Contingency planning meetings have been held regularly since the Lakes District Health Board received notice of the planned nurses' strike.
There are eight hours of strike action by the New Zealand Nurses Organisation planned for Wednesday, June 9.
In a statement, the DHB said contingency planners were working closely with managers and clinical leaders on "ensuring the continuing provision of essential emergency services including acute surgery, emergency department care, intensive care, and maternity care".
The strike is scheduled to start at 11am and finish at 7pm, meaning it will cover two nursing shifts.
All elective surgery cases and nearly all outpatient clinics are being deferred for the day of the strike. Those people whose procedures and appointments are being deferred are being contacted individually by the Lakes DHB.
Contingency planner Nina Hartley said staff were focused on trying to reduce the number of patients in the hospital in the days leading up to the strike, but the winter conditions and pressures were expected to make this difficult to achieve.
She said any decisions made about impacts on services are being taken to allow clinical staff to focus on those in most need.
"Arrangements are being made to ensure anyone needing essential medical care will get the help they need, but we cannot underestimate the impact of this strike."
The strike action will involve a complete withdrawal of labour by members of the New Zealand Nurses Organisation. About 730 nurses are currently employed by Lakes DHB, with many of them members of the union.
While all elective procedures are being postponed, a small number of nursing staff are on call to allow for emergency surgery to proceed.
Only urgent cases will be able to be dealt with at the emergency department at Rotorua and Taupō Hospitals during the industrial action.
The DHB is urging people to make sure they are up to date with their prescriptions and other requirements, and if they get into difficulty, they should make their GP or Lakes PrimeCare their first port of call.
People with minor health issues should visit their family doctor or Lakes PrimeCare, and need to realise that the Emergency Departments at both Rotorua and Taupo Hospitals are for emergencies.
Emergency and essential services will be available and people should not delay seeking medical treatment or going to the hospital if the matter is urgent. They should dial 111 for emergencies or an ambulance.
People can call Healthline free on 0800 611 116 for health advice and information. The service is available 24/7.
Lakes DHB very much appreciates the support and help from health staff across the sector.