Dimensioning of Required Volumes of Interconnected Detention Tanks Taking into Account the Direction and Speed of Rain Movement

Mariusz Starzec,Daniel Słyś,Józef Dziopak,Kamil Pochwat,Sabina Kordana

doi:10.3390/w10121826

Abstract

This article is aimed at defining the impact of the direction and velocity of waves of rainfall as they pass over interconnected stormwater detention tank systems. The simulations were conducted for a real urban catchment area as part of the Storm Water Management Model (SWMM) 5.1 programme. The results permit us to conclude that the direction and velocity of a moving wave of rainfall have a significant influence on the required volumes of interconnected stormwater detention tank systems. By comparing the modelling test results for stationary rainfall and rainfall moving over the urban catchment area, it has been demonstrated that differences in the required volume of the detention tank located at the terminal section of a stormwater drainage system are inversely proportional to the adopted value of the diameter of the outfall channel for upstream storage reservoirs. In extreme cases, the differences may be up to several dozen percentage points. Furthermore, it has been proven that the arrangement of the stormwater detention tanks in relation to one another and the adopted diameter of the outfall channel are key factors in identifying the degree to which the detention tanks are hydraulically dependent on one another.

Highlights

In recent years, we have observed an increased frequency of extreme weather events, notably cloudbursts and long-term intensive rainfalls
The simulations were based on a hydrodynamic model of the real urban catchment area, which is located in Poland (Figure 1), using the Storm Water Management Model (SWMM) 5.1 programme
Stormwater drained from the initial sub-catchments will reach the terminal stormwater drainage cross-section before the rainfalls over the sub-catchments are assigned to the terminal sections

Summary

Introduction

We have observed an increased frequency of extreme weather events, notably cloudbursts and long-term intensive rainfalls. Their occurrence results in the hydraulic overload of stormwater drainage system and the devices integrated within it. Sewage systems are among the most expensive and the most difficult to implement, especially when operating in a gravity system [4,5]. The most capital-intensive type of sewage system is the stormwater drainage system. In order to improve their operation, for many years, they have been equipped with various types of detention tanks [6,7]. It should be remembered that the choice of the appropriate project option should be supported by the analysis of many indicators [8,9], including in particular a technical and financial analysis [10,11,12], as well as an environmental analysis [13,14,15], taking into account the lifespan of the investment [16]

Objectives

Methods

Results

Conclusion