Dam safety |
by the authors. While the DAM-IN dataset focuses on assembling consistent, catchment-scale information to support hydrological, environmental, and dam safety studies in India, it also highlights the broader context in which such data are applied. The use of detailed physical, climatic, and anthropogenic attributes becomes most relevant when embedded within established regulatory, institutional, and operational frameworks.
Dam safety management in Japan Japan has developed one of the most comprehensive
dam safety management systems in the world, shaped by a combination of challenging natural conditions, dense downstream populations, and a long history of water infrastructure development. The World Bank report Dam Safety Management in Japan (2025) documents the country’s legal, regulatory, institutional, and operational approaches to dam safety, with the objective of sharing practices and lessons that may be relevant for other countries seeking to strengthen their own dam safety assurance systems. The report does not present a prescriptive model but
Above: Honen’ike Pond Dam in the Sanuki Mountain range at Kan’onji, Kagawa Prefecture, Japan. The structure dates from 1930
footprint values were sourced from the Global Human Footprint dataset. Night-time light intensity was derived from the DMSP-OLS satellite products, using stable light composites. Population counts were taken from the Gridded Population of the World dataset for the year 2020. These indicators show that many dam catchments experience moderate levels of infrastructure and human activity, although population density and night-time light values remain low in a large proportion of catchments. The authors note that global datasets were used for some indicators due to the lack of consistent regional alternatives, and they acknowledge that this may introduce uncertainty.
Data access and intended use The complete DAM-IN dataset is hosted on Zenodo and
is organised by river basin and individual dam catchment. Each catchment folder contains static attributes and time- series data in standard formats. The authors also provide code used to generate the dataset. Validation was conducted through spatial comparison of derived attributes with source datasets to ensure consistency in regional patterns. The study does not include independent field validation or performance benchmarking. The authors state that the dataset is intended to support hydrological modelling, dam safety analysis, reservoir management studies, environmental assessments, and climate risk analysis. They emphasise that while the dataset enables such work, it does not itself evaluate dam safety or operational adequacy. The DAM-IN dataset represents a national-scale
effort to consolidate diverse geospatial and temporal information relevant to dam catchments in India. By integrating topographic, geological, soil, land use, climatic, and anthropogenic attributes into a single, open- access resource, the study provides a data foundation for future analysis rather than prescriptive conclusions. For the international hydropower and dam safety community, the dataset offers a detailed example of how large-scale catchment characterisation can be assembled using existing data sources. Its value lies in standardisation, transparency, and accessibility, while its limitations – particularly those related to data resolution and source consistency – are clearly acknowledged
32 | January 2026 |
www.waterpowermagazine.com
instead describes how Japan’s system has evolved over time in response to floods, earthquakes, water scarcity, and changing socioeconomic conditions. It situates dam safety within a broader framework of integrated water resources management, emergency preparedness, and public safety. Japan has more than 3100 large dams, defined as dams with a height of 15m or more, or dams between 5 and 15m that impound more than 3 million m3
of large dams, after China, the US, and India. In addition to large dams, Japan has more than 150,000 irrigation ponds, of which approximately 61,000 serve irrigation areas larger than 2 ha. Around 70% of these ponds were constructed during the Edo period (1603–1868) or earlier, before modern regulatory frameworks. The majority of large dams in Japan are irrigation and multipurpose dams, followed by hydro dams. In terms of structural type, concrete gravity and earthfill dams dominate, with rockfill and arch dams also widely used. .
Natural and socioeconomic context The report emphasises that Japan’s dam safety
framework cannot be separated from its natural and human geography. Approximately 70% of the country’s land area is mountainous or hilly, resulting in rivers that are generally short, steep, and prone to rapid flow. These characteristics increase flood risk and complicate reservoir operation and sediment management. Japan is also located on the Circum-Pacific seismic belt. According to data cited in the report, around 20% of the world’s earthquakes with a magnitude greater than 6 occur in or around Japan. In addition, the country experiences heavy rainfall associated with monsoon systems, seasonal rain fronts, and typhoons. Large metropolitan areas, including Tokyo, Osaka, and Nagoya, are located on floodplains downstream of major river systems and account for a high proportion of the national population and fixed assets. These conditions have driven the development of stringent design standards, operational rules, and emergency management practices for dams..
Historical development of dams The construction of dams in Japan spans more than two
millennia. Early dams and ponds were primarily built for
of water. This places Japan fourth globally by number
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45
