The cost of new water storage for irrigation is far more than just the direct economics, explains Murray Neilson.
Gerrard Eckhoff (ODT, 22.1.18) paints a disturbingly black-and-white picture on the need for water storage and the Government’s perceived lack of appreciation of the economic principles involved with its decision to wind down support for irrigation. In his view there appear to be only two valid uses for water: recreation or production. What of environmental and natural character values? Are these not also worthy uses?
Mr Eckhoff accuses the environmental lobby of "demonising" intensive agriculture. The Cambridge Dictionary defines demonising as: "To try to make someone or a group of people seem as if they are evil."
Rather, the environmental lobby has performed a valuable public service by exposing the true facts of the situation to public scrutiny, thus enabling proper examination of the impacts of intensive agriculture.
The past Parliamentary Commissioner for the Environment commented on this in her 2017 annual report.
"Today water quality issues are reported far more accurately in the media and debates are much better informed."
She had earlier found, in a report on water quality and land use and nutrient pollution, a clear correlation between large-scale land-use change to dairy farming and increases in the nitrogen "stress" on waterways."
In her commentary on the "Environment Aotearoa 2015" report she found the macroinvertebrate community index (MCI – an indicator of ecosystem health) had improved in 29 of the monitored sites between 2004 and 2013, but had declined at 59 sites (a large proportion of which were in Canterbury).
She commented that "Water quality is very good in undeveloped parts of the country, but poor in many catchments. Much of this is a consequence of historic bush clearance on unstable soils and increasingly intensive farming."
Additionally, the Ministry for the Environment, in its "Our freshwater 2017" report found that, of the 175 sites monitored in the pastoral class, nitrate trends were worsening at 61% and improving at 22% for the period 1994 to 2013.
The OECD, in its recent report, Environmental Performance Reviews: New Zealand 2017, reported similar findings.
It had this to say: "Government grants and concessional funding for irrigation projects aim to reduce the vulnerability of pasture-based agriculture to variable rainfall patterns and to enhance water use efficiency. However, they do not systematically consider the environmental and social costs of irrigation, and the benefits largely occur to the agriculture and processing industries."
The OECD recommended the adoption of natural capital accounting, as a result.
The publication of these facts can hardly be described as "demonising" agriculture — unless, of course, these reputable agencies are perceived to be part of the environmental lobby?
Viewed against this background, it is not surprising that the new Government has called a halt to investment in new irrigation schemes.
Turning now to the environmental and natural character values of waterways — topography, including setting and bed-form is important; as are the existence of natural-flow characteristics (i.e. magnitude, rate, timing and frequency of floods, freshes and low flows), natural water colour and clarity, and the ecology of the waterway and its margins.)
For the ecology to succeed, a natural juxtaposition of riffles, rapids, pools and runs is important, along with a plentiful supply of clean gravels, cobbles, and boulders, free of sediment and algae, upon and among which aquatic invertebrates can flourish.
Stable undercut banks, with overhanging vegetation to provide both cover and overhead shade are also important, as are open, braided reaches.
Around three-quarters of our native fish, one-third of invertebrates and one-third of the plants that inhabit our waterways, as well as three species of riverine water-birds, are threatened with, or at risk of, extinction.
Almost half of our native fish species require migratory passage and access to and from the sea.
Water storage large enough for significant volumes of water means most are built in main-stem river valleys.
These cause environmental impacts, including the drowning of river valleys and habitats of vulnerable species.
However, most significant is the prevention or disruption of migratory fish species.
This is technically difficult to mitigate.
National capital accounting, if it comes to pass, will likely show the true costs to the country of building these facilities, rather than just the opportunity costs of not constructing them, as exhorted by Mr Eckhoff.
- Murray Neilson is a trustee of the Clutha Fisheries Trust and an Otago Fish and Game councillor.
