Underground Rainwater Storage in an IBC With Pumped Supply





Introduction: Underground Rainwater Storage in an IBC With Pumped Supply

Budget pumped rainwater storage. Commercial rainwater storage can be several thousand pounds. To save money I wondered if you could bury an IBC and it turns out you can ! Here's a complete pumped rain water system for about GBP 100.

See more inside......

Step 1: Dig a Big Hole

Dig a very big hole. A standard IBC can be bought for GBP 40-50 and is 1mx1mx1.2m. It took about 3 evenings after work to dig the hole. We're lucky and have nice light soil.

Step 2: Put Your IBC in the Hole and Connect

Drop that beast in there. I put a bottle gully at the base of the downpipe. I used a holesaw to cut a 100mm hole in the side of the IBC for the water in. For the overflow I used 40mm pipe which I drilled lots of holes in a ran it to a soakaway.

Step 3: Make It Nice Again.

I first backfilled with earth. Next I used weldmesh to cover the IBC and fitted a inspection cover (From Drain Center) over the screw cap on the top. Then I poured with concrete.

Not too bad looking, if I say so myself.

Step 4: Connect the Pump

Found an excellent pump on ebay for GBP 50 from a German seller called "werkzeuge-online"
It's a cheap Chinese knock off but works fine. It's got an accumlator and a pressor switch which holds the water at 2 bar.

Mounted in the garage. Ran the suction hose through the wall into the IBC. Ran 15mm pipe to the garden tap, which now runs pure rainwater !

I've been using the system for Aug and Sept and it's been perfect. The tank has been nearly full the whole time.



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    Please be positive and constructive.




    Caving in does NOT sound good! Especially if you're intending to use that water in your house on a daily basis. But it's a good idea to make the most of the rain and save a bit of your water bill. Perhaps we could work out a way to pack the storage container a little bit better or put in some reinforcements on the walls of the hole in the ground to ensure it doesn't fall in on itself anymore!

    Do the tanks cave in from the top or the sides? I'm thinking putting a sheet of fiberglass or thin sheet metal around the outside of the tank frame would keep the dirt from pushing in the plastic.

    Mine has caved after I had it in the ground empty for about 2 months. With a hole only 3 inch bigger than the tank on each side was enough to destroy my project. I was thinking to fill with water then cap it, fill with to concrete around and the frame to be as rebar. BUT theoretically would work but looking farther into it soon or later will cave in when its empty. JUST NOT MADE TO BE BURIED. Thank you but mine did not work if the tank runs empty or the level drops in the tank.


    Hello, i just read the post, and i am glad i did. We live in hollywood hills, in Los Angeles, and we have a major problem with drought and climate change. We are lucky to have a natural spring beneath our property the spills out fresh water in a corner of the our front yard at a rate of 750 liters per day. So i am trying do design a system that captures that water, stores it underground, pressurize it up to 100 psi , and connect it to the main the sprinkler system. What you did is very close to what i am intending to do. I just do not know what type of tank and pump is right for the job.

    Looks great, a few questions for you: Did you site the feed to your pump slightly above the bottom of tank (so as to avoid sediment in the bottom)? Did you put any filters in your set up (I suppose your trap under the downpipe removes a lot though)? If your pump is above the tank, does it have a priming function? And....is it still working well?! Thanks!

    Looks great. I have read a lot about these caving in if the tank runs empty. Also that they can crush if the ground water fills up and the tank is empty. Have you had any issues like this?

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    So the IBC was £50 and the pump was £50, where do I get free mesh, free concrete, free shelving brackets, free holesaw, free wall-deep masonry bits, free plumbing supplies etc.? Wickes, UK: Couple of sacks of concrete will be about £7. Bottle gulley £16 (areco.co.uk). Manhole cover £15. Shelving bracket and uprights £6. Holesaws £10. That's £54 more already. I'm guessing £200 at least. Also the cheapest IBC I found online was £200. werkzeuge-online (ebay shop, note spelling) does have a "garden water pump" like yours but for £40 (inc del.) but this one doesn't have the tank part, just the pump. So I'm looking at £340. I think a couple of rain barrels, fenceposts, few bits of pipe work and some gravity will do for me ... YMMV

    2 replies

    I bought my IBCs for much less - about 25-30, got three and delivery I think for under 100 quid (1000ltr ones)

    Have a look on ebay Ebay UK > Search IBC > Buy It Now Only Returns about 70 of the beasts between 18 and 50 quid. Thanks for the comments.

    Can you tell us more about the pump? Is it set up to avoid burning out if the tank runs dry?

    Thanks for the easy-to-follow explanation ed_sturdy! It's great to know it can be done without investing ££££s and involving consultants etc One question: any lessons learned now that you've had the system in place for a few months? Perhaps 2 IBCs rather than one (given our UK rainfall), or a different kind of pump? I'm curious to know because we've got an IBC and (due to tiny garden) we're thinking of doing pretty much exactly what you've done.

    Pay attention!!! Be warned.... a friend of me build a same solution, but here in the south part of the Netherlands the groundwater level is about 70 cm below the surface. Before it started raining the bottom of his still empty IBC was teared in pieces by the groundwater pressure. So that was the preliminary end of his project ;-( (By the way he had the IBC for free) Grtz Jan

    Nice Idea. One thing I have to ask is this... You stated "Ran 15mm pipe to the garden tap, which now runs pure rainwater !" Did the pipe your using now have mains piped water going to it before or was this an addition that you made?

    4 replies

    Garden tap was previously on mains. I capped the old pipework and ran new pipework from the pump. It's a auto pump which is nice as it's turns on with a pressure drop when you open the tap.

    If that is the case, you should check that your water company is not now over charging you for the now non-existent extra supply that was in your garden / garage.

    I think you only get metered to charge the costs.

    No you do not only get metered for water charges. You are also charged for run off from your garden and house in to the drains, sewage waste is also charged for and if your metered, they use the amount of your consumption to calculate sewage and grey water from the supply. Water company's also charge you if you have an outside water supply, a supply in your garage, shed, green house or wherever you put a water outlet on your property. If you really want to reduce your overall water charges, stop the garden and house run off from going down the drains, build a soak-away and have all excess from your ware containment flow in to that soak-away. I can not comment on if you need permission to build a soak-away but I do remember that when I was at home while my mother had an extension to the house built, the builder had a soak-away on the plans and before he could back fill it, the building inspector had to inspect it to ensure it had been built to spec. So it may pay to ask if planning permission is needed. This may not be as bad as you think because you would have to lodge plans of the build and that would be public record and the water company can not argue with that. So check!

    Before you dig such a big hole its probably a good idea to have your underground utilities located and marked.