Author(s): J. Marsalek; B. G. Krishnappan
Linked Author(s): Jiri Marsalek
Keywords: Urban stormwater; Stormwater management ponds; Suspended sediment; Settlingcohesive sediment; Flocculation
Abstract: Settling of suspended sediment in stormwater ponds is a relatively complex process, which is greatly simplified in engineering design. While the simplified approach seems to work in some facilities (favourable hydraulics, coarser, non-cohesive sediment), in other cases these simplifications may be inappropriate. Theoretical approaches (detailed flow distribution, focculant settling) are under development, but not yet advanced enough to be applied in practical design. The current empirical approach should benefit from detailed analysis of pond hydraulics (i.e., flow distribution, formation of dead zones and recirculation zones), allowances for inefficient storage utilization, and good characterization of suspended sediment by settling tests. Further improvements will follow from the ongoing research addressing physical properties of sediment flocs and their dynamic evolution in the pond, deposition and erosion functions, and the modelling of flocculation and transport of cohesive sediment in the pond.
Year: 2003