ABSTRACT
This paper discusses the influence of the direction and velocity of precipitation wave on the required retention capacity of the innovative Retention Sewage Canal solution. Simulations were performed in a real municipal catchment equipped with a storm water drainage network, with the use of SWMM 5.1 hydrodynamic software. The formulated research task was realized after determining boundary conditions at efflux of storm water effluents from the drained catchment, assuming that the maximum intensity of effluent efflux from the Retention Sewage Canal is 600 dm3/s. Results of simulation tests allow to determine that both the direction, as well as velocity of movement of precipitation wave have a small impact on the determined, required retention capacity of the Retention Sewage Canal in the analyzed design variant. It was also determined that the highest required retention capacity of the object is always caused by precipitation moving from the west to the east at 3,0 m/s velocity. However, from the performed tests it may be concluded that the taking of precipitation movement over the assumed municipal catchment into account does not cause any changes in the value of calculational precipitation duration for dimensioning the Retention Sewage Canal, which in the created design concept assumes a value of 100 minutes. Comparing the results of model tests, determined for stationary precipitation and precipitation moving over the catchment, it was demonstrated that the differences in the required capacity of Retention Sewage Canal are inversely proportional to the duration of precipitation. For this reason, when adopting higher values of sewage flow reduction coefficient β in the Retention Sewage Canal, the determined differences in its required retention capacity would be higher than if dynamic rainfall for adopted for analysis.
