Toledo’s water crisis should be a wake-up call for innovators concerned about a water scarcity future. (Haraz N. Ghanbari/AP)

You can think of Toledo’s recent water problems as a microcosm for what’s happening around the world, where more than one billion people do not have clean water for drinking. For more than 48 hours, the 400,000 citizens of Toledo, Ohio were told not to drink their tap water out of fear that dangerous toxins from algae blooms in Lake Erie may have contaminated the water supplies. The governor even declared a state of emergency. Images out of Ohio didn’t look good – the tap water looked like a green juice drink you might get after a workout, prompting a run on bottled water supplies in Ohio and Michigan.

While Toledo’s water emergency may seem like an isolated incident, it’s actually a symptom of a broader problem known as global water scarcity. There’s still time to act before we get into the really worst-case scenarios, but it’s clear that “water innovation” — for lack of a better term – is going to become an increasingly important topic over the next two decades. The UN has already predicted that water scarcity will be one of the defining issues of the twenty-first century, and many have suggested that we could be facing a global water crisis by 2040.

That means that we will need to create new types of innovations to solve the water crisis that go well beyond nifty filtration innovations originally intended for the developing world. We will need to rethink entire industries.

That’s because many of the causes of Toledo’s water crisis appear to be man-made rather than the result of some unexplained drought or other natural disaster. Water researchers and environmental groups have warned of the potentially hazardous effects of dumping farm runoff and sludge from sewage plants into Lake Erie. Actions taken over an extended period of time are now catching up to us. Lake Erie provides drinking water for 11 million people — that’s approximately 1 in 30 Americans. It would be naive to think that what happened in Lake Erie is not happening elsewhere around the nation.

One area where innovators could have a major impact is the power generation industry. According to a recent report on the looming global water crisisslightly more than 40 percent of all water used within the United States is used for thermoelectric cooling. In other words, 40 percent of all water within the United States is not used for drinking, brushing teeth or taking long showers — it’s for cooling the excess heat generated by coal and nuclear facilities that provide us with electricity. It’s easy to see how a shift to renewable energy sources such as wind and solar energy could become a powerful water-conservation tool, especially for drought-prone states such as Texas.

Agricultural production, too, is an area ripe for innovation. In most parts of the world, agricultural production accounts for a significant share of all water use. Short of asking humans to scale back on the amount of fruits and vegetables they consume, we are going to need new ways of farming and crops that aren’t as water-intensive or that take advantage of innovative new techniques for “agricultural water management.” According to the World Bank, this might mean anything from subsurface irrigation technologies to weather forecasts delivered by SMS to farmers in the field.

If the water crisis persists, attempts at water recycling should also get the green light. Who can forget the efforts by the government of Singapore to create a method for the recycling of toilet water into drinkable water? In fact, according to the World Water Council, recycled sewage will be a source of drinking water in cities around the world within the next three decades. While the idea of drinking “recycled water” doesn’t yet have the cachet of drinking a bottle of Evian, there are other innovative water-recycling concepts that just might work — like a shower created by a Swedish industrial designer that saves 90 percent of all water used.

The really big idea, of course, is coming up with a cheap, efficient desalination technique to transform the world’s salt water into fresh water. The earth has much more salt water than fresh water, so that idea has always attracted the attention of innovators. Desalination, however, is one of those ideas that gets people worked up — scientists claim that there’s no way of doing it without burning a tremendous amount of fossil fuels. For now, it simply requires too much energy to do cheaply or efficiently.

Both the UN and the OECD have already warned that the twin effects of population growth and global climate change could lead to nearly half of the world’s population facing a water crisis within the next twenty years. In a worst-case scenario, that scarcity might lead to wars for access to the earth’s water supplies. That almost sounds like a science fiction plot out of a dystopian young-adult novel, until you realize that it could be a reality if our nation’s leaders don’t take the warning signals seriously. You can think of Toledo’s water crisis as a wake-up call for America’s water innovators.