Regardless, for the discerning patio or driveway customer, for the more clued-up contractor, and for the innovative garden designer, the Natural Paving 2017 brochure will provide much to consider, and even more to inspire. Forget the whys and wherefores that seem to have dominated this review,...
Note that this is the storage volume required between the dry base or water table level of the soakaway, and the invert (inlet) level of the incoming drainage pipe, and assumes that the chamber is empty, not filled with old bricks, lumps of concrete or gravel, etc., as is often found...