Dr Daniel Collins is a hydrologist at NIWA. He formed the Waiology blog to bring together commentary on New Zealand's freshwater systems. The blog features commentary from numerous contributors.

How much water does NZ have? - Waiology

Jun 08, 2011

By Daniel Collins The amount of water that falls on New Zealand each year is about 560,000 million m3. Lumped together as ‘precipitation’, this is mostly rain, but also snow, hail and even some graupel. That’s enough water to cover the country 2.1 metres deep, or to fill Lake Taupo over 9 times. More than most countries, but not all. How much of this precipitation makes its way to the sea, instead of evaporating along the way, is less clear. This number is important because it tells us about how much freshwater is available to the environment and us. The most commonly cited report to date, released by Statistics NZ, puts this at about 79%, but there is good reason to believe this estimate to be on the high side. A study published in 1972 reported 72%. Read More

Why Waiology? - Waiology

Jun 02, 2011

By Daniel Collins Water (‘wai’ in te reo Maori) is one of NZ’s most precious resources. We drink it, we eat food grown with it, we power our homes and businesses with it, we play in it, and we are mentally and spiritually uplifted by it and by what it brings. But despite being relatively water-rich on an international stage, what we want from this water outstrips what we actually get. If you follow the news, it’s easy to see how. Droughts in Northland and flooding in Hawke’s Bay… calls for more dams, or for fewer… water restrictions and high electricity prices. It’s a long list of recurring themes that more or less affects us all. And regardless of whether you’re a farmer or kayaker, resource manager or engineer, the more you know the … Read More