New global database of dams and reservoirs could transform water management

A groundbreaking database developed by the Global Dam Watch  (GDW) consortium is set to transform the global understanding of dams and reservoirs.

Co-ordinated and led by members of a research lab at McGill University, with funding from World Wildlife Fund (WWF) and the World Bank, the database integrates existing global datasets to provide the most comprehensive resource for large-scale analyses to date.

River barriers, ranging from large dams to small locks, weirs, or barrages, play an essential role in water supply, flood control, hydro-electric power production and navigation, but also have ecological consequences, including fragmenting river ecosystems and disrupting sediment flow. With the GDW database, researchers and policy-makers can perform large-scale analyses of these trade-offs, leading to more sustainable and better informed water-management practices.

“The scale and depth of the data will facilitate analyses that were previously impossible, helping to strike a balance between harnessing water resources for human use and protecting the ecosystems that rely on these rivers,” said Bernhard Lehner, an Associate Professor in McGill’s Department of Geography, who oversaw the database project in his research lab over the past three years.

Of the 41,145 dams in the GDW database, 450 are in Canada, with over one-third of those built primarily for hydro power production. While these dams represent just one per cent of the records in the database, they impound some of the largest reservoirs in the world and provide about 11 per cent of the total global water storage capacity, highlighting Canada’s significant role in stewarding the world’s fresh water.

“This database provides a major step forward toward a comprehensive and consistent global database of river barriers and reservoirs. A wide range of hydrological and water resources analyses are now possible, with major implications for water resources management and conservation of freshwater systems — the lifeblood of humans and nature across the globe,” said Michele Thieme, Deputy Director of Freshwater at World Wildlife Fund.

The 41,145 barrier locations in version 1.0 of the GDW database are associated with 35,295 reservoirs, which create a cumulative storage capacity of 7,420 km³ and a new surface water area of 304,600 km². The data compilation also allows researchers, policymakers, and conservationists to assess the socio-economic and environmental costs and benefits of dams with unprecedented clarity.

“The Global Dam Watch (GDW) database consolidates the world’s largest open-access global datasets into a unified, comprehensive resource with consistent dam attribute information. Together with other tools available at www.globaldamwatch.org, its release aims to empower the community to enhance our understanding of the socio-economic and environmental costs and benefits of dams,” said Mark Mulligan, Professor of Physical and Environmental Geography at King’s College London and co-lead of the GDW consortium.

The project provided a diverse team of McGill undergraduate and graduate students with valuable practical experience; many students contributed significantly to the research and data-collection processes. In addition to those acknowledged as co-authors in the peer-reviewed journal article in Scientific Data, several others played important roles.

Researchers and policy-makers can learn more about the GDW database in Scientific Data and access the full dataset to gain valuable insights into these crucial water management systems here.