Overflow from the Hinemoa Street pumping station started at 6.34pm 8 July, and stopped at 1.21am, 9 July.
Council's environmental health officers will be inspecting the areas for any visible signs of contamination, and warning signs have been erected advising against swimming in, or fishing from the stream.
Water quality testing is currently being undertaken.
For further information, please contact: David Tu, Environmental Health Officer
on 04 5706 779