Iswari Shrestha has lived her entire life by the banks of the Bagmati as it flows south out of the Kathmandu Valley. Many people around her age in Nepal don’t know exactly how old they are, and the story is no different for Iswari. Her best guess is that she was born in 2010 on the Nepali calendar, which is 57 years ahead of its Georgian counterpart, making Iswari roughly 64 years old.

“When I was young,” she explains in raspy yet animated Nepali, “the River was alive. I grew up exploring, swimming, and fishing these waters.”

When Iswari was young, roughly 100,000 people lived in the three distinct Newar kingdoms of the Kathmandu Valley: Kathmandu, Bhaktapur, and Lalitpur. At that time, the nine tributaries to the Bagmati River flowed year round –cool and clean to the south, full of macroinvertebrates, fish, and frogs—towards their eventual union with the great Ganges River in India. The air was clean then too. The snow-capped Himalayas provided a picturesque backdrop for the merchants, artisans, priests, and farmers who called the Valley their home.

Even now, no one knows exactly how many people live in the Valley, though it is the subject matter of countless conversations shared by a diverse group of taxi drivers, students, shop owners, and politicians alike. If you sat in on these conversations, and you understood a bit of Nepali (plus the concept of the lahk - 1,00,000 or what most would call one hundred thousand), you would hear estimates ranging from 20 to 50 lahk, or between 2 and 5 million. Needless to say, a lot has changed since Iswari was young.

Currently, demand for water in the Valley far exceeds supply. To make up for the difference, groundwater is heavily pumped, causing a decline of the water table beneath the Valley. Scientists have long known that surface water and groundwater, though different in name, are really one resource, flowing where gravity and geology would have it. Now, however, man has left an indelible mark on Kathmandu’s waters. Among other impacts, the over-extraction of groundwater is progressively causing the springs and headwater streams, which the groundwater system once kept alive through the dry season, to go dry.

Simply put, these days many of the nine tributaries in the Valley never make it to the Bagmati. And assuming they did, they probably wouldn’t be too happy with what they found.

Two more generations of Iswari’s family now call the banks of the Bagmati River their home: Sabina, Iswari’s daughter-in-law, who is 25 years old (this is known for sure), Sabina’s older son Abusan, who is 7, and her younger son Asirbad, who just turned one. Sabina’s husband Roshan says you get used to the smell at some point, but visitors to the area might have their doubts. “The River is dead now,” Sabina laments as she nurses Asirbad in the courtyard of her home. Unfortunately, it wouldn’t be much of an overstatement to say that the Bagmati leaving the Kathmandu Valley these days is more of a sewage conveyance than a river.

Lots of good projects are underway to improve the water situation in the Valley. The Nepal River Conservation Trust hosts a Bagmati River cleanup each week, and recently celebrated its 100th week of cleanups. The High Powered Commission on the Bagmati River is busy laying large pipes along both banks of Bagmati, with the hopes of intercepting untreated wastewater before it contaminates the River. The Melamchi Water Supply project, funded by the Asian Development Bank, is an inter-basin water transfer program three decades in the making, which is supposed to come online within a year. Unfortunately, designs for the project were completed over 30 years ago, and even this newly imported water won’t be enough to bring the Valley into balance.

One common theme you’ll hear discussed among all who work on water issues in Nepal, or really anywhere in the world for that matter, is the growing need for good and accessible data. This is where SmartPhones4Water (S4W) comes in. S4W seeks to leverage the power of mobile technology and citizen science to enrich lives in the developing world by improving our understanding and management of water resources. Efforts are currently underway on the S4W team’s first pilot project in the Kathmandu Valley of Nepal (S4W-Nepal).

S4W-Nepal is a collaboration between S4W, Himalayan Bio-Diversity & Climate Change Center (HimBioCliCC), Kathmandu Institute of Applied Sciences (KIAS), Delft University of Technology, the Swedish International Development Agency, and Stockholm University. Water is our most precious resource. Lord Kelvin, a famous Scottish mathematician, once said, “You can’t manage a resource you don’t measure.” S4W-Nepal’s goal is to generate the data necessary to support wise water-management decisions. S4W aims to accomplish this with a three-pronged approach of Research, Education, and Employment.


Staff from S4W-Nepal met Iswari a few months ago while performing measurements of the water quality and water flow of the Bagmati just downstream from her house. Now Iswari’s daughter-in-law Sabina is playing a critical role in the project as a citizen scientist. Each day, Sabina uses an Android application called Open Data Kit (ODK) to record rainfall collected by an inexpensive ($1.50) locally-made rain gauge and the water level in the Bagmati river just below her house. Sabina is motivated to participate in the project because she feels a sense of responsibility to care for the river, and because each observation she makes earns her an extra 25 rupees (roughly $0.25).

Researchers from Delft University of Technology (TU Delft) and Stockholm University are interested in how citizen science data could be combined with remotely sensed data (e.g. data from satellites) to better understand the water system of the Kathmandu Valley. “Collecting data isn’t sufficient for solving the water problems in the Kathmandu Valley,” says the project lead Jeff Davids a PhD researcher with TU Delft, “ but it is absolutely necessary. We are enthusiastic about the possibilities of citizen scientists participating in primary data collection about water, especially in places where these data simply don’t currently exist.”

Recent advances in mobile technologies make smartphones a perfect tool for citizen science. Global Positioning Systems (GPS) and high-resolution camera technology embedded in smartphones can be leveraged to collect verifiable records in the field. Cellular networks and the internet can be used to transmit collected data to a central repository.

Questions about the reliability of citizen science data remain, however, especially in the minds of “professional” scientists and policymakers. To help answer at least one of these questions, Onset Bluetooth Low Energy Water Level Data Loggers are also being deployed at selected citizen-science water level monitoring sites. The Onset loggers measure water level at a preprogrammed interval of every five minutes, while citizen scientists like Sabina only take measurements with their smartphones once a day. The daily measurements will be compared to the continuous record from the data logger, as a proof of concept for the citizen-science methodology. What makes the Onset loggers unique is that Sabina can download the continuous data directly to her smartphone via a Bluetooth Low Energy connection, and send the data to S4W-Nepal staff via the local cellular network.

So far the results look promising. In support of a recent study the researchers published in Environmental Management, titled “Continuity vs. The Crowd - Tradeoffs Between Continuous and Intermittent Citizen Hydrology Streamflow Observations,” citizen-science observations of water levels in many cases appear to be good enough for several purposes, including water balance analyses.

“The HOBO MX2001 data Logger has the potential to cost-effectively monitor water levels in remote areas,” says Nischal Devkota, a fourth-year undergraduate environmental science student. “Depending on the questions you are asking, often daily citizen-science based measurements of water level are sufficient, but where continuous data is needed in remote areas, the Onset logger is our best bet.” Devkota has worked with S4W-Nepal for over a year, and is looking forward to being a catalyst for bringing citizen science to Nepal.

Funding for S4W-Nepal is provided by private donors in the United States and by the Swedish International Development Agency. Learn more at To sign up for S4W’s quarterly mailing list, go to and follow them on Twitter and Facebook. If you are interested in getting involved, please contact

Presented by
Jeff Davids


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