Heavy rain has caused sewage spills in Auckland and Whangarei, prompting a health warning for the public.
Whangarei District Council says both its pumping stations overflowed following a downpour on Thursday.
Northland Health says people should not swim upstream of Waikaraka for the next week and avoid eating shellfish from there for a month.
It says downstream of Waikaraka, where the contamination is more diluted, it should be safe to eat shellfish again after a week.
In Auckland, the public was warned not to swim at local beaches until Sunday.
Auckland City Council says heavy rain early on Friday may have caused stormwater and sewage to spill into the sea.
