Access to clean water is probably the main fundamental human need whose sustainability issues are nonetheless often visible to travellers. Safety of the local water supply often features in travel guides for developing countries. It goes to show that large societies can function well with water availability, and even support tourism, yet the water quality may still be an issue.

Increasingly, as travellers seek more novel experiences, we also encounter water scarcity issues when we visit remote islands and deserts. Or at least, I do. Maybe I am predisposed to notice it because of my Bachelor’s degree, back when environmental engineering invariably meant civil engineering for water and wastewater infrastructure.

Being so essential to all life, paradoxically I have found that water issues typically already have a local solution. It may not be a great solution, but it is good enough. This is because, if they didn’t find one, they would no longer be there. After all, people settled at the location in the first place only after they found a source of water.

The problem happens when the source of water becomes insufficient, either due to population increase, or changes in the climate and hydrology. Or when the water source is no longer clean, due to sewage or other contamination (that’s one reason this SDG pairs clean water and sanitation together).

In short, this is an SDG that we tend to do ok in out of necessity, until sustainability issues in other SDGs mess it up. And because water is so necessary to life, water stress can then become the source of more issues in other SDGs, affecting everything from health outcomes, food security, economic activity, or even trigger war.