The bags don't cost anything as they are made from recycled materials and volunteers give up their time to construct them.
To make the bags Ron Connell cuts the fabric in bulk at his man cave at home.
"It makes it a lot easier than a lot of girls with scissors trying to cut these out one piece at a time."
He says he doesn't mind putting aside time for a worthy cause.
"I'll just keep cutting as much as they want, I've got time."
The bags are screen printed with boomerang logos - some will have designs created by school kids.
And soon the Boomerang bags will be replacing plastic ones across town.
Z Whitianga manager Luana Tupou says she'll have a clearer conscious handing Boomerang bags over the counter as opposed to plastic ones.
"I mean you get at least a dozen customers a day, they fill up on fuel then they'll grab some drinks chocolate pies, and I mean it's hard enough for them to carry it all out, so they'll ask for a bag."
It is estimated New Zealanders throw away 4.3 million plastic bags every day.
Ms Cohen hopes the project will make people think twice when doing their shopping to preserve the planet for the next generation.
"It's not just having a replaceable bag for the plastic bags, it's educating people on how bad they are for the environment."
The Thames Coromandel District Council wants more ideas on how to reduce waste in the district. Submissions on the issue are welcome until the 8th of May.
Made with funding from