Water pollution in the Canterbury region

Due to the rain shadow effect of the Southern Alps the rainfall in Canterbury is lower than many other parts of the country at 500–700 mm per year.

Nitrate concentrations in the groundwater are above the drinking water standards in around 7% of monitored wells according to 2017 data from Environment Canterbury.

The estuary where the two rivers discharge had received treated water from the sewerage treatment plant that processed the city's sewage.

A large number of resource consent applications for intensive dairy farming in the Mackenzie Basin attracted opposition due in part to the potential effects on water quality.

[7] The Dairying and Clean Streams Accord was set up by Fonterra and a number of government agencies as a means of reducing nonpoint source pollution.

Farm Environment Plans require farms to plan and demonstrate they are actively managing environmental practices such as nutrient application, erosion risk, irrigation, dairy effluent and waterway protection (through fencing off waterways in intensively stocked areas and riparian planting).