Gravity fed stream water is one of the major sources of water on the Island. Water is sourced at a higher elevation and then travels down a pipeline to either a storage tank, or in some case, straight to the tap. Depending on the size of the water supply and the care and consideration taken when laying the line,stream water can be a good source of non-drinking water. A good idea is to use stream water for your larger water uses, gardens, toilet water and so on, and to have a rain water supply for your drinking and cleaning needs.
Although the Island still has a relatively clean water supply at the higher altitudes there are health problems with stream water, especially during summer as the water temperature rises both in the streams and pipelines. This is a main concern of the Local Board with Aotea Health recommending:
The Health Team encourage all those drinking (or using water that enters the mouth) to do so from a rain harvested system. Unfortunately all stream water on the island is considered contaminated from a health perspective.
A gravity fed water system also takes some maintenance. The line can be washed out by floods, air can enter the pipe causing air locks, over time sediment can build up in the pipe and slow or halt the flow of water, and if there is no top filter eels can get trapped in the line. Some of these problems can be overcome by good planning.
Stream water cost example
A example of a stream water supply with a small tank.
1 x 200m of 25mm Enduroflex LDPE.
1 x Hydroflow ES25 25mm Stainless Steel filter.
Female Straight Coupling
1 x Hansen HFS25 Female Straight Coupling.
1 x Hydroflow PP25 25mm Ball Valve.
Male Straight Coupling
2 x Hansen HMS25 Male Straight Coupling.
1 x 1725L Aquatank water tank.
1 x Irritec filter with 130 Micron poly mesh.
Last updated on the 06-04-2020