Review and optimization of the operation of potable water supply sources: case of the Metropolitan Area of Monterrey

Abstract

A simulation-optimization model was developed in R to simulate the hydrological cycle of the dams that are the main sources of surface water. This was complemented by forecast information of climatological variables and the demand of the Metropolitan Area of Monterrey (MAM). The model simulated scenarios that were based on the extraction infrastructure and sustainable operation of the sources, using the Particle Swarm Optimization algorithm to minimize an objective function that aimed to lower the extraction operation costs and ensure continuous water supply. To simulate precipitation and runoff from the contribution basins, historical data on the dam regime of the studied vessels and the demand for the last ten years of the AMM were used. These data were provided by the operating agency Servicios de Agua y Drenaje de Monterrey (SADM), while climatological data were collected from open information by the National Water Commission (CONAGUA). Databases were created using stochastic models such as seasonal autoregressive integrated mobile media (SARIMA) and neural autoregressive networks (NNAR). These databases contain monthly historical information on the dam regime (direct precipitation, evaporation, and extractions), monthly precipitation of the selected climatological stations, and the water demand of the MAM. Based on the simulation results, it was concluded that maintaining the water consumption trend of the last 10 years is not feasible. The demand exceeds the annual concessions identified, and all sources remain under high operational stress. However, the scenario of increased extraction capacity for one of the surface sources is ideal for maintaining continuous supply, respecting current annual water allocations, and the sustainability of the aquifers. All scenarios indicate that unless better and incremental extraction infrastructure is developed, demand will not be met unless aquifers are overexploited beyond their natural recharge.