Potential of Pervious and Macro- Pervious Pavements as Harvesting Systems for Irrigation of Adjacent Lawns and Flower Beds

Pervious pavements have been used as water harvesting systems and the value of water derived from pervious pavements as irrigation water studies have shown for landscaping. An alternative system is a modification known as a macro-pervious pavement system (MPPS). These devices infiltrate water through discrete points into a porous subbase offering all the benefits of the pervious pavement system (PPS) along with an ability to use the specially designed infiltration systems as a means of protecting the sub-surface environment from
major oil spillages. After a consideration of the essential similarities and differences between the PPS and MPPS, this paper reports the latest results from an ongoing study aimed at assessing the suitability of water derived from both pervious and macro-pervious pavement installations for irrigation use. In particular, it highlights the complications caused by the application of de-icing salts in winter. The latest results are reported from on-going field studies of a 7-year old MPPS and, for comparative purposes, an 11-year old PPS. It also considers the quality of the effluent if, disposed of to a water course and, in the case of the MPPS site, considers changes in water quality since the previous study in 2011/12 and the initial data from a recently instigated pot trial which uses water derived from such parking surfaces to irrigate turf grasses. The chemical analysis results to date indicate that except for problems associated with road salt addition during winter the effluent constitutes an excellent source of irrigation water.