Detailed Rain Garden Flow Monitoring

Rain gardens are infiltration best management practices that are installed in existing and new construction for the purposes of water quality in receiving waters and stormwater volume reduction. Nationally, rain gardens are transitioning from landscaping features with beneficial environmental effects to facultative engineered systems for meeting water quality standards or providing peak flow attenuation in combined sewersheds. The design, installation, and monitoring of the hydraulic characteristics of typical rain garden installations on private residential property are presented. Infiltration tests by infiltrometer and full-inundation methods were conducted, and ongoing inflow/outflow monitoring were measured with high-precision level meters. The performance of typical, residential raingardens and the flow reduction to combined sewer systems is estimated.