Addaction has secured a grant of £1.55m from the Big Lottery Young People's Fund after it was able to prove to the lottery distributor that its project was 'additional' to statutory spending.
The award, for a therapeutic care programme for 11 to 19-year-olds, will provide intensive support for young people in the community who have drug and alcohol problems - a service available only to young people in local authority care.
Addaction showed how, by providing this support in their own communities, local authorities would not need to send people out of their locality to residential services.
The programme, to be run with Adfam, will support 100 young people each year.
Emily Dunbar, head of fundraising at Addaction, said: "By demonstrating additionality, we have been able to develop a service that will be flexible."