19th August 2026
For much of human history, rivers have seemed almost indestructible. They rise in mountains, flow through valleys, cross borders and eventually reach the sea. Civilisations have been built beside them precisely because they appeared to provide a dependable source of water for drinking, farming, transport, industry and energy.
But that assumption is beginning to look increasingly dangerous.
The Colorado River has become the symbol of what can happen when human demands grow beyond what a river can reliably provide. For decades, water has been diverted from the river to supply cities, agriculture and industry across the American Southwest. The river has been so heavily managed and exploited that in many years little or no water reaches the Gulf of California in the way it once did.
And yet the Colorado may no longer be an isolated warning from a dry corner of the United States. Rivers across Europe are now showing signs of the same underlying problem, while climate change is making the amount and timing of available freshwater increasingly uncertain.
That is why the summer of 2026 deserves rather more attention than another story about heatwaves and drought.
The European drought situation has become serious enough for major rivers including the Rhine, Danube, Loire and Po to experience exceptionally low flows. The consequences extend well beyond the environment. Low water levels affect agriculture, shipping, energy generation, industry and the availability of water for communities.
Britain has not escaped the wider pattern. Official monitoring in England during July showed that 84 per cent of monitored river-flow sites were below normal or lower, while reservoir storage had fallen to 75.3 per cent and soil moisture deficits had reached record levels for the time of year across large parts of the country. Almost 40 per cent of England's population was facing water-use restrictions at that point.
This is not simply a question of whether people can water their gardens.
Water is an economic resource. A farmer needs it to grow food. A food processor needs it to operate. A power station needs it for cooling. A whisky distillery needs reliable water. A factory needs it for manufacturing. A town needs it for drinking and sanitation. A river ecosystem needs enough flow to survive.
The difficulty is that all of these demands arrive at the same time.
For decades, many countries have dealt with water shortages as though they were temporary interruptions. A drought arrives, restrictions are introduced, reservoirs fall, governments appeal for people to use less water and eventually the rain returns.
But that approach becomes much more difficult when the underlying climate is changing.
The United Nations World Water Development Report continues to emphasise that water insecurity is a global problem affecting households, agriculture, industry, energy and ecosystems. The 2026 report also stresses the enormous social and economic consequences when reliable access to water cannot be guaranteed.
There is another problem which is less visible than a shrinking river.
Groundwater is ofen overlooked. When rivers and reservoirs run low, agriculture and communities often turn to groundwater. That can provide an extremely useful buffer because aquifers can store water underground for months, years or sometimes centuries.
But an aquifer is not an unlimited underground reservoir. If water is extracted faster than rainfall can replenish it, the apparent security is temporary. The water may continue coming from the tap or irrigation system while the resource underneath is quietly being depleted.
This is one reason the Colorado River story is so important. The problem is not simply that there is less rainfall. It is that an entire economic system has evolved around the assumption that a particular quantity of water will be available.
Once that assumption becomes unreliable, somebody has to lose.
Farmers may have to plant less water-intensive crops. Cities may have to restrict consumption. Industry may face higher costs. Environmental flows may be reduced. Governments may have to decide which users receive priority.
And eventually those decisions become political.
The Colorado River is now entering another important phase because the rules governing its post-2026 operation are being renegotiated. The US Bureau of Reclamation's current process involves the seven basin states, tribal nations and Mexico because the existing arrangements are reaching the end of their scheduled life.
That is a remarkable situation. A river system which crosses several states and an international border has become so stressed that its future has to be redesigned through a major political and legal negotiation.
Europe may not be facing exactly the same circumstances, but the lesson is applicable.
We cannot simply look at a river's average annual flow and decide that there is enough water.
What matters is when the water arrives.
A river can carry enormous quantities of water during winter and spring but still become critically low during the growing season. A reservoir can fill after heavy rainfall and still fail to provide sufficient water through a prolonged summer. An aquifer can appear healthy until years of excessive extraction begin to catch up.
Climate change makes this timing problem more difficult because warmer temperatures increase evaporation and increase the amount of water that plants and soils require.
This creates an uncomfortable possibility.
We may not necessarily be heading towards a world in which every river simply becomes smaller. We may instead be entering a world in which rivers become less reliable.
That distinction is crucial.
A river which is occasionally extremely low can be more economically disruptive than one which is consistently modest but predictable. Farmers, shipping companies, power generators and businesses can plan around predictable water supplies. They struggle when the conditions swing from abundance to scarcity.
The Rhine provides a good European example. It is one of the continent's great industrial waterways. When water levels fall, ships cannot carry their normal loads and more goods have to be transported by road or rail. The consequences eventually reach companies and consumers far away from the river itself.
Water scarcity can therefore become an inflationary problem.
Food becomes more expensive because crops are harder to produce. Transport costs rise. Electricity generation can be affected. Businesses have to invest in water efficiency and alternative supplies. Governments may have to spend billions adapting infrastructure.
And then there is the environmental cost.
A river is not merely a pipe carrying water to human beings.
Fish, insects, birds, wetlands, forests and entire ecosystems depend upon particular patterns of flow. If too much water is removed, the river can remain technically alive while becoming ecologically impoverished.
This is where the debate becomes particularly important for Scotland.
It would be easy to dismiss the problem because Scotland generally has far more rainfall than many parts of England or southern Europe. The Highlands in particular are not the Colorado Desert.
But climate change does not require Scotland to become dry in order for water security to become an issue.
What matters is variability.
If Scotland receives more intense rainfall but longer dry spells, more water can run rapidly off the land and into the sea while less is retained in the soil and groundwater. A wetter country can therefore still experience periods of water stress.
That should change the way we think about water.
For too long, water has been treated as something almost free and almost limitless. We turn on the tap and expect it to work. We flush the toilet and the problem disappears. Industry draws water from rivers and aquifers and the wider public rarely sees the resource being consumed.
But the water is not disappearing.
It is being moved, used, polluted, evaporated or removed from systems faster than nature can sometimes replace it.
The great danger is that governments wait until shortages become obvious before acting.
By then, the cheapest solutions may have disappeared.
Building reservoirs, restoring wetlands, improving leaking infrastructure, changing agricultural practices, protecting aquifers and improving water efficiency all take time. They are much easier to undertake before a crisis than during one.
There is also a wider lesson from the Colorado.
Nature does not negotiate.
If a river historically provides a certain amount of water and human society builds commitments around a larger amount, eventually mathematics wins.
The argument between farmers, cities, industry and environmentalists may continue for years, but the river itself cannot produce water simply because more people have acquired rights to use it.
That is why I believe the water story deserves to move much higher up the political agenda.
We have become accustomed to thinking about energy security. We understand that countries need reliable supplies of oil, gas and electricity. We increasingly talk about food security and the need for resilient supply chains.
Perhaps we need to start talking about water security with the same seriousness.
Because without water, agriculture fails, industry struggles, energy systems become vulnerable and communities suffer.
The Colorado River has been warning us for years.
The rivers of Europe may now be adding their voices.
And Britain should probably listen before it discovers that being a wet country is not the same thing as having an unlimited supply of usable water.