Thursday, October 05, 2017

Fencing streams is just a PR stunt

Whenever they are criticised over the amount of shit and piss they pump into our rivers, dairy farmers whine about how much money they've spent on fencing streams. Except it turns out that this fencing is utterly ineffective, because the vast majority of pollution enters waterways through streams below the fencing threshold:

More than three quarters of pollution flowing into our freshwater catchments comes through small streams that currently aren't required to be fenced off, a just-published study has shown.

The study's authors say new measures should be investigated to slash the amount of contaminants entering waterways from these streams, while Fish and Game has called for an "urgent and radical rethink" of our current national riparian fencing strategy.


Streams less than a metre wide and 30cm deep, and lying in flat, pasture-dominated pasture, are currently exempt from fencing regulations.

Yet McDowell and his colleagues found it was these very bodies that accounted for an average of 77 per cent of the national contaminant load, varying from 73 per cent of total nitrogen to 84 per cent for dissolved reactive phosphorus.

Which makes perfect sense, because most of the water comes from such streams, before being gathered into larger ones. But it means that we need to look at other policies if we want to reduce pollution. And ultimately, we need to reduce cow numbers to sustainable levels.