Good Practices on Leakage Management - Austrian Case Study: Small Utilities
The EC Report ‘Resource and Economic Efficiency of Water Distribution Networks in the EU’ (October 2013) concluded that high leakage of around 50% would not be exceptional in small or medium size urban communities located in the mid or upper regions of catchments with readily available access to good quality mountain water resources gravitating to them from above where they incur minimum treatment and distribution costs. Alpine regions of Italy, Austria, Slovenia, Croatia, Romania, the Pyrenees and highlands of Scotland were mentioned as typical examples.
The actual situation identified during consulting and research activities in Austria was quite different from the EC Report (2013) conclusion. In adoption of the ILI and litres/connection/day as the most appropriate leakage KPIs in Austria (OVGW W 63 guideline, 2009), most Austrian utilities achieve very low levels of leakage (ILI close to or slightly less than 1,0), while individual very small Austrian utilities can achieve even lower leakage levels. This Case Study presents water loss assessment results for small Austrian urban and rural systems and briefly examines reasons as to why low leakage levels can occur in these communities.
1. Structure of Austrian Water Utilities
Statistics Austria (2014) categorizes Austria’s urban regions as follows:
- 6 urban regions with more than 100.000 inhabitants in the core zone.
- 9 medium-sized urban regions with 40.000 to 100.000 core zone inhabitants, and
- 18 small urban regions with fewer than 40.000 inhabitants in the core zone.
Out of the 2.354 Austrian municipalities 2.128 have less than 5.000 inhabitants. Because of this structure Austria has about 5.500 water utilities (OVGW 2014):
- About 1.900 municipal utilities.
- About 165 water associations.
- About 3.400 water cooperatives.
Approximately more than 5.000 of these utilities have less than 3.000 service connections and can be considered as ‘very small utilities’; around 4.500 of these utilities have less than 1.000 service connections. A significant number of utilities serve less than 100 service connections. These small structures are common in most parts of Austria, especially in the Alpine regions and also in other rural regions, which belong mainly to the Danube River Basin (Table 1).
2. Water Loss Situation of small Austrian Utilities
While a significant number of small utilities achieve low losses, there have of course also been single situations where losses have been high and no proper water loss management was implemented. Figure 2 shows ILI data from three different years (all less than 10.000 service connections). According to the Austrian banding system most of the utilities achieve low (ILI < 2) and medium (2 < ILI < 4) losses and a significant number of very small utilities achieves ILIs below 1. The reasons for these low ILIs are various and are discussed in the following sections of this Case Study.
Joerg Koelbl; firstname.lastname@example.org