Adaptation of sewer networks using integrated rehabilitation management.

The urban water structure is aging and in need of rehabilitation. Further, the need to address future challenges (climate change, urban development) also arise lines. This study investigates if it is possible to combine rehabilitation and adaptation measures. To do so, we combined an urban development model, an urban drainage model and a rehabilitation model. A case study of a medium-sized alpine city with a sewer length of 228 km and a population of 125,431 was used to develop and apply this method. A priority model to pinpoint the structures in need of replacement was used. This model considered a deterioration model, vulnerability estimation and other influences. Further different rehabilitation rates and methods were examined. The urban development model used is a simplistic approach specifically tailored for the field of urban infrastructure management. Climate change is considered in terms of climate change factors. All these different influences together create scenarios for which the construction costs and the flooding volume are estimated and compared. Consequently the aim of this paper was to test to which degree it is possible to reduce urban flooding by adapting those parts of the network which require rehabilitation anyway. In our case study it could be reduced by 5%.