Water Tanks Advice on what sizes would be most appreciated.

Hi there, I would truly appreciate advice here regading water tank sizes.

We have 2 dwellings on hectare. 3 bedroom main dwelling - 2 children, 2 adults (family)

and a 1 bedroom unit with a garage, 1 adult.

There is no business that requires water operating on the property. Only normal daily use activities.

May I ask what recommendations of what size tanks would be adequate for each dwelling?

We currently have 2 x 25,000 litre tanks, 1 each, about to be fitted in 2 weeks.

My question I guess is, is this size tank, each, adequate? Or .......

Thanks so much in advance.

Go as big as you can What you catch depends on roof area
Make sure you have low useage shower roses

Bigger the better in rural areas-think fire, drought.
A third tank that can serve both buildings would allow for cleaning one at a time without water supply problems.

Also, check your council regulations. From memory, we can have 25,000 without issue but over that and you have to have a permit of some sort. sorry a bit vague on this now as a long time ago we put ours in. Maybe something to do with fire, or maybe something to do with council wanting a fee if you store extra water they think is "theirs".
Also good to have reserve water if you keep a garden at all.

Auckland Council has announced it is scrapping resource consent fees for the installation of rainwater tanks at residential properties so I guess other districts will soon do the same.
According to the Devan calculator and assuming a roof area of 300 sq metres, you are on the edge of your storage with a 25k tank. If you are able to "borrow" from the other dwelling you may be ok. For the small extra money I would go 30k litres for each tank.

Whatever u do make sure that all tanks have isolation valves so u can individually isolate for servicing cleaning etc
Also have them self balancing

I would certainly be buying more if you are relying on roof water only to supply your needs. People are already running out Nth Waikato area and we are about 400mm behind in rainfall so far.

It costs between $250 - $275 in these parts for between 10,000 - 14,000 litres of water to be delivered. Neither of which goes very far if you have a family.

We have 50,000 litres for the house spread over two tanks and last year we had to buy in water. There are only two of us! Then we have a 5000gal farm tank and a 3000gal auxiliary tank and both those were empty. Stock will drink a lot of water.

Check out your annual rainfall (Google) then use a rain water collection calculator (online - eg Devans) wtih your roof area to figure out how much you can collect. We get about 880mm per year and have 330 sq roof area and now have 170,000 litre storage. All full as we go into summer. We run animals and an acre of flowers and veg. If we ha no stock and just the two of us then 2 tanks of 25,000 would be adequate

Installing large water tanks or raised water tanks may require Building Consent. The national criteria are given here:
www.building.govt.nz/projects-and-consen...ms/11-1-tanks-pools/

If you are building, you may need to comply with the requirements for fire-fighting water supply:
fireandemergency.nz/assets/Documents/Bus...code-of-practice.pdf
This affects positioning of the water source, required volume, pipe diameter, connection type (contact your local fire & emergency for advice), hardstanding & access for firefighting vehicle. Having a sprinklered house reduces the required volume.

Auckland Council has announced it is scrapping resource consent fees for the installation of rainwater tanks at residential properties. Storage tanks and pools don't require a building consent if they meet requirements for capacity and height-above-ground.

eelcat wrote: Check out your annual rainfall (Google) then use a rain water collection calculator (online - eg Devans) wtih your roof area to figure out how much you can collect. We get about 880mm per year and have 330 sq roof area and now have 170,000 litre storage. All full as we go into summer. We run animals and an acre of flowers and veg. If we ha no stock and just the two of us then 2 tanks of 25,000 would be adequate

Eelcat, for you, if you are running your flowers and vegetables as a commercial enterprise, you may come under your local water distribution system as holding water you need to pay for, so be cautious.
Our neighbour put in a bore and if it had been just for stock on his property, it would have cost nothing beyond the installation costs of the bore, but....because he runs growing houses and needs the water for that, he is metered and has to pay Watercare services as if he was on town reticulation.
I'm not clear on whether ground water use comes under a different "rule" to rain water catchment however.