Dr Clark confirmed $20 million of Crown funding and the site for the new Buller Health Centre.
He said the latest concept design had been accepted, allowing detailed design work to proceed.
"The people of Buller have waited long enough for a modern, purpose-designed health facility,'' Dr Clark said.
"The Government has listened to the public engagement process and the typically direct feedback from Coasters, including input from the clinicians who will work there.''
The facility will be located on the current hospital site in Derby St.
The scope of the project will be increased to allow for the inclusion of the locally provided adult dental service as well as two additional medical beds.
West Coast-Tasman MP Damien O'Connor, who was in Westport with the minister, thanked Dr Clark for listening to feedback and boosting the number of medical beds beyond the initial plan.
"Many people should be proud of their efforts to get a better deal for Buller residents after the previous government's determination to penny pinch and entirely ignore the community's wishes,'' Mr O'Connor said.
"The new facility will be one that the community can be proud of, and I'll be keen to see construction get under way as soon as possible.''
The previous government had set a budget of $12 million. As with the new Greymouth hospital, the $20 million is a loan which will need to be repaid.
Yesterday's announcement comes after years of grassroots campaigns in Westport for a bigger facility, including a protest march and hands around the hospital.
The new health centre will have 12 beds, instead of the planned 10.
The new facility has been talked about since 2011, but went on the backburner once the new Greymouth Hospital got under way.
