budgeted $24 million for the project.

Background

Seqwater performed a number of dam safety reviews in 2012 – 2014 within South East Queensland. Leslie Harrison Dam was chosen to be a part of Seqwater’s Dam Improvement Program as it supplies about 25% of Redland City’s drinking water.

Requirements

The upgrades for Leslie Harrison Dam were focused on strengthening the dam wall and spillway to improve safety. Features identified within the design included: the widening and strengthening of the dam wall; anchoring the spillway at the crest and the lower end; improving the dam’s resilience to extreme weather events and earthquakes; and modifying the water intake tower to improve flood immunity. Fulton Hogan needed 33,000 tonnes of a specially designed sand to assist with managing seepage and provide support to the structure of the dam.

Our solution

The specially designed sand for this project had to be highly tested for PSD (grading), Density, Degradation, Permeability and Sand Castle to ensure that it was better than compliant based on the specifications.

River Sands provided a 2A Filter Sand which was used to protect the dam from a potential piping failure caused by upstream to downstream seepage from the reservoir through the dam wall.

Our 2A Filter Sand underwent testing prior to the project being awarded, to ensure a better-than-compliant match with the requested specifications.

Source: Seqwater

How we did it

To meet the extensive testing requirements for each batch, River Sands performed several tests within our on-site NATA registered and ISO 9001 Quality Assured laboratory. We also worked with external laboratories to confirm the results and streamline the sampling and approval process for each product batch.

Additionally, we used the space within our sandplant to stockpile approved batches of 2A Filter Sand ready for delivery. River Sands was also able to perform the specialised blending onsite to meet the required specifications.

The benefits

Our efficiency within the manufacturing, testing and approval process guaranteed we were delivering within the time constraints of the project timeline. Our team worked closely with the project site to ensure there was sufficient product throughout the construction timeline, this was greatly assisted by our ability to stockpile approved batches at the sandplant.

By using River Sands products, Fulton Hogan was assured of the quality of the sand and its reputation within the industry from other successful projects. As a result of using our 2A Filter Sand, the Leslie Harrison Dam upgrades will function for a long period of time.

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