The occupation of urban areas impacts urban water balance. Waterproofing of the urban soil causes run-off to increase, generating more frequent flooding in cities. In order to reduce the impact caused by occupation, compensatory strategies based on soil infiltration techniques are now often proposed in the design of building systems. This paper compares two on-lot infiltration systems: a rain garden and a dry-well. Infiltration systems were installed in an experimental area and the investigation involved monitoring these parameters using level sensors and high precision water meters. Water inflow, infiltrated volume and overflow were analysed in simulated rain events. The results indicate the importance of considering the infiltration portion in the dimensioning of the infiltration systems. Furthermore, a better performance of the rain garden was observed in decreasing the peak flow rate, and higher efficiency of the run-off volume when considering the drywell.
On-lot drainage; Drywell; Rain garden
