Blog post by Michiel Jorissen, FIRE Lab collaborator
A few weeks ago, Steph invited me – as a citizen scientist on the GROD project – to join and contribute to the Global Dam Watch workshop held at WWF headquarters in Zeist, Netherlands. It was lovely meeting Steph in person after playing #damornot on Twitter for years. It was also great to contribute to discussions, and projects that aim to improve data for communities, scientists, and others working on global challenges related to dams, and freshwater ecosystems.
Water is a vital resource for nature and society. It is used for drinking, irrigation, power generation and storage, navigation, and waste disposal. Vast amounts of water are stored in Earth’s oceans, but for sustaining life, fresh water is required, and only a small fraction of our water is fresh. All the readily available fresh water in the world would fit in a sphere with a diameter of just 56.2 km (USGS, 2019). The scarcity of fresh water as a resource limits the amount that is sustainable for use by people. Despite this, most countries treat fresh water as a purely functional and unlimited resource and have even externalised their water footprint to other countries as well (Hoekstra & Mekonnen, 2012).
Already water shortages are reason for conflict, and further complicated by changing climate and human populations (Petersen-Perlman, Veilleux, & Wolf, 2017). Humans have adapted to life in areas otherwise inhospitable due to lack of reliable and sufficient fresh water supplies by building dams. Additionally, dams can also provide hydroelectric power and be used for flood control. However, these benefits also come with a price. Construction of a reservoir leads to flooding of prime riverside land, displacement of people and wildlife living in an area, human health risks, greenhouse gas emission, and changes in sedimentation and water flow with impacts on entire ecosystems.

Encinarejo Dam, Río Jándula near Andújar, Spain (Photo: Michiel Jorissen, 2016)
I always assumed people would have maintained a database of all these dams and their defining features, especially considering the hundreds of millions of people relying on dams for their water needs. Last week, I learned there isn’t even a reliable estimate of the total amount of dams in the world. Furthermore, whether a structure should be called a dam is still up for debate and when a fresh water body is a lake, or a reservoir isn’t clear either.
Luckily, some of the world’s brilliant minds are working on this caveat in creative ways. Using “brute force” by visually checking rivers in aerial imagery for obstructions, utilising artificial intelligence and machine learning to detect structures in this imagery automatically and using geographical data and statistical models to predict the presence of dams and reservoirs. Finding out where water flow is altered is key to solving global fresh water challenges. I hope all these combined efforts will lead to a sustainable access to freshwater in the future.
Thank you for reading! Next week the FIRE Lab team will be sharing thoughts and reflections from their recent What Is Water? event. If you would like to connect with me, I am @MichielJorissen on Twitter.
References
USGS. (2019). How Much Water is There on Earth? https://www.usgs.gov/special-topic/water-science-school/science/how-much-water-there-earth?qt-science_center_objects=0#qt-science_center_objects
Hoekstra, A. Y., & Mekonnen, M. M. (2012). The water footprint of humanity. Proceedings of the National Academy of Sciences, 109(9), 3232–3237. https://doi.org/10.1073/pnas.1109936109
Petersen-Perlman, J. D., Veilleux, J. C., & Wolf, A. T. (2017). International water conflict and cooperation: challenges and opportunities. Water International, 42(2), 105–120. https://doi.org/10.1080/02508060.2017.1276041