Arihia was appointed to her current position in 2012 and has had a long career in health and social services since 1979. From 1981-2005 she worked for Child, Youth and Family, during which she took six years out to work in the tourism sector including Ngāi Tahu Tourism.
In 2006, Arihia was appointed Regional Manager Te Waipounamu for Barnardos New Zealand, a position that she held for five years. Following this and prior to taking up her current position, Arihia was Kaiārahi/Chief Executive Officer of He Oranga Pounamu, an organisation mandated by Ngāi Tahu to organise and integrate health and social services in the Ngāi Tahu rohe (tribal area).
Arihia has held advisory positions to government, including Canterbury Earthquake Recovery
Comissioner (CERC) following the September 2010 earthquake.
She has held governance roles associated with Te Rūnanga o Ngāi Tahu, including Ngāi Tahu Development Corporation, where she was a Director from 1999-2002, and then Chair until 2005.
In 2008 she was made a member of the New Zealand Order of Merit for services to Māori and the community.