The Metropolitan City of Milan lies in the middle of the Po Valley, enclosed by the Ticino and the Adda rivers on its western and eastern sides respectively, and by the southern Alps on the north. Its whole region is characterized by the presence of smaller rivers, streams, and canals, which used to dominate also in the city center’s landscape up until 100 years ago (cerchia of navigli). Today, the canals of the city center are mostly buried underground to give space to motorized mobility, but water abundance is still typical of the urban area. Indeed, Milan lies on top of on of the largest Italian aquifers, which expands throughout the Po Valley and which made large scale agriculture and intense industrial development possible in this region.
The citizens of Milan started to get their drinking water from the aquifer below the city during the 19th century, concurrently with the public interventions to seal up the old canals, which were a threat to public health, promoting the spread of pathogens and epidemics. Since the second half of the century, the aquifer has been the only source of water for the city and its management has been assigned to the public utility Milano Metropolitana (MM) Spa since 2003. MM is run as a private corporation, but it is legally public as it is wholly owned by the municipality of the City of Milan. Additionally, it is regulated by the public authority Ufficio d’Ambito (ATO), which decides which tariffs to impose and which utility to entrust.
MM does not have problems in the extraction and provision of high-quality drinking water, given the local abundance of the resource. However, rising groundwater is increasingly causing floods and water infiltration in the underground structures of the city. The ground water table (i.e., the distance between the ground level and the underground water body) in Milan’s region has been steadily rising since the early 90s, now creating severe threats to several underground structures as for example the four metro lines. The ground water rise has been attributed to the economic system change that characterized the city of Milan during the 80s. Indeed, the city went from being a predominantly industrial urban area, to having an economy based on third sector services, which drastically reduced the water demand from the aquifer, earlier dominated by industrial use.
The recent groundwater rise, combined with the increase in (extreme) precipitation events due to climate change, require innovative management solutions to avoid continuous flooding and infiltration events, which are damaging and costly. Additionally, the rise in groundwater also poses the threat of contaminating the aquifer, since it encounters chemical elements which are more present in the upper strata. Because of such contamination, drinking water extraction already takes place at deeper levels of the aquifer, which are more pristine. Milan has the luck of having a reliable water source, therefore its protection and sustainable management should be of primary concern for the local authorities.
Bottom Line: Water abundance does not necessarily mean absence of water conflicts
* Please help my Water Scarcity students by commenting on unclear analysis, alternative perspectives, better data sources, or maybe just saying something nice 🙂