Reliability-Based Approach to Investigating Long-Term Clogging in Green Stormwater Infrastructure

Using rainfall measures to evaluate hydrologic performance of green infrastructure systems under climate change

“…Although adjusting bioretention basin characteristics altered performance (Jennings, 2016), poor performance was mostly attributed to areas with high rainfall totals and high-intensity events. Rainfall conditions have also been shown to influence clogging of green infrastructure and thus to affect required maintenance schedules (William et al, 2018).…”

“…Adaptation decisions could also be informed based on modeling future GSI performance using climate change scenarios; however, given the uncertainty and complexity of climate models, more straightforward techniques are needed. Since previous studies have linked GSI performance and maintenance to rainfall characteristics (e.g., Davis et al, 2012;Jennings, 2016;William et al, 2018), one such technique may be to use publicly available rainfall observations as a proxy for expected system performance. A better understanding of the critical features of rainfall patterns (i.e., intensity, frequency, and inter-storm timing) that affect current performance of GSI could inform how performance should be expected to change over time as rainfall changes.…”

Call for a Dynamic Approach to GSI Maintenance

“…Rather, municipalities should craft a comprehensive maintenance approach that complements their resources and goals, employing individual maintenance frameworks where they are most effective from a risk-based approach. Identifying risk factors and using them to prioritize maintenance activities allows a maintenance schedule to be customized for a particular GSI site according to its specific needs and as the needs shift over time (William et al 2018), which may provide cost-efficiency. A proactive maintenance framework can readily employ a risk-based decision-making process that would help focus limited resources where they are most essential or will have the greatest impact in achieving desired goals (Van Auken et al 2016).…”

Moving Toward Dynamic and Data-Driven GSI Maintenance

“…An MC simulation accepts ranges of values for each input so that the output is a probability density function describing possible outcomes. In GSI applications, MC simulations can inform risk-based decisions that incorporate uncertainty in contributing factors such as weather or soil characteristics (e.g., rain garden clogging and associated risk threshold; William et al 2019). One limitation is that MC simulations require defined relationships between factors and outcomes, which can be challenging if these dynamics are not well understood or vary over time (such as fall leaf drop).…”