The Dunedin City Council said it had been in touch with Port Otago to discuss restrictions brought in last Tuesday after dry conditions.
Those restrictions applied to households in Port Chalmers, Waikouaiti, Karitane, Hawksbury, Roseneath, Careys Bay and Sawyers Bay.
The port implemented its own restrictions on water it supplied to cruise ships, a council spokesman said.
Vessels would only be supplied water "if the need is urgent while our water restrictions remain in place".
The Otago Daily Times asked the council about the situation with cruise ships after the subject was raised amid discussion about water restrictions on a Port Chalmers Facebook page.
Port Otago is a commercial customer for the council and is metered for its water usage, including that supplied to cruise ships.
During normal operations, the port accounts for about 2% of water usage in the Port Chalmers area.
This could increase significantly — to between 20% and 30% — when water was provided to cruise ships, the council spokesman said.
This did not happen every time a cruise ship visited Dunedin, he said.
The port was conscious of the need to conserve water, given conditions.
Dunedin City Council Three Waters acting group manager John McAndrew spoke last week about what level 1 restrictions meant for residents in the East Otago or north coast area affected.
"Outdoors, we ask people to minimise the watering of their gardens where possible, and to avoid anything that uses a lot of water — like using garden sprinklers during the day, washing cars or water-blasting", he said.
"Indoors, we recommend shorter showers and not using running water to brush teeth or wash vegetables.
"The rest of Dunedin’s water supply is also getting low, and with mostly dry weather forecast for the next month, we are reminding all residents and businesses in the Dunedin area to work together to make sure we’re not using more water than necessary."
Port Chalmers water comes from the Rossville Reservoir and from Dunedin’s water supply.
The reservoir was particularly low, and dropping, the council spokesman said on Friday.
The council’s 2021-31 long-term plan included $14 million to increase water supply capacity from the Dunedin metropolitan system to Port Chalmers.
"This will involve decommissioning the two raw dams and water treatment plant at Port Chalmers, used only to service cruise ships in summer, and install a new water supply pipeline from the Mount Grand treatment plant to Port Chalmers."
However, the West Harbour Community Board argued the Cedar Creek and Rossville dams were important to the resilience of West Harbour communities.
This led to the council acknowledging the level of community interest in the future of the dams and treatment plant, and saying there would be community engagement before decision-making about this.
"Longer-term options for how best to supply water to Port Chalmers are still being considered", the council spokesman said on Friday.
