Water shortages and floods illustrate the risks posed by too little, or too much, water. By 2050 more than 40% of the world’s population will live under severe water stress and nearly 20% could be exposed to floods. The economic value of assets at risk from floods is expected to be about USD 45 trillion by 2050. Water pollution is also increasing, adding to uncertainty about future water availability.

These water risks are exacerbated by climate change. Governments must manage them, so they do not jeopardise growing populations and cities, economic growth and food or energy security.

“Instead of just reacting to water crises, governments must assess, target and manage water risks proactively”, urged OECD Secretary-General Angel Gurría. ”We have been forewarned - there is no doubt these risks are increasing. We must now arm ourselves with risk management strategies that will prevent water shortages and pollution and protect against the droughts and floods that are endangering human lives, ecosystems and economies.”

OECD’s new report Water Security for Better Lives sets out a pioneering risk-based approach to water security and proposes practical steps to implement it.

The report notes that water security is ultimately about establishing an acceptable level of water risk by weighing the costs of improving water security against the expected benefits, and ensuring that responses are proportional to the magnitude of the risk. Flexibility is important, allowing acceptable levels of risk to be adjusted to changing situations. For instance, New York City is reassessing its flood protection level following Hurricane Sandy and investing billions to avoid future disasters.

Using this risk-based approach, another new OECD report Water and Climate Change Adaptation: Policies to Navigate Uncharted Waters reviews countries’ initiatives to adapt water management to climate change. It reveals that nearly all countries project increasing water risks due to climate change, with extreme events (floods and/or droughts) cited as a primary concern by 32 countries and 23 saying water shortage is a key issue.

About half the countries surveyed noted that climate change impacts on water supply and sanitation are a key concern, with a similar number highlighting concerns about the impacts on water quality. Though countries are building the evidence base to inform decisions about water risks, faced with the impacts of climate change, they should do more to better target and manage them.

Besides their obvious relevance for policy makers in the fields of water and of climate change, these two publications will be key OECD contributions to the Stockholm World Water Week taking place from 1-6 September.