WinSLAMM Simulation of Hydrologic Performance of Permeable Pavements—A Case Study in the Semi-Arid Lower Rio Grande Valley of South Texas, United States

Abstract

This study used the Source Loading and Management Model for Windows (WinSLAMM) to develop a set of calibrated hydrologic models for three types of regional permeable pavements—porous concrete pavement (PCP), permeable interlocking concrete pavement (PICP), and interlocking block pavement with gravel (IBPG). The objective was to assess the hydrologic performance of permeable pavements, including the runoff depth, peak discharge, percentage increment in runoff reduction of pavements as a function of rainfall depth, development area, and base aggregate porosity, respectively. The permeable pavements were monitored over a wide range of rainfall events in the semi-arid Lower Rio Grande Valley of South Texas. Data regarding rainfall intensities, source characterizations, runoff coefficients, and pavement design were initialized as WinSLAMM input. Validation results showed that the calibrated models could over or under-predict runoff reduction within a 30% error range. PCP and IBPG were very effective and could be capable of handling storms as large as 50-year frequency over a 24-h time period. The modeling results showed that PCP might require a 50–60% lesser footprint area as compared to PICP and IBPG, respectively. Additionally, PCP might be able to store 30% additional runoff if the porosity of base aggregates was increased by 40%.

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

“…Additionally, climate change and changing rainfall patterns will influence the future performance of permeable pavement systems [39]. In southern semi-arid climatic regions, such as the LRGV in South Texas, summers are hot and humid with a daily average temperature above 32.2 • C for most of the year due to currents in the Gulf of Mexico [40]. Tropical storms in the coastal region of the LRGV are abundant during summer months.…”

Water Quality Improvement and Pollutant Removal by Two Regional Detention Facilities with Constructed Wetlands in South Texas

“…Before May 2012, the samplers were initially programmed to draw a fixed aliquot (100 mL) for every 41 m 3 of flow once the event started; this decision was based on a preliminary evaluation of historical rainfall data and drainage areas and estimated runoff coefficients. From the 2011-2012 data, a new sampling protocol was developed based on an event of 17,000 m 3 of design inlet flow to fill up a 3 L volume or one 100 mL aliquot for each 567 m 3 [40]. The percentage load reduction of pollutants achieved by the RDF for each monitored rainfall event was calculated using the following a mass balance equation:…”

“…The transformation of the watershed from its natural state has contributed to a water-quality problem. The watershed has been exposed to non-point source pollution from the extensive agricultural development that is interspersed with areas of rapid urban development [3]. Henceforth, an overload of nutrients and oxygen-demanding materials was transported across the river stream water; both components of this overload were associated with agricultural and stormwater runoff.…”

“…Inflow Volume,2 Outflow Volume,3 Concentration for E. coli = MPN (Most Probable Number)/100 mL,4 Standard Deviation,5 25 Percentile,6 75 Percentile,7 Removal Efficiency,8 Number of Samples, 9 N/A = Not available,10 Mean concentration.…”

Decision-Support System for LID Footprint Planning and Urban Runoff Mitigation in the Lower Rio Grande Valley of South Texas

“…Rapid urbanization and industrialization have significantly fueled the total percentage of impervious land cover (such as traditional parking lots driveways, sidewalks, roofs, etc.) within the major watersheds of the United States (US) [1][2][3][4]. Urban land developments increased by four times between the years 1945 and 2010 [5], which eventually altered the watershed hydrology and triggered an uncontrolled runoff towards major rivers in the US [6].…”