The Sustainable Development Goals (SDGs) recognise the sustainable management of freshwater resources as a global challenge. Target 6.5 calls for the implementation of integrated water resources management, and Target 6.6 for the protection and restoration of water-related ecosystems. UN Water recognises that “mismanagement combined with climate change is devastating many ecosystems”.

But the trouble with the SDGs is that they can and do conflict with each other. For example, goal 7 addresses the need for affordable clean energy, 13 the need for action to combat climate change, and meeting both demands requires a shift to renewable energy. 

Hydropower dams have become central to green energy investment programmes, both to supply grids and to meet shortfalls in solar or wind supply. In fact, there has been a global surge in dam building in the name of green energy. 

Yet dams remain controversial. 

They demand lots of energy-guzzling concrete, and their reservoirs are a significant source of methane, a potent greenhouse gas. They also cause significant environmental and social impacts, both upstream (where people and wildlife are flooded) and downstream, where floodplain ecosystems and communities are starved of former floodwaters, or threatened with sudden flood flows as energy grids demand power. 

So, dams offer no easy solutions to the challenge of sustainably managing freshwater resources. Is it possible to make use of rivers’ waters without negative impacts? Yes, and in fact clear guidelines for doing just this were set out more than two decades ago by the World Commission on Dams in its report, Dams and Development, published in 2000. 

The Commission’s starting point was simple, although significant: before any dam is conceived, the need for water and energy services and alternative ways to address them must be assessed (rather than assuming a dam is needed and looking for a place to put it). They suggested that all planning must be based on decentralised and participatory consultation processes with all affected people (downstream as well as up). Above all, dam projects should turn losers into beneficiaries, with their operation contingent on the implementation of specific benefit sharing and mitigation measures.

Sadly, the Commission’s recommendations were not universally welcomed by the dam-building world. Its ideas were taken up by some countries (e.g. Germany), but shunned by others (e.g. China and India, although equally by the World Bank). The Commission’s ideas have been allowed to drop out of the thinking of today’s dam planners. 

It is easy to say we must “sustainably manage freshwater ecosystems”, but it is less easy to do. New dam projects continue to be proposed, planned and built that damage freshwater ecosystems and negatively impact the lives and livelihoods of floodplain people. Such dams may reflect good intentions about energy transition, but are not well conceived. Dam planners might need to learn from the past to build for the future.

Read more on "Addressing conflict over dams: The inception and establishment of the World Commission on Dams".