Will the Tukituki get better?
Tom Belford
July 3 2014
Maybe. Maybe not.
The Board of Inquiry (BOI), in its final decision, appears to think it has rescued the Tukituki.
It has required Farm Environmental Management Plans (FEMPs) in which farmers must commit to how they will meet specified
nutrient (nitrogen) leaching limits deemed acceptable for their soil conditions (as indicated by the so-called LUC
system). Farmers will need to use farming practices that best enable them to meet the limits.
In turn, the cumulative nutrient load in the river (measured most critically in terms of dissolved inorganic nitrogen,
DIN) associated with all farming cannot exceed 0.8 mg/L. This compares to DIN limits of 0.44 mg/L set for the
Manawatu-Wanganui and Otago regions. So it’s a good limit, not the best.
This limit – opposed by HBRC – was accepted by the BOI on the basis of evidence from environmentalists, who argued that
the overall biological health of the river ecosystem was already harmfully affected by current nutrient run-off in the
river. HBRC had argued for significantly higher nitrogen limits based on a more narrow measure – fish toxicity. The
higher HBRC limit was seen as an enabler of farming intensification in the catchment (i.e., an enabler of the dam).
That the BOI accepted the case for a DIN limit is a victory for the health of the Tukituki.
Some measuring points in the Tukituki catchment presently exceed the 0.8 DIN limit; some do not. In its own
calculations, the BOI considered that a small amount of ‘headroom’ for more nitrogen in the river presently existed and
therefore the DIN limit was not unduly harsh.
The individual on-farm leaching limits and the overall catchment DIN limit are intended to work together. As the BOI
sees it:
“Effective nitrogen management requires a two-pronged approach. The first component involves the setting of on-land root
zone leaching limits which will serve as an important control at the source of the leaching process (the fence at the
top of the cliff). The other component involves the setting of in-stream nitrate-nitrogen and DIN limits which will
serve as a check as to the effectiveness of the LUC leaching rate control.”
Will this approach improve water quality in the Tukituki?
Environmental advocates believe the on-farm leaching limits will ultimately need to be ratcheted lower and embedded in
consents in order to meet the DIN limit … and that the DIN limit itself might need to be lowered.
In its final decision, the BOI seemed to anticipate that outcome, saying:
“It is the responsibility of HBRC to avoid the exceedence of DIN limits in the receiving water by regulating the level
of nitrogen discharged at the root zone by the farmer and monitoring subsequent DIN concentration in the receiving
water. If observed DIN levels are too high then future adjustment by HBRC of the LUC root zone leaching rates may be
required.”
And further, in its reasoning for not now setting a lower/tougher DIN limit, the BOI says:
“As water quality science advances a different DIN limit may emerge as a more appropriate level. In the meantime the
Board sees the DIN limit of 0.8 mg/L as a pragmatic level that appropriately protects ecological health while enabling
more intensive land use.”
But can we, as the “pragmatic” BOI hopes, both have our cake and eat it too? Or has the BOI simply pushed back the day
of reckoning when we finally actually decide whether, as Councillor Rex Graham says, “It’s time for farmers to adapt to
the river instead of the river adapting to the farmers”?
In all likelihood, if the BOI-ordered regime stands (at this writing, the involved parties have 10 more working days to
file legal appeals), sooner or later the Regional Council will have the same political hot potato back on its hands.
If the DIN limit is exceeded a few years down the road, environmentalists will argue for ratcheting down the on-farm
leaching rates, as the BOI foresees. But the HBRC, if it maintains its historic and current mindset, can be expected to
say: NO, we can’t do that … we’ve already built a dam and farmers have borrowed millions to irrigate and intensify. We
must raise the DIN limit instead … or better still, toss that approach entirely, and switch to more accommodating fish
toxicity limits.
Surely, you say, that’s not a possibility. Hasn’t the BOI, having studied the matter for over a year, definitively
ordered a regime based on DIN limits?
Yes, they did. But, for all practical purposes, the BOI is already history. The political wheel is already turning.
Today, the Government announced its new National Policy Statement for Freshwater Management (download here). It’s a wimpy disappointment, as expected. And what measure does this NPS adopt for assessing and protecting water
quality – fish toxicity! Exactly what the BOI rejected.
So stay tuned folks, the Tukituki ain’t getting better yet. And that’s without the farming intensification a potential
dam will encourage.
The BOI might well turn out to be a minor bump in the road — mere road kill — for the dam juggernaut.
ENDS