Risks and Potentials Related to Shallow Urban Aquifers

Unconfined urban aquifers as source and sink are a key element within the total urban water cycle. Unlike deeper and mostly better quality aquifers, shallow urban aquifers are (i) much more vulnerable to contamination from urban landuse, (ii) may impact urban infrastructure more directly by cellar flooding and infiltration into sewers, (iii) are easily accessible and therefore abstraction is harder to control. For the latter, they are often used - but rarely managed. In the present study, the Mexican city of San Luis Potosi (1.1 Mio inhab.) is used to demonstrate an assessment framework for shallow groundwater resources in integrated urban water management (IUWM). Assessment parameters include aquifer geometry, flow regime, water quality, existing use and potential water demand. The evaluation shows that the shallow aquifer is fit for different type of use concepts. The results have been communicated to the local stakeholders and are expected to actively influence planning and regulation processes.