Monitoring of Pervious Pavement/Infiltration Bed System in Aurora, Colorado

This paper presents the monitoring results of infiltration-based stormwater best management practices (BMPs) for a commercial development site in Aurora, Colorado. Although the Denver Urban Drainage and Flood Control District (UDFCD) has criteria for pervious pavement and for infiltration-based BMPs, these practices have not been widely used in the Denver Metropolitan Area, and very little monitoring data have been collected to evaluate the effectiveness of such practices. The site evaluated by the study described in this paper is a 9.35-acre parking area for a commercial retailer. The parking area consists of sections of pervious asphalt and pervious concrete pavement underlain by gravel infiltration beds as well as areas of traditional pavement which drain to bioswales. The bioswales are connected to the infiltration beds beneath the pervious pavement sections. Through a series of perforated pipes, monitoring of the site began in the spring of 2006, and over a two-year period, fourteen events have been captured. Monitoring has been conducted using automatic stormwater sampling equipment for collection of water quality samples from the bioswales and using Barologger level measurement devices to evaluate infiltration bed hydrology. Nine groundwater monitoring wells were installed to evaluate the effects of the infiltration-based BMPs on groundwater. Water quality samples and level measurements collected from wells have yielded groundwater quantity and quality data that complement the monitoring data from the bioswales and infiltration beds. Results of groundwater monitoring will be discussed in a forthcoming, separate paper due to space constraints of conference proceedings. This paper focuses on surface water hydrology and quality. Monitoring is scheduled to continue for a third year, and additional monitoring in the future (10 to 15 years) could be extremely valuable for evaluating performance of the system over time.