Von Netzalter, Wasserverlusten und Schadensraten zur langfristigen Erneuerungsplanung

Though planning/defining a long-term rehabilitation strategy for drinking-water supply facilities is a frequently discussed topic, it also represents a daunting challenge. Various factors have to be taken into account, e.g. the longevity of drinking-water distribution network – which is determined by e.g. the choice of material, pipe diameter and underground conditions – on the one hand; and by operational constraints – e.g. the need to coordinate planned measures with other service providers and/or the road works, which can result in pipe sections being replaced sooner than planned – on the other.

In order to achieve sensible and sustainable rehabilitation planning, the current status of the facilities and distribution network must be carefully assessed. In this regard, aspects such as water loss and failure rates could be used as a basis for status appraisals.

Furthermore, the municipal structure (e.g. urban or rural) significantly impacts the strain on facilities (e.g. through excavations, increased traffic, etc.), and accordingly, on their actual service lifespans. The specific distribution network structure also significantly impacts the cost of rehabilitation.

The paper shows how the assessment of infrastructure current status can be used for better rehabilitation planning. On the basis of the latest insights gleaned from the ÖVGW benchmarking regarding network age, water loss and failure rates, it shows which influencing factors should be kept in mind. Finally, the example of a prioritization plan for rehabilitation strategy clearly demonstrates that the importance of a specific system component is also relevant for session making.