Project Aqua impact on Waitaki Valley climate
For immediate release: Tuesday, 12 August 2003
Little impact on lower Waitaki Valley climate as a result of Project Aqua
The Project Aqua hydro electricity scheme would have only very minor and localised effects on the climate within the lower Waitaki Valley.
Project Aqua is a proposed hydro electric scheme with a 60km canal and six power stations along the south side of the lower Waitaki Valley. It would have the capacity to produce 524 megawatts of renewable electricity.
“Meridian Energy commissioned a detailed expert report on the effects of Project Aqua on the climate within the lower Waitaki Valley, which concluded that any changes as a result of the operation of Project Aqua would be relatively minor and localised,” says Meridian Energy spokesman Alan Seay.
The report forecasts a slight increase in relative humidity and a slight decrease in the day-night temperature range (amounting to less than 0.20C), restricted to within a few tens of meters near to the canal. The climate impacts report – Project Aqua Assessment of Environmental Effects Appendix Y – was prepared by scientists at NIWA and the University of Otago.
Fog may become more common in autumn and winter within 500m of the canals. Localised areas upslope from canal embankments are likely to experience up to 12 percent more frequent frosts during winter (of up to 1.20C heavier), says the report. This effect will be most marked near the embankments, but in places may extend upslope by several hundred metres.
Over-all, the climate effects are forecast to be small and localised, and mostly related to cold air being held up by canal embankments. This would affect only areas upslope from the southern side of the canal embankment.
“The minor effects that have been forecast would not be expected to significantly impact on existing or planned agriculture or horticulture within the lower Waitaki Valley,” says Mr Seay.