Paper 5643 - Role of Maintenance in the Performance of Stormwater Control Measures

Abstract:

Stormwater Control Measures are required by jurisdictions across the USA and internationally to treat runoff quantity and quality. Like any anthropogenic device, these systems must be maintained. However, often times once a system has been constructed, it is neglected, either assumed it will work in perpetuity or (more likely) just forgotten. Recent research on multiple stormwater practices illustrates the pitfalls of neglecting certain practices, while highlighting other SCMs that are resilient despite lack of care. The focus of this presentation will be to highlight three often-used SCMs, constructed stormwater wetlands, bioretention, and permeable pavement, describing each SCM's failure modes. The degree to which water quality and hydrologic mitigation function is lost will be presented for each practice. Moreover, design and construction guidance will be provided so that the exposure to failure mechanisms is limited for each practice. Of the three practices, it appears that their resilience to failure is (in descending order): constructed stormwater wetlands, bioretention, and permeable pavement. One key to the former two practices robustness seems to be the important role in vegetation, which helps heal "wounds" of neglect. Because constructed stormwater wetlands do not rely upon filtration, they tend to be slighly less prone to failure than bioretention (which is a filtration-based SCM).