Well we have mostly filled it to the top of the rainwater tank.
Blog
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Earth Tube Collection chamber
Where the earth tubes get close to the house we have built a block work chamber to concentrate the air flow down too a smaller tunnel to pass under the foundations of the house. The chamber is 300mm below the path round the house.
Concrete ready for the blocks 
The view down a tube – we vacuumed the sand out 
Test fit of the blocks 
Finished chamber -
Progress over the last week
Filling in the hole is not the most exciting thing to write about so here is a summary of our progress. The weather has not been as good as recent weeks, which has slowed our progress a bit.
Carefully filled and compacted on south side of the tank and behind the earth tubes. Installed the rainwater input pipe.
We decided that the area outside of the garage footprint could be filled in bulk and allowed to settle if necessary, so fill was dumped in from an edge and the next load beyond it. There was some compaction by the weight of the dumper truck driving over the fill.
Then we measured and laid concrete around the earth tubes nearest the house, this will support a block work chamber which gathers the air into a smaller area to feed into the house by a tunnel. As I said the rain has been a bit more frequent in then last week, indeed we had just mixed a load of concrete when torrential rain fell. Guess where the lowest point was for the rain to collect …. yeah the formwork ready for the concrete! Luckily the rain stopped long enough for the area to drain away and we managed to place the concrete half an hour later.
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Rainwater Overflow pipes
Installed the final section of pipe in the great hole. This is the overflow from both the filter module and the tank to the soak away.
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The Grand Fill of the Great Hole – Part 1 (so far!)
The various modules, pipes, tubes and tanks are now installed in our Great Hole. It is the long job of putting back all the sand and soil into the Great Hole, making sure each layer is compacted well (we are doing about 200mm (8 inches) at a time). After all the garage has to sit on top of this area so we do not want gradual sinking of our foundations or floor slabs in five years time!!
The only pipework left to do is the connection for the soak away module running back towards the black tubes, on the way a over flow from the rain tank connected to it and finally turning the corner to head left back towards the filteration unit module (not built yet!).
Wednesday 8th September (yesterday) we returned the Kanga Kid earth mover machine. It was costing money every day so on Tuesday we decided to do a large filling operation in the further and least accessible corner of the Great Hole where it would be awkward and very hard work to do it by manual labour, as it would be too dangerous to drive the much too heavy dumper truck over the rain tank without the support of any sand on it to spread the load!! We didn’t finish until nearly 7pm!!
Today we are carrying on with Operation Fill Up which will take another few days or so! Phew!!
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Rainwater Tank Day 4
Placed the last layer of crates …
Time for Christmas Eve! Well we have a lot of wrapping to do…. Wrapped, folded and trimed the polyfelt first. Next the rubber was folded up the sides and the extra rubber in the corners folded neatly.
We formed a couple of pipe connections for expansion at the bottom right and overflow at the top left. These were sealed by cutting a half-sized hole in the rubber and stretching it over the pipe. This formed a ring of rubber about 2cm along the pipe which was covered in a stip of geo-textile and clamped with a stainless steel tie. The overflow level is 40mm from the top of the tank.
Finally we wrapped up the outer geo-textile and added more geo-textile as a lid. The access shaft was installed last.
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Rainwater Tank Day 3
Spent the morning laying the 3 layers of material down. 1st layer was standard geo-textile (grey), 2nd layer was the waterproofing EPDM rubber membrane (Black) and last was Polyfelt padding (White). The rubber was the hardest to get in position as it is one piece (of course!) and quite heavy in total.
Once the wrappings were done laying the crates was straight forward and by the end of the day 2 of the 3 layers were placed.
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Rainwater Tank Day 2
Did preparation work for installing the rainwater tank. Started by marking out and leveling the sand for the base of the tank, we spent so time getting the right as we don’t want the tank to be off level!
Then we humped the 87 aquacell modules down into the hole from their delivered location next to the house.
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Rainwater Tank Day 1
Had a relaxed day today. Went and purchased some mini access chamber raising rings and a lid to use on the rainwater tank for access into it.
Then made a hole in the top of a aquacell module for a raising ring, attached it and removed the bottom of the module to make a hole right through. Made the same size hole right thorugh another module for the middle layer of the tank, then made a hole in just the top of a final module for the bottom of the access shaft. We will place a submersible pump here.
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Rainwater Soakaway
Installed the rainwater soakaway this afternoon. We carefully leveled the area in the corner of the trench and then placed geo-textile down. Then installed 18 Aquacell modules in a 3m x 3m array, the modules were clipped together. A hole was made in to top to allow connection from the rainwater system. Finally the geo-texile was wrapped around all 6 sides.
