It is to make sure pumps in the city's drinking water network can keep the reservoirs filled and water flowing.
"We need enough water for emergencies and firefighting purposes, particularly as hotter weather also increases the risk of fires," she said.
"Reservoir levels are being monitored daily and weather forecasts closely watched."
Restrictions are usually imposed at the start of summer, and not lifted until some time in autumn.
For more information about alert levels and Napier City Council's watering regime you can visit the website: napier.govt.nz #restrictions.