Simpson said those who tested positive were put into a negative pressure area, which removed them from general areas and meant the situation could be managed with appropriate precautions such as PPE gear.
"We need to ensure all the other people attending (hospital) are kept safe.
"There has already been a number who have attended for treatment of Covid-19 but have been discharged without needing to be admitted.
"If the modelling plays out in the next two to three weeks then we are likely to see more requiring hospitalisation for Covid-related illness. As I've said many times before though, no model is a perfect one.
"We may or may not follow the scenarios that have been mapped out."
The Ministry of Health announced 209 new cases of Covid-19 in the Whanganui District Health Board region on Monday.
The total number of active cases now stands at 1629, with 1858 recovered.
There have been 3487 cases of Covid-19 in the region since the pandemic began.
New Zealand had 14,463 new cases on Monday, according to the ministry.
There were 1000 people in hospital, with 33 in ICU.
Nine Covid-related deaths were reported.
The ministry says its daily reported cases may differ slightly from those reported at a DHB or local public health unit level.
This is because of different reporting cut-off times and the assignment of cases between regions, for example when a case is tested outside their region of residence.
In terms of current daily case numbers, Simpson said they had been reasonably consistent to this point.
"If it stays where it is I'll feel pretty comfortable. We've planned for these numbers."
A significant spike would place huge pressure on all of the DHB's resources, however.
"Whanganui Hospital has four dedicated negative pressure areas that can accommodate four patients at any one time," Simpson said.
"If we admit 15 or more patients with Covid-19, this will trigger our Level 4 response.
"The Level 4 response involves the opening of a Covid-dedicated ward where all Covid -positive patients will be cohorted together."