Rain Water

Rainwater TanksRainwater harvesting is a simple way of utilising a natural resource. Using your roof as a catchment area, the rainwater is collected in a storage tank or tanks for later use. The Island has an abundance of rain during the winter months and the periodic rains during summer are enough to keep a household going throughout the year depending on the size of their storage. It is clean, easy to collect, hygienic, and used by 65% of households on the Island for their drinking and washing water and half of all households to water their gardens as well.

Rainwater can have its problems though. If you live downwind of a dusty road the dust will be caught in your catchment area as well. This also applies to salt spray and, if you have overhanging trees, leaves. There are solutions to alleviate this problem with “First Flush” diverters. The diverter catches the first 20-25 litres of water off the roof and stops it entering your water tank. This is a good idea even if you aren’t near trees, the road, or the sea as it can help preventing bird droppings from entering you water system.

Because rainwater comes from the roof, there is also the problem of water pressure. If there is enough power then a water pump can be an option but many households use a dual system of storage where there is a main collection tank and then, either on a raised platform or a higher part of the property, a header tank. This enables the household more control on when power is being used and also a more constant header pressure which is a must for forms of water heating such as califonts..

Rain water cost example

An example of a rain water system including guttering.


10 x 5m lengths of Stormcloud Spouting.


Spouting brackets

84 x brackets for the spouting.



7 x 80mm Marley Classic downpipe.


Pipe Clips

14 x RC80 pipe clips.


Socket Bends

2 x 95 degree RB2.80.


Welding Solvent

1 pot of Welding Solvent.


Water Tank

25210L Aquatank water tank.


Header tank

5020L Aquatank water tank.



30m of 25mm Enduroflex LDPE.



1 x 25mm Hansen HS25 straight coupling.


Reducing bush

50 x 25mm Hansen HRB5025 reducing bushes.


Hex Nipple

1 x 25mm Hansen HSN25 hex nipple.


Ball Valve

1 x Hydroflow PP25 ball valve.


Straight Coupling

1 x 25mm Hansen HMS25 Male Straight coupling.


Long Bend

1 x Hansen HMBL25 Male Long bend.



1 x Irritec filter with 130 Micron poly mesh.


Water Pump

1 x Ozito Petrol Transfer Water Pump 2.2HP.


First Flush diverter

1 x First Flush diverter.



Including GST.



Barriers building supplies specialists.

Ph:09 4290 466

Great Barrier Plumbing & Drainage

Certified Plumber, Drainlayer, and Licensed Gasfitter.

Ph:09 4290 298
Mob: 027 429 0298

Retrofit Your Home now includes rain water systems for GBI.

Last updated on the 06-04-2020