Stormwater White Papers

Stormwater science encompasses the study and management of water from rainfall and melting snow that runs off impervious surfaces such as roads, rooftops, and pavements. As development increases and natural land cover is replaced by built environments, the volume, timing, and quality of stormwater runoff changes, often leading to flooding, erosion, pollution of waterways, and degradation of aquatic habitats. To address these issues, stormwater science draws on a wide variety of resources—hydrologic and hydraulic models, monitoring programs, best management practices (BMPs), regulatory manuals, and case studies—to understand how water moves through landscapes, how it can be retained or treated, and how human and natural systems interact. 

Each paper in this section is crafted to illuminate how stormwater treatment technologies work, why they matter, and how they can be applied in the field. 

Basics of Gravity Separation Devices

Gravity separation is one of the most widely deployed pollutant removal mechanisms in stormwater treatment systems. It is one of the primary unit processes used in various stormwater control measures (SCMs) such as wet or dry sedimentation basins, baffle boxes, and hydrodynamic separators. Flow-through SCMs that rely on gravity separation can be used in stand-alone treatment applications, or as pretreatment to other SCMs depending on local stormwater regulations and treatment goals. This Basics of Gravity Separation Devices series of technical papers will guide the reader through the fundamentals of gravity separation SCMs.