He was responding to questions about the impact of changes that may result from the "Putting the Patient First" report that noted a lack of cohesion among existing Dunedin services and the need for a new patient-focused vision.
Mr Rousseau said the governance group's report showed the board could not just continue in a cost-cutting mode as that was now having an even greater negative impact on staff morale and services than before.
This was not a new issue, but there was now a much greater recognition that investment would be required "to ensure we can continue to provide really good services", meet the minister of health's targets and build sustainable services.
Mr Rousseau said he felt in most areas the board provided really good services.
"The difference today versus last year and the year before and the year before that is that the work that the National Health Board are doing is supportive of this investment requirement."
Previously the position had been the board needed to be more efficient and then use those savings to invest.
The National Health Board has been undertaking an assessment of Dunedin Hospital systems and is expected to announce its resulting recommendations next month.
At this month's hospitals' advisory committee meeting, chairman Paul Menzies asked questions about the "reasonably slow" progress towards shared clinical services in the region, suggesting that more than a year after the merger of the two boards, more had been expected.
Member Tim Ward asked whether the board was "getting too far ahead of ourselves" to be expecting consistency across the region in services or would services always be "site specific".
Otago chief operating officer Vivian Blake said there would always be some differences relating to the volume and types of cases treated at each site.
However, getting consistent prioritisation criteria and booking systems should be quite simple.
Southland chief operating officer Lexie O'Shea said the management team had been working together a lot longer than the medical staff.
One of the issues was finding time for senior staff from both major hospitals to meet.
"We're asking the clinical team to do this on top of their day job as well".
