Multiple slips and erosion in the upper reaches of catchments across the region are washing sediment into local rivers and estuaries causing them to discolour, the Bay of Plenty Regional Council says.
The council said there had been an average of 200 per cent of normal rainfall over the first three months of the year at sites it measured, meaning that catchments were receiving around twice as much rain as usual.
The council’s compliance team leader, Trudy Richards, said after rain events, the council’s Pollution Hotline often received reports of sedimentation or discolouration of streams, rivers, and estuaries.
“Our team investigates reported incidents to locate the source of the sediment, assess the environmental impact and whether there is any non-compliance,” Richards said.
“Since early January, we have been receiving reports of the Ōmanawa River running dirty.