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Home › Forums › SUSTAINABLE CONSTRUCTION, ENERGY and WATER CONSERVATION › Building and Construction › New in ground water tanks
We have two 10,000 litre water tanks being delivered tomorrow, about a month before the roof they will be catching water from is finished.
It’s a bit late, but we’re worrying that the tanks might pop out of the ground if there’s rain before the tanks are plumbed in. The supplier was here on Friday to check the hole and the access. He was very definite about the backfilling, but didn’t say anything about risks of leaving them empty during wet weather.
I’ve googled around a bit without finding anything specific. Does anyone here know if there’s a risk of damage to the tanks, or what’s the minimum level to prevent it?
Tanks… I mean Thanks :blush:.
Simple physics dictate that equal water in the tank to what body of water it is in to prevent it from ‘popping’ out.
But if your tank holes are made correctly and back filled with gravel as with the base of the hole, you should have adequate drainage.
From what I understand with underground tanks, if there is a concern with drainage, they usually install an outflow pipe at the base of the hole to allow water to run out instead of pooling.
How was your hole constructed?
The base of the hole is a levelled 2-tank sized rectangle covered with gravel dust which has also been levelled – obsessively – twice. The bobcat left a pile of dust which I presume he intends to use as the lowest layer of fill. I don’t see any provision for an outflow pipe. OTOH the hole is cut into a pretty steep hill.
When you think about it this must be a fairly common situation – new tanks and new building to fill them. We’ll check again with the supplier, but we’re probably worrying unnecessarily. Hope so.
You’re right, this is a common situation.
The common practice, in my experience, is to have a water tanker pump enough water into the tanks to prevent them from floating due to a heavy rain event.
The cost of a water delivery (or two) as opposed to the cost of having the base material reconstructed and the tanks repositioned if they float, seems an easy decision.