Geotechnical Assessment of Soil Permeability in Land Development Areas

Infiltration is identified as one of the best operational and sustainable methods to handle urban storm water. Until recently, in stormwater management designs and selection of best stormwater management strategies, permeability value of different soils were not been considered as major factor. Due to the increasing housing density local land development authorities requires storm water runoff from developing lots to be retained/detained within the property. Due to lack of information on local soil properties, specifically permeability rates within the soil predominant in land development areas, it is difficult to assess storm water retention/detention requirement. This case study was carried out within the new development areas in Gosnells in Western Australia mainly focusing on identification of different soil types with respect to their infiltration capacities in selection of best stormwater management strategies. The Guelph Permeameter have been used to investigate the saturated permeability of different soil types. Based on the above tests, the results have been categorized in to four main types of permeability groups; Very Rapid (> 1.56 m/day), Rapid (0.48<1.56 m/day), Moderate (0.12<0.48 m/day) and Slow (