How Montevideo used data to protect residents during a water scarcity crisis

Montevideo, the capital of Uruguay, invested in citywide data governance, capacity, and transparency through its participation in the City Data Alliance (CDA). These foundations proved critical when the city faced an unprecedented water scarcity and water quality crisis in 2023. As prolonged drought and elevated sodium levels made tap water unsafe for consumption, Montevideo used data to monitor water quality, target support to vulnerable residents, and communicate transparently with the public. By activating the Data Committee and data practices established through CDA, the city reduced uncertainty, prioritized equity, and ensured residents had the information and support needed to make safe decisions during a moment of crisis.

Clean drinking water is central to daily life and public trust in Montevideo. When residents began reporting an unusual taste in tap water, city leaders recognized that the challenge was not only technical but also deeply human. Pregnant women, older adults, and people with chronic health conditions faced elevated health risks, and fear spread quickly.

Mayor Carolina Cosse and her team set a clear objective: provide residents with certainty in a moment of crisis and act quickly to protect residents. This meant giving people timely, neighborhood-specific information on water safety, ensuring alternatives for those at highest risk, and using data to guide decisions throughout the response.

Montevideo’s response was powered by institutional capabilities built during CDA, particularly the creation of a cross-departmental Data Committee and a citywide data strategy focused on governance, data quality, capacity, use, and transparency. When the crisis emerged, these structures were activated immediately. Working alongside the municipal Emergency Committee, the Data Committee coordinated a response around three priorities:

1. Neighborhood-level water quality data, published fast: The city systematically tested water quality across Montevideo, collecting hundreds of samples from municipal health centers and analyzing both tap water and bottled water sold to residents. Water from public and community-provided wells was also assessed. Rather than relying on aggregated national data, Montevideo published disaggregated, neighborhood-level results so residents could understand local conditions.
2. Targeted support for residents most at risk: Using existing social and health data, the city identified residents vulnerable to elevated sodium levels, including pregnant women, older adults, and people with medical conditions. Data was used both to identify these groups and to track whether coordinated support reached them. Bottled water was distributed through health centers and, when needed, delivered directly to residents’ homes to overcome geographic or mobility barriers.
3. Clear, consistent, and inclusive communication: City leaders understood that data alone would not reduce anxiety unless communicated effectively. Montevideo shared information through the city’s open data platform, printed materials in health centers, and WhatsApp flyers to reach residents with varying levels of digital access. Daily updates explained water quality results, health guidance, and available support.

Montevideo’s data foundations enabled faster, fairer, and more transparent action during the crisis:

• Reduced uncertainty: Neighborhood testing covered all 15 municipal health districts, with more than 500 samples collected and published so residents could see local conditions.
• More equitable support:Vulnerable residents were identified using social and health records. Data was then used to verify that aid reached those most in need.
• Stronger public trust: The city digitized and published national utility data alongside its own results, increasing transparency and enabling residents to track conditions.

After the national government declared the end of the emergency, Montevideo committed to continuing water quality monitoring and public reporting, embedding lessons from the crisis into ongoing operations.

Montevideo’s experience shows that strong data foundations create resilience and care for residents when it matters. Publishing disaggregated, neighborhood-level data builds trust where conditions vary, and equity requires verification to ensure support reaches those at highest risk. Clear, consistent communication is integral to data work, because information only creates impact when people can understand it. By activating the Data Committee and established governance, Montevideo turned crisis practices into institutional routines, demonstrating how cities can use data not only to manage systems but to protect people.