[ctman]

Dams aren't impervious to killing lots of people either: http://en.wikipedia.org/wiki/Vajont_Dam http://en.wikipedia.org/wiki/Banqiao_Dam

2 incidents in 15 years: 175,000+ killed. Plus they emit methane in huge quantities (from the decay of plant materiel in the reservoir)

I would bet that for New Zealand the best form of energy would be geothermal even though the long-term effect studies around cooling the earth's crust are lacking.