Integrated urban water modelling using Aquacycle model

The traditional approach to urban water management is primarily based on a supply-oriented
approach, where water follows a one-way path from supply to a single use, treatment and
then discharged to the environment. The wide acknowledgement of the need to shift towards
more sustainable practices has led to the recognition that demand is multi-faceted; delivered
supply should correspond to the varying characteristics of users, taking into account their
actual needs in terms of quantity, quality and level of reliability. Such an approach can entail
the application of reuse and reclamation methods, which allow for the multiple use of water to
meet higher to lower quality needs.
Integrated urban water cycle modelling can be a powerful tool in estimating the potential for
the application of such options, as it considers issues related to water supply, wastewater
production and stormwater runoff in a holistic framework. This paper presents preliminary
results from the application of an integrated urban water balance model, Aquacycle, in the
Greater Athens Area. The Aquacycle model accounts for water pathways by simulating two
subsystems of the urban water cycle (the rainfall-run-off network and the water supplywastewater
network), and the interactions between them. The software package can also be
used for evaluating alternative stormwater and wastewater reuse schemes.
In this paper, Aquacycle was used for simulating water use, wastewater production and
stormwater drainage in the Greater Athens Area. For applying the model, the region was
divided into smaller – cluster – scales, according to specific structural characteristics. Then,
the model was calibrated and validated against measured data, so that model outputs can
account for the overall complexity of the Athens urban environment. Finally, three alternative
scenarios, comprising the application of on-site recycling and reuse technologies were
simulated and evaluated on the basis of three sustainability indicators (i.e. reduction of
imported freshwater, wastewater and stormwater discharge).