This research analyzes the peaks-over-threshold (POT) method for designed flood estimation needed to plan river levees, spillways and water facilities. In this study, a one-parameter exponential probability distribution has been modified by including the coefficient of λ, which represents an average number of floods and enables return period calculation within the specified period of time. The study also compares results using the Log-Pearson Type III distribution of maximum annual flows and a standard exponential distribution of the selected peaks over the threshold level. The aforementioned approach represents the standard mathematical tools for river flood design, while the proposed modification of the exponential distribution highlights the estimation of flood quantiles with longer return periods (e.g., 100, 1000 and 10,000 years). Moreover, the sensitivity analysis of the threshold selection is proposed to assist in the flood design flow estimation alongside the proposed modification of the exponential probability distribution. The study was carried out at the Danube River, and the Novi Sad hydrological station (Republic of Serbia) was used for the long-term recorded period from 1876 to 2015. The results suggest that the POT method derives more reliable estimates of design floods than the traditional statistical tools for flood estimation. The results suggest the theoretical values of the water level of the 10,000 years return period is equal to 867 cm, while the Log-Pearson Type III distribution of annual maximum flows underestimated this value for 14 cm.

This study investigated the interaction of groundwater flow and foundation piles located in the vicinity of the Danube River. The piles represent an obstacle to the groundwater flow, causing a backwater effect upstream whilst increasing the local flow velocity. On the other hand, a high flow velocity around the piles can cause suffusion of the surrounding soil in the long term, thus significantly reducing the shaft resistance of the piles. A 3D model of groundwater flow and its impact on the piles was developed in the software 10.3 package GMS based on MODFLOW 2005. The model was calibrated by comparing the calculated results with the measured values in the control well for different values of the filtration coefficients. In the calibration process, foundation piles were not applied in the model. After the calibration process, the piles were implemented into the model and the underground flow was simulated in the study area for the calibrated year 2006. The impact analysis was carried out by comparing the groundwater level change over time in the pile zone at three control points, in cases with and without the piles, along with the flow net analysis at the piles’ location. The results indicate no influence of the piles on the groundwater flow in the study area, both in terms of critical flow velocities and a possible backwater effect upstream.

Comprehensive hydraulic modelling of a large urban water supply system, based on GIS data, with actual spatial distribution of water demand achieved through georeferenced water metre data. Establishing a model for simulating a large urban water distribution system poses challenges from multiple perspectives. This paper presents an approach to modelling a complex network, demonstrated on the case of the regional distribution system of the city of Novi Sad. In the analysed study, an accurate model was developed using a comprehensive dataset encompassing all system components. A realistic spatial redistribution of demand within the network was achieved by including the complete set of water meters. This approach yielded straightforward calibration and high agreement between simulated and observed pressure and discharge values. The selected software package, EPANET-GISpipe, proved suitable for addressing such issues. The research has shown that a detailed analysis based on water meter readings enables reliable simulation of large-scale water distribution systems with complex operational dynamics.

The water supply system of the City of Novi Sad consists of facilities and a distribution network that supplies water to the consumption area of the City of Novi Sad and the Municipality of Sremski Karlovci. The water supply system supplies water to about 400,000 inhabitants, and the average annual production of water is about 35 million m3. The total length of the water supply network of the City of Novi Sad and Sremski Karlovci is about 1,200 km, of which about 200 km is an illegal water supply network. In the last decade, water losses in the water supply network have increased from 25% to around 32%, i.e. by around 0.7% per year. Water losses can be slowed down by comprehensive reconstruction of the water supply network and an active role in the fight against losses.

The Knićanin–Čenta subcatchment area, located in Central Banat, is a fertile agricultural region whose water regime is significantly influenced by the water levels of the surrounding rivers—the Danube, Tisa, Begej, as well as the Karaš canal. During May and June 2019, while the TurkStream gas pipeline was under construction, the area experienced heavy rainfall, resulting in flooding of approximately 35% of the total surface area of the Knićanin–Čenta system. The aim of this study was to determine whether, and to what extent, the construction of the gas pipeline—primarily the formation of barriers and the placement of pipes in the canals—affected the occurrence or extent of flood-related damage. For this purpose, a hydraulic model was developed using the EPA SWMM software package.