Civic Exchange on Tuesday urged the government to come up with a more ambitious plan for increasing the city's own supply of water.
They say existing plans – which involve introducing desalinated water, reclaimed water, harvested rainwater and treated grey water – aren't aggressive enough, won't make local supplies more resilient to climate change, and don't lower the city's reliance on imported Dongjiang water.
Natalie Chan, a senior adviser with the think tank, said this is an issue that needs more attention.
"Actually we are not experiencing water shortages as in the 1960s. That's because we are importing close to 70 percent of the fresh water that we need from Dongjiang water," Chan said.
"But without this imported water, we'll be with our buckets down there collecting water for our day to day use. So we feel that it's important for us to be conscious that water is actually a scarce resource."