Sustainability assessment of low-impact development methods for urban stormwater management: A multi-criteria decision-making approach

Low-impact development (LID) methods are used in urban areas as sustainable stormwater management solutions. However, previous studies often lack situational scenario-based assessments and cover a limited range of criteria and indices, overlooking key factors, especially in developing countries facing significant sustainability challenges. This study addresses these gaps by assessing the sustainability of four LID alternatives, including novel combinations of rain barrels (RBs), rain gardens (RGs), permeable pavements (PPs), infiltration trenches (ITs), and vegetative swales (VSs), for inside and outside the house in a case study located in Tehran, Iran. In addition, 22 quantitative/qualitative indices were selected across environmental, social, economic, and technical criteria. The three-phase indices evaluation involved 1) simulating the study area by the stormwater management model (SWMM), 2) collecting quantitative data, and 3) scoring qualitative indices through questionnaires. A modified analytical hierarchy process model was employed to rank LID alternatives in difficult, poor, transition, satisfied, and ideal scenarios. Considering situational scenarios, the results showed that IT and VS for outside the house consistently performed best, adding novel contributions. Sensitivity analysis confirmed the robustness of this finding despite changing criteria weights. This study provides a new framework for urban decision-makers in developing countries to adopt resilient stormwater solutions.