The Albuquerque Metropolitan Arroyo Flood Control Authority and the City of Albuquerque recently completed a retrofit of the Lower Bear Tributary, replacing a deteriorating channel with a five-stage stormwater treatment train. Each sequential segment, referred to as a "car," provides a distinct level of water quality treatment as stormwater moves downstream. Cars 1 and 2 capture large and floatable debris through debris-capture fences designed for efficiency and maintainability. Cars 3 and 4 integrate green infrastructure, using vegetation and infiltration to remove pollutants and attenuate flows. Car 5 features a deepened channel that creates a ponding area for small to moderate storm events, increasing residence time and enhancing infiltration before flows continue toward the Bear Canyon groundwater recharge area and the Rio Grande. An auto-sampler installed at Car 5 supports event-based monitoring of flow and pollutant concentrations for performance evaluation and adaptive management. The presentation covers planning, design, construction, post-construction operations and preliminary monitoring results.