Australians use more than 13,000 kg of illicit drugs every year, a report has found.

The fifth report of the National Wastewater Drug Monitoring Program, released by the Australian Criminal Intelligence Commission (ACIC) on Tuesday, revealed that Australia ranked second highest for stimulant consumption among 23 countries with comparable data.

It found that Australians used 8,300 kg of methylamphetamine, 3,000 kg of cocaine, 1,200 kg of MDMA and 700 kg of heroin in the 12 months between August 2016 and August 2017.

Michael Phelan, chief executive of ACIC, said that Australians were suffering from organized crime through the illicit drug trade.

"Transnational serious and organised crime groups profit from importing, trafficking, manufacturing and selling drugs," he said in a statement on Tuesday.

"Wastewater analysis provides a measure of the demand for a range of drugs. This allows governments to effectively direct resources to priority areas and monitor the progress of demand and supply reduction strategies."

While methylamphetamine was the most-consumed illicit substance, alcohol and nicotine remained the most popular substances of the 12 measured by ACIC.

The report revealed that consumption of fentanyl, an opioid used as pain medication, was at the highest level since the program began with consumption in regional areas doubling between April 2017 and April 2018.

"While fentanyl consumption measured by the program reflects both licit and illicit use, increased consumption is of concern as the high potency of fentanyl greatly increases the risk of overdose," it said.

ACIC analyzed waste water from 47 treatment plans nationwide, accounting for 54.8 percent of the population.