The goal is to reconstruct past system behavior and diagnose the causes of a major water crisis. In order to do this, we develop a hydrologic-engineering-economic model to address the complexity of urban water supply arising from consumers’ dependence on multiple interconnected sources of water.
We integrate different components of the urban water system: water flows into the reservoir system, diversion and distribution by the public water utility, groundwater flow in the aquifer beneath the city, supply, demand and prices in the informal tanker-truck-based water market, and consumer behavior. Both the economic and physical impacts of consumers’ dependence on multiple sources of water are quantified. The model is calibrated over the period 2002-2006 using a range of hydrologic and socio-economic data.
The model’s results highlight the inadequacy of the reservoir system and the buffering role played by the urban aquifer and consumers’ coping investments during multi-year droughts.