Sydneysiders are consuming more than twice as much cocaine as people in Melbourne and Brisbane, according to the nation's sewers.

In August last year, for every 1000 people, 1.2 grams of cocaine was consumed daily in Sydney, compared with just over 400 milligrams in Melbourne and Brisbane.

NSW is consuming more than twice as much cocaine as Victoria and Queensland. Credit:Jennifer Soo

The figures were revealed in the Australian Criminal Intelligence Commission's most recent examination of wastewater treatment plants across the nation, compiled in partnership with the University of Queensland and University of South Australia.

It is the sixth report of the National Wastewater Drug Monitoring Program, which covers 56 per cent of the population, or 13 million people, and is concluding its second year.