With the hot sun and strong breezes rapidly drying the soil after the
winter rains it was possible to assess more accurately the problem the
diggers had encountered when trying to construct the drive up the plot
from the house.
At first it was thought that the sheer volume of
water overflowing from the storage tank and moving down the site was
causing the diggers to sink up to their axles into the drive at the
point where this flow and the drive intersected. However, by ensuring
the overflow was directed away across the site and the drying weather it
became apparent that there was, as I had long suspected, a slower and
deeper spring outlet following the same line down the plot.
Whilst
the rainfall last winter was exceptionally high I decided that a small
catchment tank with an overflow directed away from the drive would be a
sensible precaution.
The digger that was on site therefore dug
out a hole which was then lined with a couple of the standard cess pit
concrete rings which were themselves lined with polythene to form a
tank with a gap being left on one side to allow the water to enter the
tank.
It was then capped off with the standard capping and an
over flow made so that any excess of water would join the around the
house drainage system and be used to water an area lower down the plot.
Given
the design of the house, earth sheltered on all but the south facing
window wall, the only practical option for the drainage, and sewer runs
was along the front of the house. The digger, therefore, dug a suitable
trench and the necessary pipework was installed with access points at
all joins in order to facilitate easy resolution of any problems.
Some
of the rocks previously put on one side for walling purposes were built
into a rocky retaining wall to support the soil at the side of the
drive adjacent to the newly installed water run off tank and to provide a
natural way for the excess water to make its way into this mini holding
tank before seeping away or being run off, via the overflow, down the
site.
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| Starting to dig the hole for the catchment tank. |
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| Unloading the concrete rings. |
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| Moving the first ring into place. |
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| First ring in place. |
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| After adding second ring polythene was used to line the tank leaving the up slope facing side exposed to allow the water to seep through and collect in the tank and then it was topped off with a concrete lid. |
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| Digging the trench for the sewer and waste water runs. |
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| Laying the waste water run to carry the around house drainage water and the overflow from the newly installed catchment tank. |
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| Laying the sewer run. |
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| Building a retaining wall at the side of the drive, using rocks previously dug out of the excavation, to support the soil and provide an easy run off into the newly installed tank. |
