In order to find the optimal solution for the drainage of rainwater from roads in urban areas, as well as for the evaluation and ranking of conceptual solutions, appropriate mathematical models and software packages were used in this research. For relevant rain episodes, i.e. rainfall of appropriate duration and intensity, runoff coefficients and flows were taken into account and analyzed according to the rational method, all for the purpose of obtaining data on the amount of rainwater entering the sewage system. Through this research, very good correlations and regressions were established between the cross slope of the road and the parameters of rainwater drainage from the road, as well as the correlation and regression relationships of the cross slope of the road and the efficiency of the drain. Likewise, the dependences of the drainage parameters, the efficiency of the drains and the cross slope of the road were determined, expressed through mathematical functions.

This paper presents an analysis of water flow and flow velocity in an open channel of rectangular cross section as a function of channel roughness, ie Manning roughness coefficient. Three different cases of finishing the open channel of rectangular cross-section were analyzed, namely the concrete channel, the channel with smoothed cement mortar and the channel in very poor condition with shore erosion overgrown with sedges and large stones at the bottom of the channel.

In Bosnia and Herzegovina, there is a large number of non-sanitary landfills and landfills where pharmaceutical waste from households is being disposed, as well as the medical waste from different health institutions. Expired pharmaceuticals are mostly being disposed there, because there is very little attention paid on waste sorting at the place of its origin. Now days, there are thousands of different medicine, and mainly, along with the other household waste, expired antibiotics are disposed of too. Degradation of expired pharmaceuticals in the environment very often leads to formation of products with completely different properties in regards to the original compound, but also it is not uncommon for those newly formed products to be more toxic than the original ones. This paper analyses the impact of rainwater infiltration on the body of the landfill where expired pharmaceuticals are being disposed of, as well as other medical waste at municipal landfills in Bosnia and Herzegovina. Field studies on the size of the rainwater infiltration as a function of different parameters have been conducted, and also degradation analysis of different expired drugs that are being disposed of in landfills has been performed.

Water consumption in a settlement is an extremely variable size that changes constantly over time. Changes in water consumption occur on an annual, monthly, weekly, daily and hourly basis, and depend on many factors such as: climate, season, temperatures, hours of work, consumer habits, etc.Extreme value of consumption, ie. the peak hour flow is defined as the product of the average daily consumption and the hourly non-uniformity coefficient. Non-uniformity coefficient is defined as the ratio of maximum flow to mean flow over a day, and given that actual flows fluctuate constantly over time, then it is easy to conclude that the non-uniformity coefficient is a variable that varies over time. In this case, the non-uniformity coefficient can be represented as a function C=f(t), which has local extremes at certain points, while at all other time intervals it has a smaller value.With the known function of uneven consumption, using computer technology, it is possible to program different simulations of consumption and flow in the water supply system. In this way it is possible to optimize the system itself in terms of water consumption, dimensions and capacities of facilities in the system, as well as energy consumption for water transport.

The major task of multi-purpose reservoir „Modrac“ operation is to decide how much water should bereleased now and how much should be retained for future use given some available and/or forecastedinformation at the beginning of the current time period. In practice, reservoir operators usually followrule curves, which stipulate the actions that should be taken conditioned on the current state of thesystem. Through construction of the dam Modrac in 1964, the reservoir of the same name was formed.Its primary objectives were the provision of technological water for industries in the Tuzla region andmitigation of downstream floods as well as recreation and other purposes. The multi-purpose reservoirModrac is currently a drinking water source for the municipality Tuzla. In order to better manage of themulti-purpose reservoir „Modrac“, certain analyzes are presented in this paper.This paper presents an analysis of annual precipitation, mean annual inflows in the catchment area ofthe multi-purpose reservoir „Modrac“ for the period 1967 - 2016. In this paper there are presentedstatistical datas on the maximum amount of precipitation for the dry season period (May to October) fordifferent return periods, for different distribution curves, as well as the maximum amount ofprecipitation for the wet season (November to April) for different return periods for different curvesdistribution.This paper provides information on the movement of precipitation changes in the catchment area ofmulti-purpose reservoir “Modrac” for the period from 1967. – 2016.

The water supply system is a set of facilities related to a functional unit with the primary aim of ensuring sufficient quantities of quality water by the most economical way. Design and implementation of such systems requires extensive previous research and analysis aimed at finding the optimal solution of water supply system. This paper presents an analysis of the pressure pipeline of the water supply system in which discussed several alternatives with different input parameters. It is shown the influence of the position and the number of tanks in the system on the basic parameters such as a pressure in the pipeline, power of pump units and so on. It's analyzed the impact of changes in diameter of the pipe to the hydraulic parameters, and also to the initial and operating costs of the system. The main aim of the complete analysis is to establish a uniform depending of the analyzed elements in the system and finding the optimal parameters and their relationship that provide the most appropriate solution from the technical and economic aspects.

Modrac hydroaccumulation is the largest and most important multi-purpose water resource for water supply to large industrial capacities of importance for Bosnia and Herzegovina, but also for public water supply of Tuzla and Lukavac. Since the water quality of the hydroaccumulation is threatened by the waste water of a large number of different pollutants in the basin area of 1.189 km², and that the useful volume of hydroaccumulation is limited, then during the time it comes to the filling of the hydroaccumulation dominated by coal dust from coal mines in the basin reservoirs. It must be ensured that good quality water is supplied to consumers, especially households and industries, while ensuring hydrobiological minimum dilution of waste water discharged into the river Spreca downstream from dam and reservoir Lukavac.

Dam Modrac is multiple arched reinforced concrete buttress dam, with nine buttresses and ten arches, which by its technical characteristics and volume of the accumulation is considered as one of the high dams. Crown level of spillway is 200.00 m a.s.l. Crest length is 205.00 m, while the maximum height is 27.50 m. To control the water level in the reservoir, under normal hydrological conditions, there are four basic discharges with maximum capacity around Q = 77 m3/s for the projected state. The paper gives an analytical expression of the spillway curve and analytical expressions of amounts of water discharge separately for each bottom outlet, which are obtained by conducted measurings. Special significance of this paper gives volume curves for hydro accumulation Lake Modrac for projected state and the period of use of the system.

The dam and hydro accumulation Modrac are located in the northeastern part of Bosnia and Herzegovina. Construction of the dam was completed in 1965, and that year the accumulation was filled. Hydro accumulation consists of three rivers Spreča, Oskova and Turija. In recent years, the useful capacity of hydro accumulation was significantly reduced compared to the originally projected state. The main cause of reduction in the useful capacity is increasing quantities of the silt, mainly coal dust from the coalmine Banovići. Today, hydro accumulation lake is mainly used for water supply of Tuzla power plant and the supply of drinking water the towns of Tuzla and Lukavac. Keywords— Dam, Hydro Accumulation, Silt, Water Capacity.