Water pollution in the West Coast region

[5] The water on Lake Brunner has been monitored since the 1990s and its quality has remained relatively high, although there are concerns about the effects of significant pasture drainage from local dairy farms.

[6] North of Westport Water from the Stockton open cast coal mine pollutes the Ngākawau River.

It took a concerted effort on the part of local environmentalists to get the regional council to insist on the farm installing effluent ponds.

These ponds then largely discharged into the river via a drain for many years, and were washed out during floods until a particular complaint in 2016 got the regional council to insist on an upgrade, and a shift to above the floodline.

There has also been extensive land use change over the last decade on this farm, where 60ha or more of forest remnants/ wetlands have been destroyed for humped and hollowed pasture.