Efficiency of Flood Control Measures in a Sewer System Located in the Mediterranean Basin

Abstract

Pollution induced by surface runoff in urban areas constitutes a significant problem. The adoption of control measures aimed at improving the quality of recipient water bodies is a fundamental issue in the management of Mediterranean Basin sewer systems. Previous research in Mediterranean areas using small virtual basins has shown that rainfall regimes have a limited impact on the pollutant load and discharge flowing into a receiving body. The aim of our research was to identify a sizing methodology for stormwater tanks located in the Mediterranean Basin. To achieve this, a numerical model of a sewer system, located in the Southern Iberian Peninsula, was developed. Different patterns related to peak periods of rainfall were considered. Furthermore, efficiency indices were used to evaluate and compare the effects of having a stormwater tank in the system. In our study (which considered a real area), significantly varied values were obtained for the pollution load removal rate (η) and the receiver overflow rate (θ). We nevertheless observed that, in our catchment, at a specific volume of V = 60 m3/ha, η and θ reached constant values without experiencing any significant improvement (η = 0.673 and θ = 0.133). Based on our model, this volume was proposed for the stormwater tank. The ATV (German Association for Water Pollution Control) A 128 standard was applied in order to validate the results, and the specific volume obtained (V = 60 m3/ha) matched with the one proposed. Thus, our proposed methodology is simple and different, and it is very easy to apply by obtaining the values of the efficiency indices η and θ through the development of a Storm Water Management Model (SWMM).

Urbanization and Management of the Catchment Retention in the Aspect of Operation of Storm Overflow: A Probabilistic Approach

“…of the catchment imperviousness, and thus the balanced development of the catchment area, has a significant impact on the reduction of the annual number of overflow discharges, which has an impact on the improvement of the quality of the receiver waters and the state of ecological equilibrium. This fact is confirmed by the works of numerous researchers conducting field studies and performing computer simulations [1,[55][56][57]. In the catchment in question, the reduction of the degree of land imperviousness in the successive years by 2-10% leads to a decrease in the annual number of overflow discharges from Za = 2 to 8 (Figure 7).…”

Decision Criteria for the Development of Stormwater Management Systems in Poland

“…Implementation of the developed decision support model in the investment process will enable an unbiased comparison of a conventional stormwater management system with alternative solutions that include rainwater harvesting [76,77], underground and surface infiltration of stormwater into the soil [78,79] and its retention [80][81][82]. Due to the significant number of available devices ( Figure 5) and their possible combinations, both with each other and with stormwater pre-treatment facilities, the decision process must only take into account the options that are technically justified under the given circumstances.…”

StreamflowVL: A Virtual Fieldwork Laboratory that Supports Traditional Hydraulics Engineering Learning

“…Similarly, the rise in the occurrence of higher runoff increases the load of pollutants and the overflowing of sewers. Furthermore, higher flooding frequency carries a greater possibility of waterborne disease outbreaks, following the overflow of treated and untreated wastewater sewer systems; at the same time, flooding causes serious damage to properties, agricultural and economic activities, as well as human losses [52,53]. In addition, population growth, urbanisation, and significant leakages in pipe networks are enforcing rapid changes in some areas, leading to a dramatic increase in high-quality water consumption.…”