A wastewater overflow has impacted the harbour at Matua.
Tauranga City Council said tree roots had damaged a sewer line causing a wastewater overflow at Tilby Drive and Fergusson Park.
The council said contractors were currently on site clearing the blockage, however the overflow had impacted the harbour.
Warning signs will be in place to alert the community between Kiriwai Pl and Kulim Park and water quality testing will be undertaken, but the council is taking a precautionary approach that the discharge site will be affected.