The narrow, cracked pavement that weaves into the densely tangled neighborhood along Jakarta’s Ciliwung River is still slick from the overnight monsoon storms. This vibrant cluster of life is called a kampung in Indonesian; the literal translation is “community” or “village.” But in Jakarta, the word is used to describe a slum neighborhood. On Google Maps, this one appears as just a blank gray swatch. After a twisting series of blind turns, the riverbank comes into view. The overnight deluge has raised the water enough to drown fifteen feet of shoreline. Flotillas of newly immersed trash churn in the intensified current.
For 52-year-old Ibu Atun, the water is literally at her doorstep. She’s lived in this community her whole life. Twice a month the water enters her house. When it’s really bad, her family takes refuge in the nearby school. Atun describes how the frequency of bad floods has increased over the past five years. In 2014, her house was completely submerged. She relies on flood warnings from the neighborhood leader — who receives a phone call from a floodgate operator upstream.
Home to more than 28 million residents, Jakarta and its surrounding metropolis is the second largest settlement on earth. Nearly three quarters of the city is prone to devastating seasonal flooding. Although they’ve been fighting the water for hundreds of years, unprecedented urbanization and climate change have brought the situation to a tipping point. And where traditional solutions are failing, an innovative use of technology is making a difference.
Around the corner, two younger residents are immersed in their smartphones, swiping through their social feeds. They admit to being on them all the time — and can’t imagine life without them. They explain how news of flooding often finds them through their phone.
These two encounters illustrate different ways in which people hear about (and share) news of flooding in Jakarta. Whether it be an announcement reverberating from the mosque loudspeaker, a phone call, the head of the neighborhood, their eyes or with social media — people don’t rely on just one single piece of information about flooding.

Jakarta has one of the highest concentrations of mobile devices and social media activity in the world. By combining these two things with the GPS features inherent to both, the city is tapping into a crowdsourced way of tackling its flooding problem that was not previously possible. They are leveraging something known as geosocial intelligence to make real-time flood maps fed by the social media of residents on the ground – which provides lifesaving information to individuals and emergency responders alike. It doesn’t involve costly, heroic construction projects or installing a vast array of new and expensive sensors along the exhausted canals and floodgates. Instead, open-source software elegantly taps into the on-the-ground knowledge residents have about flooding and turns it into a simple, up-to-date flood report. The emerging resource that geosocial intelligence offers is being realized in one of the most complex urban environments on earth. And what started as one small project is now proving itself as a model that can be used in global cities like Shanghai, Dhaka, Mumbai, Bangkok or even New York.