Underground Water Tank in front yard

We have just finished installing a concrete 7000L tank in our front yard and would recommend it as an alternative to bulky aboveground tanks on std size residential blocks. (subject to soil conditions etc.)
At about 7.5k installed it's probably a bit more expensive than above ground but with the price of land it evens out.
Anyone interested in a brief desciption and photos of the installation visit our blog below.

Can I ask why you chose concrete over poly?

Concrete will support itself and works just fine
onc_artisan

I have seen this done on a place near mine just recently. Can you landscape over it or does there need to be an access panel?

I'll be putting a slimline on the blind side of the hosue but would have liked a tank twice the size if space permitted. An underground one similar to yours below the paved courtyard would have been perfect if I thought of it early enough!

Yep, just needs a hatch
I just saw one yesterday... the guys have a 15000L tank.
onc_artisan

We've buried it to a level to allow 100mm topsoil over the 600 square gatic cover (obviously I will know were to find it if need be). There is actually 450mm cover over the tank lid which adds to the weight, allows the storm water pipe to come in at the top of the tank and gives good cover to the power and float sensor cables.
Poly underground tanks are generally in the form of a 'donut' or cylinder (laid flat) and ribbed to achieve the strength required and therefore expensive. Plastic has to be weighted down with tonnes of mass concrete. A concrete tank by default comes with weight built in.
The main limiting factor would be soil conditions. I would think the cost of hammering out rock as exists in most of Melbourne's western suburbs would make u/g unviable.

The council I live in has huge water storage requirements. I think my underground tank is 10,000 litres. I also have a slimline 5,000 litre above-ground tank. My underground tank is concrete, above-ground colorbond. I had to have a riser added to the lid of the undergound tank because the idiots that installed it did so way below the level of the surrounding ground. I may still have to bury the lid even with the riser.

Judie

we have a 300mm riser also. You could posibly add another riser.
That must have been a huge hole!

Two weeks and the 7000 litre tank is now brimming full.
Water tanks v desalination plant. (don't get me started)

Are you in VIC, mudmap?
That's a really good price for underground watertank.
I have asked around for my future watertank, which will be min. 9000 litres, will be $15-16K. If it's above ground (colorbond) is $10K.

Yes Victoria
If you looking for concrete in Victoria I would recommend Frankston Concrete Products. They provided the tank, rainsaver and pump (and advise). I organised the plumber and excavator. I believe they could posible arrange that also (at a cost).

Thanks, mudmap, but I'm in NSW. Everything's here seems more money.

Yay! Thanks for that info. Think i will be giving them a call too.

I'm very impressed. Great job. Will you be using the water for all outlets in the house, or toilet and laundry only?

We've plumbed to the 2 downstairs toilets and washing machine. I reckon they are the 2 largest users and ofcourse don't require treated water. I also plan to tee in 2 garden taps (1 front and 1 back). Maybe the car will get a wash and return it to it original colour.
Our daily usage over the last few years has been consistantly under 400 litres per day. With the new house we are installing efficent appliances and going to a front loader w/machine so with a 7000 litre tank there will still be times when it will be empty.

That is great. We have a 2500 litre tank that we use for nothing. It is on the other side of the house to the toilet/laudry, but I am keen to investigate whether we can still have it plumbed in. It would mean we wouldn't use scheme water in those areas during winter.

Dont think concrete in ground tanks can't float, they can. Just because they are made from concrete doesnt mean they are not prone to floating issues of polymer tanks. IF you live in an area where you have a high water level in the ground such as sandy areas, the tank when empty can pop out of the ground. I have seen heaps.
Biggest advantage of in ground tanks beside that you cant see it, is that you can capture the entire roof area. Make sure you invest in a reasonable in ground rainwater filter that provides good quality water going into your tank. Otherwise in 3-5 years from now, you will have to pay someone to clean out your tank and remove all the sludge.

Regards
Shane

I just got a price yesterday on a 21,000 Ltr in ground, formed on site concrete tank.
$8000.00 + G.S.T
Fair deal I say. They also priced a 10,000 Ltr tank, precast, dropped in, $4000.00.

I think, maybe the bigger one is the way to go, 5M X 5M hole will be needed.

That sounds like a good price.
Other considerations are a submersable pump and rainsaver switch (option).
The pumps usually have a limited distance to their control unit (10m in my case) so if your looking at 2.5m down the tank and 0.5m off the ground you need to consider it's location along with the distance between the hole and any structure.
I laid a couple hundred m2 of turf just before our heat wave (Vic) so used half my 7000 liters in one week. Managed to ration the rest untill the rain came but it goes quick.
The good news is that one day of rain fulled it to overflowing.

Wow!

4 of us had a 20,000 liter tank in Selby and we never emptied it. Though top loading washing machines and toilet flushing for #1 was strictly banned. Showers were 5 minutes by default - 20 liter hot water tank.

There was another rusty tank for the garden at 8000 liters, never used it.

I wasn't exactly frugal either. I managed to get 10 min showers using a trickle. I also used hand washing basin for clothes and the top loader to spin them out and a rinse sometimes.
If it rained I washed the car. I dug pits in the clay for watering fruit trees.

All of that water was supplied by a double car port roof. The house roof tanks had bullet holes in them. (2 x 40,000lt)
No one we knew The house came that way - renting.

I would say the roof was around 20 meters ^2 and a good rain of 3 hours would have the tank overflowing - down to the tanks with bullet holes.

I really miss those hills but you can have your barking dogs and chain saws..
The sound of thunder in the valleys was awesome - and puff..!