North Pine Reservoir Roof Structure




After more than 40 years in the ground, the drinking water reservoir at the North Pine Water Treatment Plant was showing its age. Groundwater had started to seep through the bitumen membrane and concrete roof, leaching into the reservoir—potentially contaminating the drinking water supply.

Pensar was engaged to excavate the reservoir roof and expose the concrete substrate, repair the concrete roof joints and build a new steel-framed roof structure. Central to Pensar securing the project was the solution to use small, lightweight excavation equipment to remove the topsoil covering the reservoir—a fast, efficient and economical alternative to vacuum technology. In the process, Pensar also designed and constructed a stormwater drainage system and installed bird proofing.

Seqwater’s objectives for the project were to provide a further 50 year lifespan and eliminate the risk of untreated water entering the reservoir. Pensar successfully delivered the project within budget and within Seqwater’s critical timeframes, meeting all technical specifications, and without compromising drinking water supply.




North Pine Water Treatment Plant


August – December 2013




  • removal of 2500 m3 topsoil
  • 2000 m concrete joint repairs
  • construction of 13 500 m2 structural steel roof
  • design & construction of stormwater solution
  • installation of 3500 m2 bird proofing

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