Synlait's announcement of an $82 million deal with Chinese dairy company Bright Dairy has some worried Canterbury's delicate water systems will be pushed to breaking point.

The Synlait deal comes on the back of massive dairy expansion in Canterbury.

Labour Party water spokesman Brendan Burns is worried the Synlait expansion could happen before new environmental controls are put in place.

“It doesn’t matter whether the capital comes in, in the form of yuans, or British pounds or Australian dollars – the net effect on the environment is the same.

The Government wants this growth, it’s building an election strategy around rapid economic growth, but it’s doing nothing to put any new environmental controls in place to manage this growth.

"No matter how well the dairy industry tells us it’s going to manage this growth, its track record is very poor.”

Dr Green Party co-leader Russel Norman says new water quality data from the Ministry for the Environment paints a dire picture of our streams and rivers, and intensive dairying is a major offender.