This report has been produced to test potential consequences of setting freshwater objectives for hydro scheme operations. Modelling was undertaken of a selection of various scenarios involving an increase in minimum flows in selected rivers to assess the impact of draft proposals to amend the NPS Freshwater Management on the New Zealand electricity system. The report is not intended to be used for any other purpose. It is noted that:
- none of the modelled scenarios reflect regional council policy proposals
- the scenarios involve hypothetical changes to hydro scheme operations that are not realistic as means to manage the water environment
- the scenarios are used to illustrate the nature and scale of potential impacts, where alternatives to national bottom lines are not available.
The report should be read in conjunction with the 2013 report, Evaluation of potential electricity sector outcomes from revised minimum flow regimes on selected rivers, which modelled scenarios involving an increase in minimum flows in selected rivers, which modelled scenarios involving an increase in minimum flows in selected rivers, to assess its impact on individual hydro schemes and the electricity market.