Dr Doug Edmeades: Healthy Rivers

Five hundred to six hundred. Now lets put some units on it; five hundred to six hundred million dollars. Now give it meaning; this is the estimated annualized cost of achieving Scenario 1 of the Healthy River Plan in 80 years. Now give it some life; to make the Waikato River swimmable for its full length, in 80 years, will cost a large amount of money. Indeed some are suggesting that these costs could possibly cripple many of the small towns in the region. Goodbye Tokoroa, Te Awamutu, and Cambridge etc.

One gets the same sinking feeling considering the mitigation costs at the individual farm level. Some preliminary data suggests that the costs per farm will lie in the range from nil to $750, 000. Some farmers simply will not survive.

You would think that, given these potentially ruinous costs, we had better be certain that the objectives of the plan will be achieved. But consider the lack of certainty as expressed in the Section 32 Evaluation Report on the plan:

"Whilst technical knowledge of water quality cause and effect is well established precise quantification is not currently feasible. Difficulties include 1) lag effects - time frames for actions on land to create a water quality response and 2) the attribution of water quality response back to individual property-level mitigation actions."

The problem is that science, and this is particularly true of biological sciences, is never complete and certain - there are always unknowns and assumptions.

Given these uncertainties do we really want to run the risk of potentially crippling our local economy for the sake of swimmable water? Noting that doing nothing is not an option, it seems that some compromises are essential and indeed inevitable.

Why do we need, it must be asked, to be able to swim the Waikato River from source to mouth. The Waipa has always been a muddy creek according to some historical accounts. Why not a lesser standard below Ngaruawahia, where the Waipa flows into the Waikato?

The Waikato River catchment has been subdivided into 74 sub-catchments, which have been prioritized, based on their water quality - thirty four are rated as priority 1. Why not concentrate on these high priority catchments first and see where that takes over time in terms of the overall quality in the River?

And why should all the cost fall onto the farmers? Historically the whole Waikato community has benefited enormously from farming over the last 100 years or so. This is reflecting in the historical description that Hamilton was built on superphosphate and milk. Sure, it is roundly accepted that we must now tidy up our environmental act, but let us not forget that many, many urban families, over many, many decades owed their high living standards to pastoral farming.

I can nevertheless hear the shrill, single-minded, single-issue, environmental voice saying: farmers are the cause of the problem therefore farmers should pay the cost for their pollution. Such binary thinking ignores the broader reality that we are all part of the community.

There are other vexatious aspects to the current Healthy River Plan. Consider, there are four contaminants that affect water quality; nitrogen (N), phosphorus (P), sediments and pathogens. The Plan recognizes this and makes it clear that all must be reduced.

Given that this is so, why pick on one, N, as the sole criteria for deciding whether a given farm is a permitted activity or otherwise. We could see farmers who develop and implement farm management practices which greatly reduce P, sediment and pathogens loadings into the river, going out of business because Overseer predicts that the farm is over the limit with respect to the amount of N leaching.

The implication is that, if we control nitrate-N leaching into and through the soil, we will simultaneously minimize water movement across the soil, carrying with it P, sediment and pathogens. The different mechanisms by which these contaminants get into waterbodies, makes this argument illogical.

Furthermore, using nitrate leaching, as predicted by Overseer, as the sole criteria for deciding who can and cannot farm, invites endless litigation as farmers fight for the right to continue farming for their benefit and for the betterment of society.

This invitation is made all the more enticing when it is realized that Overseer is, like water quality science itself, not perfect.

It is, to be fair, a world-class tool for what it was designed to do - what if scenarios - if I do X on my farm what will happen to nitrate leaching. The sole focus is on the trend in nitrate leaching and not on the quantitative amount. The errors involved in Overseer when used to predict nitrate leaching should preclude it from being used in a regulatory setting, other than for simple qualitative analysis as suggested above.

None of the arguments presented above should be taken to mean that I am opposed to the Healthy River Plan. I am not. I accept that doing nothing is not an option. In this sense I am being an Issue Advocate. The issue is pastoral farming - how do we, despite the odds we currently face, learn how to continue farming profitably and at the same time reduce our environmental footprint. I happen to believe we will find a way.

Necessity is the mother of invention