Subsoil drainage design — Perth residential and road developments

Extensive areas of the Perth Urban area are underlain by sandy soils, high water table and shallow depths to low permeability horizons. Drainage design involves considerations of subsoil drains, soak wells, stormwater sumps (for local authority drainage) and open ‘swale’ drains. This paper discusses approaches undertaken by the authors to the design of such drainage fixtures and provides some practical design guidelines for residential developments.