Long Term Simulation for Efficiency of Sedimentation Tanks

Abstract

For dry stormwater sedimentation tanks (without permanent water level) the relationship between efficiency, specific tank volume, maximum inflow and surface flow rate was investigated. The study was based on continuous long term simulation of 50 configurations of stormwater tanks and 40 rainfall locations in Germany. The total efficiency is mainly i nfluenced by the specific tank volume, the surface flow rate and significantly the local rainfall conditions. The study recommends to design dry sedimentation tanks for specific tank volumes of 5 ≤ VRKB,spez ≤ 20 m³/ha and a design surface flow rate of 5 ≤ qA,b ≤ 10 m/h. Long term simulations are advised to study the influence of local rainfall conditions on the efficiencies of sedimentation tanks.