Most households in New Zealand have water supplied by the local council. This water is transported to households through pipes and is known as reticulated water. Depending on where you live, reticulated water will have come from either surface water sources such as lakes and rivers, or from underground aquifers.
The water in our lakes and rivers originally falls to the earth’s surface as rainwater or snow. The region over which this water naturally flows into a particular waterway such as a lake or river, is called a catchment. Some of this water will also be held back by dams, where it is stored until it is needed.
Water from lakes and rivers will have some contamination in it from dirt, decaying vegetation and animal waste, as well as chemical elements it will have absorbed from the land around it. This water needs to be treated to quality standards set out by the Ministry of Health. Once treated the water is stored in reservoirs, where it is pumped to households as required.
Moving the water from the catchment area to your tap uses energy. Treatment plants, reservoirs and tanks are usually put on high ground to make the most of gravity in moving the water. However pumps are used to pull the water up from aquifers, and in some cases it’s just not possible to use gravity to move water, and it needs to be pumped up hills or through steep areas.
Aquifers are another source of water for households. Aquifers are underground rock formations which store water. Much of Christchurch’s urban water supply comes from aquifers.
Image source: Watercare Services Limited
Not all New Zealanders rely on town supply for their water. About 10 percent of the population, (mostly living in rural or coastal areas) are on their own individual water supply systems - these are either private rainwater tanks or bores (wells). Rainwater tanks and water bores are the responsibility of the rural property owner who also arranges testing and treatment of the water as required.
Water supplied to urban households often travels long distances to get there. Whereas water used in rural areas for irrigation is usually drawn from underground bores or nearby rainwater tanks. There is less energy and expensive infrastructure, such as underground pipes, needed to get the water where it needs to be.
