Performance of low-impact development best management practices: a critical review

Abstract

Low-impact development (LID), a land planning and engineering design approach for managing urban stormwater runoff, has been widely adopted across the globe. LID best management practices (BMPs) are man-made features that rely on natural processes to manage stormwater water quantity and quality. In this article, recent literature (published after the year 2008) related to nine BMPs was reviewed to highlight the ranges in treatment efficiencies for 21 of the most frequently investigated runoff parameters. The primary function, pros and cons, and factors affecting performance of each BMP were discussed. A frequency analysis of the reviewed parameters showed that total suspended solids, total phosphorous, total nitrogen, runoff reduction, and zinc concentrations were the most frequently investigated stormwater runoff parameters. Five recurring themes were observed with regards to knowledge gaps and conflicting objectives for research related to LID BMPs that include: (i) lack of consensus on which parameters to measure for effective LID adoption, (ii) BMP performance is highly variable, (iii) many BMPs are known exporters of nutrient pollutants, (iv) lack of cold weather performance-specific studies for individual BMPs, and (v) lack of human pathogen-related stormwater quality studies for individual BMPs. Suggestions for future research are discussed to address these knowledge gaps.