Blue plastic water tank

Submitted article from Deb in Wellington.


NZ is on a fault line, and Wellington particularly is vulnerable to earthquakes. Periodically those in “power” tell us what we need to do to prepare for that eventuality. The industrious and responsible among us will have had an emergency kit ready for years. The more lackadaisical and procrastinating types probably haven’t got round to it yet.

 Water splash

The one thing we have done in our household is making sure we have a backup supply of water. Not a huge amount, but we have about 100 litres, which would last us maybe 3 days.

One issue is that the Wellington water pipes are in terrible condition and if we get cut off from the rest of the North Island, we might not have water for way more than a few days. According to Wellington Water, it might take up to 100 days to get the supply back to some areas.

So part of our “prepping for just in case the world goes to hell in a hand basket” project has been thinking about how we can collect our own rainwater and have a somewhat larger backup supply.

This post covers some of the options we’ve found for collection, and part 2 will be about how to store and use the water safely.

People with lifestyle blocks or on farms will already have large tanks for this purpose, but we’re perched on the side of a hill, and the only bit of flat land we have is about at the level of our roof. And besides, we just converted most of it into a food producing garden.

So I’ve been researching some other options.

How much water might you need?

Some ballpark figures to help you figure it out:

  • Wellington City Council estimates non-commercial water consumption at an average of 220 litres per person per day, overall uses. The pic below is from one of their handouts.
  • For drinking, cooking, and basic hygiene, WCC recommends storing 20L per person per day, for a minimum of 7 days. [If you were unlucky enough to be in an area that took 100 days to get supply back, and had no way of collecting rainwater, that’s 2000L per person you’d want. Yikes. But that’s the worst-case scenario, and kiwis are resourceful.]
  • Showering takes approx 9.5 L per minute
  • Running your garden hose for an hour uses up to 400 litres, depending on water pressure.

Water usage chart

Before you buy

Check out the regulations in your area.

Info from WCC on installing water tanks, including whether you need consent can be found here.

Short answer:

  • Outdoors = check for your area, but prob not
  • Indoors, eg if you want to plumb the water back into the house = yes

Here are some examples of 

Above Ground Tanks

smaller tanks. There may be other options, or they may be available from other suppliers.

200 L – from the Tank Guy

The Wellington City Council have sourced the bulk of these 200L tanks at a discount, so they are available to buy for a very reasonable cost (about $115), and you don’t need a huge space to put them in. They can be hooked up to collect rainwater, or if that’s not possible, you can fill them from the mains. They are:

  • H 1200mm W 650mm
  • Easy to transport (fit in the back seat of most cars) and simple to install
  • Food grade, UV-resistant plastic
  • Fittings are included
  • Available in dark green or as pictured
  • Can be linked together but would need to buy extra hardware

They can be purchased from:

The Tip Shop Landfill Road Owhiro Bay which is open from 9 am to 4.30 pm daily

Ringing ahead to check if they have stock, or to order, is recommended.

If you’re not in Wellington, visit The Tank Guy website. Other sizes and shapes of tanks are also available.

800 L

  • 1970mm high x 770mm wide.
  • Tall, slim design allows an easy fit into tight spaces
  • Can be linked together for combined attenuation and retention setup
  • Tank-grade plastic. 10-year warranty
  • Built-in leaf strainer and lid unit
  • Includes one tap and bungs
  • 1x 15mm BSP fitting at bucket height for a tap
  • 2 x 32mm BSP fittings at the base for tank-to-tank, and tank-to-pump connection

Available from WaterSmart or from the Tank Guy.

1000 L – FenceTank

  • Dimensions: 1800mm high x 1800mm long x 408mm deep.
  • Slimline water retention innovation
  • Naturally blends with your property
  • Quick and easy to install.
  • They do NOT require a concrete base. Just 4 coach screws attached to a fence post.
  • Can be attached to a fence or free standing.
  • Connects together to increase volume.

Available from WaterSmart.

1000 L – stormPANEL  [& 2000 L on its way]

stormPANEL stormwater tanks store excess stormwater above ground and slowly release it into the council stormwater system. They can also provide water storage for reuse in your garden to save on water rates. So make sure your installer knows how you want to use it.

  • 1,000L stormPANEL – 1,950mm high x 1,520mm long x 460mm deep
  • 2,000L stormPANEL (COMING SOON) – 1,950mm high x 3,130 mm long x 460mm deep
  • Ultra-slim above-ground water tank.
  • When space is tight, stormPANEL tanks are ideal for existing and new homes.
  • Designed to not be seen
  • Easy to handle

Available from Devan or from WaterSmart or from the Tank Guy.

1000L to 5000L – stormBANK

1,000L stormBANK above ground slim line tank system is designed for easy expansion, up to 5 tanks, should your future needs change. The tanks are available in all 11 standard Devan colours.

A single tank:

  • Tank Width 870mm
  • Height 2,000mm

Available from Devan

5,500 L

  • Width: 1.9 metres Height: 2.3 metres
  • Outlet(s): 1 x 50mm (2 inch) brass BSPT fittings.
  • Bury up to 500mm deep with clean backfill.

Available from Devan

25,000L Promax

Just one example of the many larger tanks

  • Diameter: 3660 mm ~  Height: 2800mm ~ Weight: 387.6kg
  • Can be buried up to 1 metre in the ground and still retain a 20-year warranty
  • 10 weeks lead time (last time I looked)

Available from Turfrey

Other suppliers of above-ground tanks

Below ground or below deck options

These suppliers have above-ground tanks available, but also below-ground options or to go under a deck

  • Baileys Tanks ~ above ground, underground, under deck
  • New Water ~ the website doesn’t seem to work very well, but they seem to have a slimline under deck/floor product that could be good for small spaces, so might be worth giving them a ring ~ 0800 4 NEW WATER

Master list of tank suppliers

This link is from Wellington Water and shows all tank suppliers locally and nationwide. New suppliers may show up from time to time.

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