File photo. Photo: 123RF
An investigation into Timaru's discoloured drinking water has found discharge from silage pits was the likely cause.
Residents experienced several weeks of yellow and brown water over the summer period, although no drinking water health standards were breached.
The Canterbury Regional Council said tests at the time showed the colour change was due to elevated concentrations of manganese.
Council director of science,Tim Davie, said testing had showed silage was a likely contributor to the discolouration.
He said the area would continue to be monitored and all silage pits near or within drinking water protection zones across the region were being reviewed.