Under-aged drinking is a problem in Murray Bridge, a landmark survey has shown - and the whole community will need to be part of the solution.
More than a quarter of the 131 respondents to a Planet Youth survey, all year 10 students, said they had been drunk within the past month.
A similar proportion said they felt pressured to drink alcohol within their friendship group, and that they first drank it at age 13 or younger.
But those who spent more time with their parents were less likely to get drunk, smoke or use cannabis.
Public health expert Alfgeir Kristjansson presented the survey's findings at a workshop in Murray Bridge last week.
The city's council was already planning how the community could respond, Mayor Brenton Lewis said.
A central coordination point for young people in need of support, mentoring at sporting clubs and extra arts and cultural activities were among the ideas floated, he said.
"Creating projects to limit risk factors and increase protective factors are fundamental parts of the Planet Youth model, which takes into account local needs, aiming to empower as many young people and parents as possible," he said.
"Gathering and interpreting local data ... are only the first steps in a longer journey."
Factors which concided with higher rates of drunkenness included friends who drank, parents who did not care if they got drunk, a lack of parental supervision after 10pm, and use of social media for more than three hours per day.
Less-supervised teens were twice as likely to use cannabis regularly; all cannabis users said their parents disapproved of the drug.
Several respondents said they had already used substances such as cocaine or ecstasy, or opioid drugs without a prescription.
The survey also found far lower rates of participation in sport and other activities in Murray Bridge, a higher number of teens who thought their school work was boring or pointless, and a lower number who said they wanted to keep living in the district.
However, the survey did make some encouraging findings.
The rates at which local adolescents drank alcohol, got drunk, smoked cigarettes or used cannabis were slightly lower than in other Planet Youth regions across Australia: the Limestone Coast; Blue Mountains; Lithgow, New South Wales; and Sydney's inner west.
Fewer locals reported having got drunk or tried cigarettes or cannabis at a young age.
Surprisingly, no-one reported using laughing gas - more commonly known as nitrous oxide, "nossies" or "nangs", and known to be used within the community.
About nine out of 10 teens said their parents knew their friends, showed they cared about them and helped with their school work.
They also painted a picture of a community in which their parents were more likely to know their neighbours, and in which neighbours were more likely to intervene if they saw young people graffitiing, fighting, breaking into property or being rude.
The Planet Youth approach to solving social problems, through data collection and population-wide prevention efforts rather than just education in schools, was pioneered in Iceland in 1999.
At the time, more than half of Icelandic 10th-graders smoked and drank.
The rate of substance use there is now among the lowest in Europe, and juvenile crime and bullying have also reduced.
The initiative is being trialled by Murray Bridge's local drug action team under the federal government's National Ice Action Strategy and the Alcohol and Drug Foundation.