The document presents a decision support framework for sustainable drainage design that quantifies the green values of drainage systems and compares design options. It aims to develop a standardized approach that considers multiple benefits, such as water quantity/quality, environmental impacts, and energy savings. The framework uses inputs like drainage design models to calculate key performance indicators, monetary costs/benefits, and compares green/sustainable designs to traditional gray approaches over the lifetime of the systems. The goal is to move beyond subjective opinions to evidence-based comparisons that maximize multiple benefits through optimization techniques.