The League of Victorian Imagineers received the award at a ceremony in the Opera House last night and will now represent Oamaru at the 2010 national awards in the Western Bay and Tauranga districts next March.
TrustPower community relations representative Melanie Tavendale said the League of Victorian Imagineers put together some vibrant community events in Oamaru that captured the imagination of people across the country.
Record numbers of people attended New Zealand's first Steampunk exhibition at the Forrester Gallery.
Since then, the group has been highly visible on social networking sites and gained national media coverage, leading to the recent Steampunk Fashion Parade and Gala Ball.
"All types of people are getting behind this movement, and Oamaru has quickly become the Steampunk capital of New Zealand."
The quirky Victorian science fiction genre had taken off all over the world, and the forward-thinking Oamaru group had really led the charge, Mrs Tavendale said.
Waitaki Mayor Alex Familton believed the awards partnership between TrustPower and the Waitaki District Council gave valuable financial support and recognition to volunteers.
For the supreme award, the League of Victorian Imagineers received a framed certificate, a trophy, $1500 and a six-month subscription to Fundraising in New Zealand magazine.
It will be filmed by a TVNZ6 crew to feature in a new series called "Volunteer Power".
Last night, groups received a total of $5350 in awards.
This year 46 nominations were received.
Other winners were: Heritage and environment: The League of Victorian Imagineers; runner-up, Totara Estate Volunteers.
Health and well-being: Salvation Army Family Store; runner-up, Age Concern Waitaki.
Arts and culture: Oamaru Repertory Society; runner-up, 45 South TV; commendation, Oamaru Operatic and Musical Society.
Sport and leisure: Oamaru Rowing Club; runner-up, Vintage Car Club of NZ North Otago branch.
Educational and child-youth development: Waitaki Community Gardens; runner-up, St John Youth.