To help protect the integrity of Cape Town’s water supply, a floating cover on the Neptune Reservoir near Simons Town was removed and replaced. The reservoir was built in 1940 and a floating cover installed in 1989. The water quality had deteriorated over time due to high concentrations of pollen deposited in the reservoir by the wind.
The reservoir has a 55 Ml capacity, 112.6 m diameter and 6 m wall height. The old cover, a combination of Hypalon and HDPE, was replaced with a 1.14 mm thick reinforced flexible polypropylene (RFPP) floating cover.
The reservoir interior was also lined with a 2 mm thick linear low-density polyethylene (LLDPE) liner to prevent leakage via ageing expansion joints. New seals were fitted to valves and pipework intersecting the liner and a leakage detection system installed beneath the liner.