Counties Manukau District Health Board is short 150 nurses, a revelation the New Zealand Nurses Organisation is calling outrageous.
The shortages were highlighted during the parliamentary health select committee's annual review of the DHB yesterday.
Chief nurse Jenny Parr said it was a problem as the DHB tries to juggle staff working in managed isolation facilities, while the country's closed borders restrict access to overseas workers.
"We do have a number of additional nurses that are working in our managed isolation facilities so that does have a constraint around our ability to get casual staff when there's a need."
But she said the DHB has a vacancy rate of less than 5 per cent for its 3200 nurses and said staff turnover had been significantly reduced since the country's borders have been shut.
However, New Zealand Nurses Organisation manager of industrial services Glenda Alexander said such workforce shortages are having an impact on nurses working in hospitals.
"That's why we have members reporting that they are stressed and overwhelmed," Alexander said.
"It takes its toll because they are tired and working extra shifts to make up for the shortages. It's the whole compounding effect of it, which impacts on their health and well-being.
"It's outrageous that it has that number of vacancies. But it's not surprising," Alexander said.
"We know there are huge numbers of nurses we need in the workforce that just aren't there."
She said the union has been working with DHBs to try and improve staffing levels in the health sector.
But Alexander agreed with Parr's comments about the impact of the pandemic on nursing.
"One of the things contributing to the number of vacancies is the border closures, because we've been relying on internationally qualified nurses to supplement our workforce."
She said the profession also has an ageing workforce, with many existing nurses reaching, or close to, retirement age.
During yesterday's select committee hearing, Counties Manukau DHB chief executive Margie Apa agreed staffing shortages were a major issue for the whole health sector.
It followed comments from National MP Simon Watts who asked how the DHB could provide much-needed services if it doesn't have the workforce to deliver them.
"We do have a national work programme that the DHBs as a collective are working on with the Ministry of Health jointly to understand our [workforce] pipeline."
Counties Manukau Health's battle with staffing shortages isn't new. In September 2020 it was revealed its Mental Health and Addiction department had a staffing shortage of 121 positions.
It came at a time when demand for such services was high because of Covid-19, with people facing greater financial strain due to unemployment, limited ability to cope with new norms and the fall-out from family violence.