Hydrologic Performance of a Permeable Pavement and Stormwater Harvesting Treatment Train Stormwater Control Measure

Water quality performance of a permeable pavement and stormwater harvesting treatment train stormwater control measure

“…Assuming a 40% porosity in the AASHTO #4 aggregate of the IWS zone, a completely empty IWS zone would only capture (without drainage) the 11.4-mm event. During inter-event periods, the IWS zone quickly dewatered such that exfiltration occurred only from the scarified soil (5 cm thick) underling the aggregate (Winston et al 2020). The dewatering of the IWS zone was caused by a leak in the cistern which allowed stormwater to move from the IWS zone through the backfilled soil and into the cistern, preventing drainage from occurring in 52 of 59 storm events, which is quite dissimilar to other studies of permeable pavements constructed over clayey soils (Fassman & Blackbourn 2010;Winston et al 2018).…”

“…Runoff reduction in the treatment train stormwater control measure represented 27% of the overall water balance during the monitoring period (Winston et al 2020). This was primarily due to exfiltration from scarified subgrade soil beneath the permeable pavement with minor contribution from leaks in the cistern causing it to partially dewater during inter-event periods.…”

“…Measurement of run-on to the permeable pavement was not possible since diffuse inflow occurred along its upslope end ( Figure 1). Runoff entering the permeable pavement from the 100% impervious catchment was determined for each qualifying rainfall event using a rainfall-runoff model, the NRCS curve number method (Winston et al 2020). To determine the drainage and overflow rates, standard equations for 30°and 60°v-notch weirs, respectively, were used to determine flow rate from measured flow depth.…”

“…A permeable interlocking concrete pavement (PICP) retrofit underlain by a cistern made up of two interconnected concrete vaults was constructed in June through July 2014 at the Old Woman Creek National Estuarine Research Reserve visitor center parking lot located in Huron, Ohio (Figure 1). The SCM was constructed on poorly draining hydrologic soil group (HSG) D soils (Del Ray silty clay soil; Soil Survey Staff 2015), with average infiltration rates of 0.046 mm/hr measured in soil pits located within the permeable pavement extent (Winston et al 2020).…”

It Is Not Easy Being Green: Recognizing Unintended Consequences of Green Stormwater Infrastructure

“…Novotny et al [198] found that, in the Twin Cities Metropolitan Area of Minnesota (USA), 72% of chloride from winter road salt application remained in the watershed, presumably being retained in soil and groundwater, with concentrations as high as 2000 mg/L found in shallow groundwater wells. High chloride concentrations can also cause the release of metals that are fixed to soil particles [199]. Once released, the metals are free to move with the water into the groundwater.…”