The economic slump still with us after several punishing years is largely rooted in living beyond our means — too much spending and not enough money in the bank to cover people’s expectations for the future.

This disconnect between actual and expected means is at the root of much of the financial markets’ distress. But it is also threatening another resource that modern society depends heavily upon: fresh water. If investors and companies do not plan for this already unfolding global threat, they are as vulnerable as overextended banks were when the housing bubble collapsed.

We live in a thirsty world. Climate change, population growth and pollution make quenching this thirst dramatically more difficult. Our over-leveraged global water position is fundamentally unsustainable, and the business community is already feeling the pain. Consider the following facts:

· In a recent survey backed by 354 institutional investors, 59 percent of the 100-plus largest global corporations report exposure to water-related risks, with over a third already suffering financial impacts.

· Ongoing drought in Texas has devastated cattle and cotton production and threatened power blackouts. The U.S. Department of Commerce reports drought-related losses in Texas and six neighboring states totaling $10 billion.

· New Chinese government figures show that 52 percent of the country’s industrial output — over $4.5 trillion in value — comes from regions facing serious water scarcity. Global banker HSBC warns that businesses operating in 14 water-scarce Chinese provinces need to plan for significant resource constraints. 

· A recent study led by McKinsey and the World Bank projects that by 2030 world water demand will outpace supply by 40 percent under a business-as-usual scenario.

Business as usual is already changing in significant ways for companies like Coca-Cola, which knows full well that a lack of sustainable water supplies is the ultimate show-stopper. With some 900 bottling facilities worldwide, Coca-Cola and its bottling partners depended on 295 billion liters of water in 2010 to drive $100 billion in revenues.

To put that in perspective, it’s less than half of what the city of Atlanta used last year. Yet beverage companies are a relatively small example of water-dependent industries. From farms to power plants, mining to microprocessors, water is indispensable.

But many in the private sector continue valuing water under stale assumptions: It’s seen as cheap, stable, and uncontested, when increasingly it’s none of those.