A Comparison of Three Types of Permeable Pavements for Urban Runoff Mitigation in the Semi-Arid South Texas, USA

This study examines the hydrologic and environmental performance of three types of permeable pavement designs: Porous Concrete Pavement (PCP), Permeable Interlocking Concrete (PICP), and Interlocking Block Pavement with Gravel (IBPG) in the semi-arid South Texas. Outflow rate, storage, Normalized Volume Reduction (NVR), Normalized Load Reductions (NLR) of Total Suspended Solids (TSS), and Biochemical Oxygen Demand (BOD5) were compared to results obtained from adjacent traditional pavements at different regional parking lots. A notable percentage of peak flow attenuation of approximately 31-100% was observed when permeable pavements were constructed and implemented. IBPG was capable to hold runoff from rainfall depths up to 136 mm prior to flooding. PCP was the most satisfactory in reducing surface runoff (NVR: 2.81 x 10(-3) +/- 0.67 x 10(-3) m(3)/m(2)/mm), which was significantly (p < 0.05) higher (98%) than the traditional pavement. PCP was also very effective in TSS removal (NLR: 244 x 10(-5) +/- 143 x 10(-5) kg/m(2)/mm), which was an increase of over 80% removal than traditional pavement. IBPG (NLR: 7.14 x 10(-5) +/- 7.19 x 10(-5) kg/m(2)/mm) showed a significantly (p < 0.05) higher (46%) BOD5 removal over traditional pavement. These results demonstrate that the type of permeable pavement and the underlying media can significantly influence the runoff reduction and infiltration in this climatic region.