Ngarimu is currently the Deputy Chair of the Ngati Whatua Orakei Trust and their appointee to Whai Rawa Ltd which is a large commercial entity. He is also a Director of Manaaki Whenua-Landcare Research and a Governance Board member for an MBIE National Science Challenge, ‘Building Better Houses Towns and Cities. He serves as a Director of the North Harbour Rugby Union and the New Zealand Maori Rugby Board. He is a Director of the Sir Peter Blake Trust and a Co-Chair of the Mana Whenua Kaitiaki Forum which represents x19 tribes of the wider Auckland Region. He is a guest lecturer in a number of departments across The University of Auckland and AUT on Auckland Maori history, planning and media issues.