The RMA can take into account the effects of climate change yet there is no responsibility to mitigate carbon emissions and their potential contribution to the acceleration of climate change.
This contrasts with other countries including the UK, where it will soon become a mandatory requirement to measure, manage and reduce embodied carbon in construction projects.
One of the reasons for this is the lack of true cost accounting, namely the inclusion of often overlooked (but inherently important and potentially very costly) environmental and social factors. Ecological economics and analysis that goes beyond profit and loss, cost benefit ratios and GDP is slow to become part of the analytical and strategic frameworks of our government departments.
The Ruataniwha Dam's construction phase involves large-scale use of carbon-intensive material and transportation of these materials using fossil fuels. It is estimated that 37,500 cu metres of concrete will need to be manufactured and transported together with 2.5 million cu metres of rock and alluvial material.
As well as the dam construction there is an estimated 200km distribution system with pipes or canals requiring considerable earth disturbance and loss of vegetation. Furthermore, hedges and shelter belts are removed to make way for pivot irrigators as farming areas are intensified.
Within the reservoir decomposing vegetation discharges carbon dioxide, methane and other greenhouse gases. The World Commission on Dams highlights this effect and the National Institute for Space Research estimates that "dams are the largest single anthropogenic source of methane, being responsible for 23 per cent of all methane emissions due to human activities" as released from reservoir surfaces, spillways and downstream.
The dam operation and pumping for the pressurised water distribution system requires huge energy resources. Originally the hydro power to be generated by the RWSS may have contributed to offsetting a small portion of this energy use but now this has been deferred to a possible retrofit in the future.
The agricultural and horticultural expansion associated with the scheme will produce more nitrous oxide (another greenhouse gas). Fertiliser accounts for the majority of this emission but could possibly be reduced with better management.
The accumulated gravel will require a very large number of truck loads to "replenish" the coast.
Eventually there will be the decommissioning of the dam and the removal of accumulated sediment. An end-of-life scenario has not been clarified but 75 years seems to be the figure mentioned and will require an equivalent carbon debt to deconstruct and mitigate the environmental damage.
This is a relatively short life span in ecological time yet the carbon embodied through its construction and deconstruction is huge.
More importantly it has created reliance and dependency rather than helping us with long-term resilience (the capacity to deal with stress caused by environmental change) and adaptation to a changing climate.
The opportunity for improved land and water use that respects the carrying capacity of the land and its rivers and allows us to live within the planet's environmental boundaries will be lost.
Jenny Baker is a Napier resident and was a submitter to the RWSS Board of Inquiry.
