Cleaning waterways takes a village

Debate around the Government’s new target to clean up our rivers and lakes has focused on the definition of ‘‘swimmable’’, and whether people are still going to get sick from ‘‘swimmable’’ water. This is important but also runs the risk of missing another point. The real issue is whether the standard can be achieved, even by the seemingly far-off target date of 2040.

On the face of it, the standard doesn’t sound very aspirational. Environment Minister Nick Smith says it will make rivers and lakes the cleanest they have been since World War II, promising $2 billion of Government spending and requiring 54,000 kilometres of fencing to keep stock out of waterways. But the time frame is 23 years, so the national effort will be really a modest average of $87 million a year.

In the meantime, the damage continues and freshwater quality is likely to get worse before it gets better, because of contaminants already in the environment. In Canterbury, more than 170,000 hectares were converted to dairying between 1996 and 2012. The Parliamentary Commissioner for the Environment has made the connection between land use changes and the declining water quality, because of increased use of nitrogen-based fertilisers and urinary nitrogen from more cows on farms. E coli, campylobacter, salmonella, cryptosporidium and giardia from cow faeces can also make their way into water.

A 2014 ECan survey of 325 Canterbury wells found 8 per cent had unacceptable nitrate concentrations. There was enough data from 205 wells to describe a 10-year trend, and nitrate levels had increased in 69, or a third of them, over that decade. On the surface, in addition to long-standing problems in Lakes Forsyth and Ellesmere, warnings were in place this week because of phosphorus and nitrogen-fuelled toxic cyanobacteria at sites along the Opihi, Selwyn, Waihao, Te Ngawai, Hurunui and Cust rivers.

These are the issues behind the Government’s new water quality benchmark. It has defined ‘‘swimmable’’ water as having less than 540 E coli bacteria per 100 millilitres for 80 per cent of the time, rising to 90 per cent by 2040. Critics claim that people will have an 80 per cent chance of getting sick in a ‘‘swimmable’’ river at that level of contamination. Smith ripostes that this is ‘‘junk science’’ because it is assuming the upper limit is the median, and in fact the actual chance of sickness will be closer to one in 1000.

The dispute diverts attention from what is really at stake – not an argument about E coli levels or how clean the water was in World War II, but what needs to be done to clean up rivers and lakes, simply because it is the right thing to do.

Farmers, often pilloried under the convenient slogan ‘‘dirty dairying’’, are on the front line of this effort. Under measures such as the Clean Streams Accord of 2003 and the Sustainable Dairying Water Accord of 2013, more than 24,000km of waterways nationally have already been fenced off from stock. Farmers have been busy bridging or culverting fords, working to reduce nutrient losses and planting along riverbanks. They should be supported in this.

Defining ‘‘swimmable’’ water is merely setting a benchmark, and the argument about it is distracting. The actual work to improve water quality is complex, difficult and inter-generational.