Estimation of Water Balance and Water Losses in Water Utilities – Experiences from the Belgrade Waterworks - page 5

 

Estimation of Water Balance and Water Losses in the Belgrade Waterworks

System description

The Public Utility Company "Belgrade Waterworks and Sewerage" (BWS) supplies over 1,350,000 residential customers, the majority of industrial and all municipal institutions in the Belgrade area. 60% of the total abstracted water originates from groundwater, while 40% is abstracted from surface waters - the river Sava. The distribution network has over 2,500 km of pipes, 20 pumping stations and 21 water tanks with an estimated 1,000 km of service connections. The distribution network of the Belgrade Waterworks is divided into five water supply elevation zones, which are arranged on elevations between 70.00 and 325.00 m.a.m.s.l. In recent years, annual water production has been slowly declining, totaling around 210 million m3 in 2007, while billed consumption was just over 150 million m3. The Infrastructure Leakage Index (ILI) for the entire water supply system was estimated at 6.5 (Cvjetkovic, 2008). However, no additional data on performance indicators in water supply zones or parts of the city are available, nor reliability or confidence limits of estimated data.

BWS production generally meets customer demands throughout the year, but occasional water shortages occur during summer months on the border areas of the BWS network due to transportation limitations of the distribution network and unauthorized water consumption. Low water rates, leaking water installations in buildings and poor water conservation practices have encouraged high water consumption per capita (over 200 l/cap.day).

Estimation of Water Losses and Performance Indicators in Belgrade Suburban Areas

Analysis of the water supply network and water losses in different suburban areas of Belgrade (i.e. "pilot zones") started in 2004. The main characteristics of the four investigated pilot zones are given in Table 2 and their location in Figure 3.

 

Table 2: Number of inhabitants and water meters in investigated pilot zones

Pilot zone

Inhabitants

Water meters

Kumodraž Selo

4,000 549

Jajinci

4,000

1,169

Baćevac

8,000

2,503

Velika Moštanica

5,300

1,524

 

Figure 3: Location of four investigated suburban areas – pilot zones