SLAMM, the Source Loading and Management Model

TLDR: The Source Loading and Management Model (SLAMM) as mentioned in this paper was originally developed to better understand the relationship between sources of urban runoff pollutants and runoff quality, with minimal reliance on pure theoretical processes that have not been adequately documented or confirmed in the field.

Abstract: The Source Loading and Management Model (SLAMM) was originally developed to better understand the relationships between sources of urban runoff pollutants and runoff quality. It has been continually expanded since the late 1970s and now includes a wide variety of source area and outfall control practices (infiltration practices, wet detention ponds, porous pavement, street cleaning, catchbasin cleaning, and grass swales). SLAMM is strongly based on actual field observations, with minimal reliance on pure theoretical processes that have not been adequately documented or confirmed in the field. SLAMM is mostly used as a planning tool, to better understand sources of urban runoff pollutants and their control. Special emphasis has been placed on small storm hydrology and particulate washoff in SLAMM, common areas of misuse in many stormwater quality models. Many currently available urban runoff models have their roots in drainage design where the emphasis is on very large and rare rains. In contrast, stormwater quality problems are mostly associated with common and relatively small rains. The assumptions and simplifications that are legitimately used with drainage design models are not appropriate for water quality models. SLAMM therefore incorporates unique process descriptions to predict more accurately the sources of runoff pollutants and flows for the storms of most interest in stormwater quality analyses. However, SLAMM can be effectively used in conjunction with drainage design models to incorporate the mutual benefits of water quality controls on drainage design. SLAMM has been used in many areas of North America and has been shown to predict stormwater flows and pollutant characteristics accurately for a broad range of rains, development characteristics, and control practices. As with all stormwater models, SLAMM needs to be accurately calibrated and then tested (verified) as part of any local stormwater management effort. 4