Recent events relating to water quality and quantity in this country should raise considerable awareness of the value of H2O to our health, welfare and productive economy. But are they? In an ODT article in 2013, I mentioned that "while always considered to be a valuable commodity (especially within Central Otago), water can no longer be regarded as an unlimited resource for general consumption".
Escherichia coli and campylobacter are ubiquitous in our environment, particularly where animals are raised and human waste is treated. From there it is a short hop into our water supplies, as Havelock North discovered recently and other local authorities may yet experience.
South Island rivers and lakes have several well-established pest species, in particular Lagarosiphon major and Didymosphenia geminata. Now "lake snot" (Cyclotella bodanica) is proving its tenacity in adhering to fishing lines and blocking water filters in iconic Lakes Wanaka, Wakatipu and Hawea, and may be a considerable biosecurity threat to other high country lakes.
The Guardians of Lake Wanaka have been impressing the changing ecology of the lake on authorities for several years and, in March 2013, hosted a seminar, "Lake Wanaka — For Better Or Worse? Planning For The Future". Expected outcomes from that seminar included:
● Sharing information on national programmes, research, monitoring and control efforts and reviewing relevance to Lake Wanaka.
● Identifying how further research, improved monitoring or specific control programmes could benefit Lake Wanaka and other deep water lakes.
● Establishing priorities, responsibilities and sources of funding for new or expanded initiatives.
The Guardians, Niwa and Otago University scientists have struggled to obtain recognition of ongoing deterioration of Lake Wanaka water quality despite success in the fight against Lagarosiphon. Communications and proposals to develop a deepwater lakes management plan have been sent to the ORC, QLDC and the Environment and Conservation ministers. That management plan, supported by comprehensive annual monitoring, is long overdue and the current research regime is sporadic and barely adequate.
Where is the promised further consultation on submissions to the MFE’s "Next Steps for Freshwater" document, intended to amend the National Policy Statement for Freshwater Management? Political wheels turn very slowly and, even if immediate management systems occurred, it may take decades to fully regenerate water quality in Wanaka’s 33 cubic km of water.
Who to blame? Causal actions of aquatic pollution are prevalent in both our urban/industrial environments and our ever intensifying rural landscape. Nationally, we need to heed anecdotal information and scientific research indicating our aquatic environment is under stress, largely from anthropomorphic activities. Damage repair will be inter-generational and the cost to society substantial. As temporary custodians of this land, we must think long and hard about meaningful protection and future-proofing of our water supplies and associated resources.
Restorative attention should focus on protection and improvement in the management of tussock grassland catchments. We must promote innovative economic means of retaining pastoral farming while constraining further deterioration of indigenous high country shrub and grasslands, as now being practised via QEII covenants at Robert Lange’s Soho Properties (ODT, 3.9.16).
Managing productive pastoral run country in a manner that maximises vegetation biodiversity and tussock regeneration, encouraging canopy growth (shading hawkweeds etc), will conserve water supplies. With unpredictable global climate shifts now being felt, tussock grasslands form a critical component of Otago’s water-harvesting capability on which the majority of our intensive low country land-use ultimately relies for irrigation, as do urban areas for potable water.
Irrigation projects, the lifeblood of rural economic development, need careful planning to prevent over-utilisation, something currently causing consternation over setting of minimum flows for local rivers like the Lindis. Canterbury Plains aquifers have experienced over-allocation and Otago also has high potential for that. Hopefully, a balance can be reached between quantity of extraction as defined by ORC’s integrated water management plans, while retaining water quality as invoked by Plan Change 6A. How, or if, the proposed 15kg/ha/year maximum nitrogen input for lake catchments will be achieved and its effect on nutrient assimilation within Otago’s deepwater lakes remains questionable.
We have reached a tipping point: technology enabling industrial and land management systems to outstrip their basic resource supply, particularly water. Regionally (and nationally) we must redefine the true value of water to local communities. It is easy to become blase when the Clutha Mata-au River passes our back doorstep with a mean flow of over 600 cubic metres per second, while more than 40% of Otago’s total area is now under some form of urban or primary productive land use (excluding pastoral grazing country).
Water is a valuable natural resource which, managed wisely and sustainably within clearly identified environmental limits, offers significant potential for future economic stability.
Good practice now will prevent local authorities implementing strict rule-based controls and avert substantial social and financial costs to reverse damage to our aquatic ecosystems and their catchments.
- Dr Barrie Wills is an environmental research scientist, Central Otago district councillor and Guardians of Lake Wanaka member.
