The Tyabb Reservoir is a critical storage point used to meet summer water supply demands for the Mornington Peninsula. A dividing embankment was constructed inside the reservoir to create two independently operating basins. Each basin was lined and floating covers installed. The purpose of the cover and lining is to protect the quality of the drinking water, which comes from Melbourne Water’s Cardinia Reservoir or Tarago Treatment Plant via large water mains. Dividing the basins create a more robust operating network and, along with an improved cover design, reduces safety risks to operation and maintenance crews.