Geologia Croatica, Vol. 71 No. 2, 2018.
Professional paper
https://doi.org/10.4154/gc.2018.08
Protecting the Karst Te Waikoropupū Springs in New Zealand
Donald James Mead
orcid.org/0000-0002-0438-4326
; Lincoln Unversity (retired)
Abstract
The sacred Te Waikoropupū Springs are New Zealand’s largest, have some of the clearest freshwater worldwide and are a major tourist attraction. They are part of a large karst system, the Arthur Marble Aquifer complex of 180 km2 that has two main interconnected aquifers which have mean residence times of 10.2 and 1.2 years, respectively. The Springs have a high water clarity of 63 m, due to the action of biofilms and stygofauna in the aquifers; to protect this water clarity it is recommended that the level of NO3-N in the Springs should not exceed 0.4 mg/L. In the aquifers’ unconfined zone there are 45 km2 of lowland, free-draining gravels that receive over 2000 mm/a rainfall. The intensification of dairy farming on these soils has resulted in the Springs NO3-N rising to above this trigger concentration of 0.4 mg/L. Three processes, in order of effectiveness, are being considered to control farm impacts on water quality:
1. Dairy farmers have volunteered to stop cattle having direct access to waterways, to manage their dairy-shed waste better and to plant narrow riparian strips. There is some evidence this has reduced farming impacts to waterways.
2. The second method, promoted by the local regional council, is to have stakeholders, assisted by professionals, to recommend water allocation and water quality guidelines for inclusion in their regional plan. This method is ongoing. However, it could be captured by special interest groups and the rules could be relaxed over time. Consultation with the local indigenous Iwi (tribe), who have strong spiritual values for water, is essential.
3. To afford the strongest protection a local Iwi, Ngāti Tama, and Andrew Yuill have applied for a Water Conservation Order (WCO) on the Springs complex and aquifers. This is allowed for in New Zealand law, would provide the strongest long-term protection and, when granted, has to be implemented by the Council.
A very recent, but untested, alternative would be to give the waterbody personhood (legal status equivalent to a human), to be managed by guardians. This has been done for one New Zealand River.To protect the aquifers, the WCO, which offers the greatest control, is recommended.
Keywords
water clarity; nitrate; dairy farming; environmental protection; conservation order
Hrčak ID:
202976
URI
Publication date:
21.6.2018.
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