
A subsurface structure into which surface water is conveyed to allow
infiltration into the ground.
Found on
http://www.encyclo.co.uk/local/20453

Where there is no main drainage, rainwater from a roof can be channelled into a hole filled with coarse gravel, from which the water can gradually soak into the surrounding soil. This is known as a Soakaway.
Found on
http://www.encyclo.co.uk/local/20938

An arrangement for draining rainwater into the ground. Usually a large hole dug and filled with broken bricks, rubble or similar 'waste' materials into which the rainwater is piped. Its effectiveness largely depends upon the type of soil surrounding the hole.
Found on
https://www.diydata.com/general_building/building_glossary.php

A method of water disposal (usually surface water) that disperses water from drains leading to it, provided surrounding soil conditions are suitable. A soakaway may consist for example, of a hole dug in ground and then filled with brick, rubble or similar material, and covered over.
Found on
https://www.encyclo.co.uk/local/20694
No exact match found.