The Early Warning System of the Aburrá Valley (SIATA) operates more than 1,400 sensors, processes nearly 18 million data points per month, and generates hydrometeorological alerts that protect millions of people in the Medellín metropolitan area. But there is a gap that sensors alone cannot close: how many homes are truly at risk behind each alert? Where to prioritize when decisions must be made fast? Answering those questions requires a different kind of data, one that lives in the territory, in memory, and in the daily routes of those who inhabit it.

If you're not on the map, how can an alert protect you?

SIATA's education and outreach team discovered this in the most concrete way possible. Esteban Rivera, an environmental engineer on the team, describes it like this:

We looked up directions on Google Maps from Medellín to the rural school and there was no information about the territory. That made us question ourselves and rethink what kind of tools, digital tools, social mapping tools, could work for that. The school in question is located in Pantanillo, a rural settlement on the boundary between Barbosa and San Vicente Ferrer, less than an hour and a half from Medellín. A territory that belongs to the Metropolitan Area yet was invisible to conventional digital platforms. That invisibility has direct consequences: if we don't know where communities are, we also don't know how to protect them.

From analog map to open platform

SIATA's process doesn't begin with a screen. It begins with scale models of the Valley and local watersheds, with the task of asking parents what the territory used to look like, with hand-drawn maps. Rivera describes it:

We went step by step, naming the route from home to school. We had people place reference points: where they feel safe, where they recognize hazards, whether there have been floods, wildfires, landslides.

Only once that knowledge is activated does the process move to digital tools. The leap is not technological, it is one of recognition.

Today SIATA works with three open mapping platforms: the Tasking Manager to guide volunteers in Colombian OSM projects; Mapillary to visually document rural territories that don't exist on conventional maps; and ChatMap in complex urban contexts like La Honda neighborhood, on the eastern outskirts of Medellín. More than 100 people have been trained in these tools, and digital mapping now has its own formal module within SIATA's territorial strategy.

What the territory teaches the system

Three years of work with urban and rural communities, in Medellín, across the Metropolitan Area, in rural settlements with no internet connectivity or road access, have left SIATA's team with a deeper understanding of what it means to map in order to protect.

The lessons are technical, but they are also human. They have learned that not every territory allows for the same tools. They have learned that connectivity is an equity problem before it is a technological one. They have learned that when a student locates their home on a map for the first time and names the stream running through their neighborhood, something shifts in their relationship with risk. It is no longer something that happens to them — it is something they can read, and eventually anticipate.

Digital mapping is now a formal part of SIATA's strategies, with its own module within the territorial training program, including presentations, methodologies, and systematized results. But the team knows there is still a basic foundation missing:

We need more training. We have professionals who are willing to take a course, whether intensive or in another format, so that we can build more capacity in the use of digital tools and the relevance we can give them in educational and community settings.

Risk management in complex urban and peri-urban contexts depends, ultimately, on the quality of available information. SIATA has understood this since its founding and has built a technical infrastructure that few cities in the region can match. But technical information has limits where territory has not been named, mapped, or recognized.

The work SIATA is building is not a minor pilot project. It is a commitment to democratizing the production of territorial data, to recognizing communities as actors capable of generating intelligence for their own protection, and to building alert systems that reach where sensors alone cannot.

The Aburrá Valley has 1,400 sensors. And it also has communities that know their territory with a precision no sensor can replicate. The task is to connect them.

What is most remarkable about this experience is precisely what it did not require: a deep intervention from HOT. A couple of meetings and the participation of Esteban and other team members in some of our webinars were enough for SIATA, using those tools as a starting point, to take ownership of them and apply them directly in the field.

The results speak for themselves, and today SIATA's team is ready to bring these methodologies to more communities. Sometimes, the most valuable thing an open knowledge network can offer is exactly that: to spark the flame and let others carry it further.