Read more: Waiariki strike decision due today
"I have worked with Cathy Cooney in her past role as the chief executive of Lakes District Health Board and as a consultant leading change projects. She displays a considered approach which is measured and constructive," Mrs Chadwick said.
She added Ms Cooney brought great skills to the job and Rotorua could be proud of her appointment.
Ms Ohia and Mr Turner are members of the Bay of Plenty Polytechnic Council and Mr Turner is the chairman. Ms Tahana is a member of the Council of the Waiariki Institute of Technology.
Mr Joyce said they would keep those positions until the disestablishment of those two councils on May 1.
"I want to acknowledge the important contribution that these three council members have made in bringing together the two institutions."
"All four of the new appointments are effective immediately. The appointment of members from the existing councils provide continuity and the new chair will bring fresh insights."
Mr Joyce said he had staggered the terms of appointment for the council and, so he could review two appointments after completion of ongoing consultation with iwi of the region, he had appointed Ms Ohia and Ms Tahana for one year each.
Mr Joyce said the next stage in creating the new institution was the appointment of the remaining council members.