All of the pavements assessed displayed crossfalls and longitudinal grades that are considered to be typical of PICP (0.5 % to 2.0%). Typically, permeable pavements will not build-up sediment loads in a uniform manner for various reasons and most likely it will tend to exhibit zones where sedi-ment build-up is more concentrated. For this reason a testing regime was devised ensure that infil-tration tests would be conducted in both high and low sediment load areas. Where possible each pavement was tested at the lowest and highest elevations and, in some cases, at intermediate posi-tions. Tests were also conducted below or adjacent to trees so that the effects of leaf litter could be evaluated.
In general, the paving was tested “as found” without any attempt to clean the surface prior to infil-tration measurements. However, in three locations, tests were also conducted after the surface had been vigorously swept with a stiff broom. In all cases, before measurements commenced, the sur-face was flooded with water. Repeated measurements were made at each test location to ensure that the tests were conducted under saturated conditions.
The lowest infiltration rates recorded from the repeated testing at each site are summarised in Table 2. From this table it may be seen that, for the pavements laid using pavers provided with drainage openings along the joints (Ecoloc and EcoTrihex), the measured infiltration rates ranged from 27 to 1080 mm/h/m2 (75 to 3000 l/s/ha). The lowest values were recorded at Olympic Park, Sydney. Subsequent investigation established that all of the low infiltration rates resulted from tests that had been inadvertently conducted over sewers, water mains or other buried services. It is possible that, in these locations at Olympic Park, the service trenches had not been backfilled with permeable ma-terials.