Living in a country like the United Kingdom, where there is a lot of rain, homeowners often have a need for a Rainwater soakaway. Many houses utilise the public sewers or public watercourse to drain away water during a rainstorm, the plastic guttering at roof level and downpipes are used to channel the excess water into the existing drainage systems. Some properties are remote from the public sewer system and need a way of disposing of surface Rainwater such that the ground nearby does not become a quagmire or turn to mud.
If the area being addressed is less than 100 m² then a Rainwater soakaway is probably the easiest solution. Simply speaking a soakaway is a pit which has been dug in the ground and filled with material such as rubble to preserve air gaps within the structure. This enables water to flow into these gaps and remain in the ground, under the surface, until it soaks away into the ground. There are more complex constructions for a Rainwater soakaway which can involve masonry walls or perforated ring units made out of concrete or even plastic as with a soakaway create. The main issue for a Rainwater soakaway is the gradual buildup of silt within the structure and the they need to be refreshed every 10 years or so as the water holding capacity is gradually reduced.
There are various regulations which govern rainwater soakaway design which have been developed to avoid impact on adjoining properties and to ensure that the soakaway has sufficient capacity to deal with a typical storm, for example a small soakaway is need to be able to cope with rainfall of 10 mm in a 5 min period.
There are also soakaway regulations which prohibit the development of a soakaway within 5 m of a building or public road as an example. They also restrict the development of a Rainwater soakaway in unsuitable ground which for example would be where the existing water table is above the level of the bottom of the proposed Rainwater soakaway. If there are any doubts over the capacity of the land at the property to absorb the estimated rainfall then a soakaway percolation test will need to be carried out.
The homeowner may sometimes see an adverse impact of a blocked soakaway. If you see water leaking out of the downpipe on your drainage system or overflowing from the top level gutter it could be that the water is not able to flow away quickly enough and that the Rainwater soakaway has become blocked. As mentioned before this could happen through silting up over it but also could because through infestation by tree roots or blockage caused by the accumulation of leaves in the winter. The former of these may require the construction of a new soakaway whereas the latter can be cured by the removal of the blockage.
If there is no obvious immediate cause of the blockage then it may be that you need to call him a drainage contractor to investigate and use a CCTV system to look within the drainage system before starting to excavate the rainwater soakaway as this can be an expensive and messy.