David Hamiton, then the Lakes Chair at University of Waikato, New Zealand, has said ‘my great fear is that we now retreat to decide: which few lakes in each region will we seriously try to save?’ This paper explores why Hamilton’s fear is being realised, through the case study of Te Waihora/Lake Ellesmere, a large (19,800 ha), shallow lagoon on the Canterbury coast of Aotearoa New Zealand.
Te Waihora/Lake Ellesmere, long ‘flipped’ into a turbid algae-dominated state, and severely hypertrophic, lies within New Zealand’s fastest growing area, with rapid ongoing urban development and large irrigation schemes supporting intensive dairy operations.
Building on the work of others this paper assesses the failure of collaborative governance and participatory policy making, which was intended to involve government, local communities, and the Māori iwi (tribe) Ngāi Tahu, to control nutrient pollution of Te Waihora and its catchment.
Nitrogen (N) loads to the lake will reach some 5600 t/yr when at equilibrium with the intensified land use. Collaborative community engagement through the Canterbury Water Management Strategy and associated Selwyn Waihora Zone Committee generated a package of solutions ‘more ambitious in scope, scale, and complexity than anything previously attempted in New Zealand’. For all that, these solutions cumulatively aim to reduce catchment N loads only to 4800 t/yr, thought achievable without land-use change
However, to restore the lake’s macrophyte beds, a goal agreed through Te Waihora’s multi-stakeholder co-governance involving all levels of government and Ngāi Tahu, requires reducing the catchment N load to 800 t/yr. Such reductions would end all dairying and irrigation, with significant economic and social impacts. Decision-makers approving Central Plains Water, the largest irrigation project, dismissed such goals as ‘clearly unachievable’. So too has the regional regulator, Environment Canterbury, who fought to have Te Waihora excluded from the national limit setting.
Twenty years’ collaborative governance and multi-stakeholder engagement over Te Waihora and its catchment have resulted in restoration goals but no policies or practices that will remotely approach meeting them. The failure may already be permanent, especially as there is no sign of political appetite for doing more. How and why has Te Waihora, the fifth-largest lake in Aotearoa New Zealand, become a lake we will not seriously try to save?