Na osnovu potreba vršenja mjerenja protoka i pritiska u cilju sagledavanja raspoloživih količina vode, kao i stanja vodovodnog sistema sa filterskog postrojenja “Tilava” sa kojeg se snabdijeva veći dio opštine Istočno Sarajevo, izvršili smo u prvoj fazi početna terenska mjerenja protoka i pritisaka na unaprijed utvrđenim stalnim i privremenim-kontrolnim mjernim mjestima.
In order to fully understand the state of the network and the capacities available in the distribution of drinking water, in addition to measuring flow and pressure, which were used for analysis, from permanent measuring points, ie measuring DMA zones, measurements were performed with ultrasonic portable flow meters. as well as measurements with portable digital pressure gauges.
Pressure measurement on MMP1 was performed in the underground hydrant in the street of the First Sarajevo Brigade near "Adiko" bank in the time of 48 hours with a measurement interval of 1 min.
After the pressure logger was dismantled, the data was read and diagrams were made.
In order to improve the situation in the water supply of KP "Vodovod i kanalizacija" a.d. East Sarajevo and maintained the trend of continuous water supply without reductions, it is necessary to implement measures and interventions on the existing water supply and communal infrastructure, and above all to strengthen the detection and elimination of failures in order to save the amount of water currently available.
Based on the needs of measuring the flow and locating faults in the water supply system in Kreševo, the customer Hydro Control “d.o.o . Ilidža in the capacity of the Purchaser and NMAqua s.p Dejan Predojević in the capacity of the Contractor, performed field measurements and control of consumers and pipelines in the period from 11.03. to 13.03.2021. years.
According to the previously performed works on the water supply system JKP “Kostajnica” Kreševo and the Minutes from the field visit within the Project “Improvement of water supply in the municipality Kreševo” and the performed step test on the branch of the Meljine reservoir from by the client, it was necessary to perform micro-location of the area of losses on the specified part of the water supply network.
Flow measurement in subzones
It was also necessary to measure the flow and control the parts of the network where the illogical difference in the amount of flow at the measuring points is shown, for the part of the water supply network from the Meljine reservoir, which according to the previous step test suspected significant losses.
Measurement of quantities in the Meljine reservoir
Due to more expeditious work and research of illegal consumption and locations of uncontrolled consumption, ie losses, three flow meters were installed on the part of the main water supply network, which needed to be examined based on the results of the step test. Based on the results of measurements and analysis, parts of the water supply network were determined, on which it was necessary to perform detailed research.
By installing a flow meter in the Meljine reservoir, the amount of water entering the reservoir was measured, as well as the amount of water leaving the reservoir. Meters were placed before the water meter at the inlet and after the water meter at the outlet, where the most favorable conditions for measurement existed. After the measurement, a difference in the amount of water entering the tank between the water meter and the meter was observed.
After the first phase of flow measurement and research of losses and analysis of measurement results, and according to the Activity Plan, during May on the part of the water supply network supplied from the Meljine reservoir ultrasonic flow meters were installed at measuring points where there were even the smallest conditions for correct measurement.
The measuring points were determined in order to get the most complete insight into the distribution of the amount of water coming out of the Meljine reservoir on the part of the network where there are certain losses. During the measurement, three measuring points for all-day metering, seven places for control instantaneous metering and two metering points according to consumer business facilities were determined.
Simultaneously with the installation of the flow meter at the measuring points, the installation of the noise recorder was performed. The results of noise recording showed that the noise level does not indicate the existence of failures in the parts of the water supply network where they are installed.
After the completion of works on control, measurement and testing of pipelines and connections, it is estimated, based on the measured flow values, that about 4 l/s of uncontrolled water leakage on the water supply network was detected in the form of located faults.
According to the measurement data, considering the measured flow of the entrance to the Meljine reservoir of 8,145 l / s before detecting faults, night output of 6,606 l / s, the calculation gives a loss of about 80%, while reducing the night by 4 l / s faults on 2,606 l / s received a loss of about 32%.
Based on the conclusions on the conducted measurements and analysis of the results, Proposals for further activities to reduce losses and establish stability in the water supply system of the municipality of Kreševo were defined and presented. They need to be implemented as soon as possible in order to have a stable water supply of the population and economic capacities during the reduction of spring capacity, as well as increased consumption during the summer period.
