Green infrastructure is reshaping how communities manage stormwater by blending natural processes with modern engineering to improve water quality, reduce flooding, and fit into increasingly dense urban spaces. In this episode, Christian Hennessy of Oldcastle Infrastructure breaks down what makes a system truly “green,” from mimicking pre-development hydrology to using engineered soils, media amendments, and carefully selected plants to target pollutants like nutrients and metals.He covers how green infrastructure has evolved from simple rain gardens into high-performance, small-footprint systems that combine green and gray infrastructure through precast structures, filtration media, and controlled detention. Hennessy also explains how performance is measured through rigorous field testing and lab validation, ensuring these systems deliver real water quality results. Looking ahead, he discusses hybrid approaches, digital monitoring, and climate-driven design as essential tools for making stormwater infrastructure more resilient and effective in a changing world.Learn more about Oldcastle Infrastructure water solutions.waterloop is a nonprofit news outlet exploring solutions for water sustainability.