Aspect is examining the effectiveness of 10 bioretention facilities across the Puget Sound and North Sound through the combined analysis of continuous flow and rainfall data, vegetation, geotechnical, and modeling. Aspect designed and installed custom hydrologic monitoring stations to work with the unique inflow and outflow designs of each facility. We are maintaining the monitoring stations and managing and analyzing level, flow, groundwater, and rainfall data over a ten-month study period. Aspect will perform the analysis of the hydrologic mass balance data set and work with the project team to write the final report once data collection is complete. The results of this study will be submitted to the Regional Stormwater Monitoring Program/Stormwater Action Monitoring and will inform NPDES permittees in the specification and design of bioretention facilities that perform well and meet the requirements of the stormwater manual and their permits.