This article presents the steps made for the development of a new water
management system (WMS) for a private water utility in the south of Portugal, and its main
results. The WMS is composed of a set of models representing the water resources, surface
and groundwater, water quality models, economic models, and water allocation
optimization models. The system was developed at the request of the regional water utility
(Águas do Algarve, S.A.), which is responsible for distributing water to the entire Algarve
region (most touristic area in Portugal, with about ten million tourists per year, and a local
population of about four hundred thousand). Results clearly show that independently of the
amount of water available, inter-annual exploration is always the best solution, if possible.
When water scarcity is high, as in consecutive dry years, the water utility will need to call
municipalities to use their systems to complement supply. The level of supply deficit is
higher, in any case, for annual exploration management, and so are exploration costs. These
results clearly show that water resources management needs careful inter-annual planning,
even for a private water supply utility with very limited control over water exploration by
other competing users
