Modelling water quality for urban flood storage reservoirs

• Published in: Environment international Vol. 21; no. 2; pp. 177 - 186
• Main Authors: Ellis, J.B., Hall, M.J., Packman, J.C.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier Ltd 1995; Elsevier
• Subjects: Applied sciences; Drainage; Exact sciences and technology; Floods; Freshwater; Hydraulics; Mathematical models; Natural water pollution; Pollution; Q1; Rainwaters, run off water and others; Urban planning; Water pollution control; Water treatment and pollution; Water tank; Water quality; Water pollution; Urban area; Flood(streams); Modeling; Sedimentation; Drainage water; Storage tank
• ISSN: 0160-4120; 1873-6750
• DOI: 10.1016/0160-4120(95)00007-0

The paper outlines a simple modelling basis for estimating the pollutant removal efficiency for flood storage reservoirs receiving drainage water from impervious urban surfaces. The procedure is based on particle-size characteristics, settling velocities of the suspended solids contained in the influent drainage, and consideration of hydraulic retention time within the storage basin. Worked examples illustrate the modelling principles and include details for obtaining overall trap efficiency under both quiescent and dynamic flow for given particle sizes, basin geometry, and inflow conditions. A hydraulic routing algorithm extends the basic procedure to determine mass pollutant outflows from the flood storage basin under varied flow conditions as defined by a typical inflow storm hydrograph. Full details of the algorithm are provided together with a worked example to illustrate the trap efficiency of a storage basin having a controlled outflow and subject to a typical 2-y design storm event.