Water flows through these pages.

In our cover story, Patagonia Under Siege, OnEarth articles editor George Black files a report from Chile that is rhapsodic, alarming, and eye-opening. Black describes a country blessed with a galloping economy but hungry for energy to fuel its development. With no oil or natural gas of its own, Chile is now looking to hydropower. Much of the country's wealth, meanwhile, comes from salmon farming -- Chile's second-largest export industry, just behind copper. This means that a great deal of the nation's economy depends on water, which cascades and flows abundantly through the Patagonian wilderness, where there are many rivers to be dammed, many fjords to be farmed. Can this Edenic landscape survive Chile's success? The answer is yes -- all it takes is a smart, sustainable plan for energy and economic growth, a notion some of the country's leaders are beginning to grasp. Other burgeoning economies in South America and elsewhere face dilemmas similar to Chile's, so Black's story offers lessons that apply far beyond the borders of this particular paradise.

Elizabeth Royte tracks the flow of water in a different direction, closer to home. She travels to the Heritage Village retirement community in western Connecticut, on the banks of the Pomperaug River, to trace the unexpected course that pharmaceutical products travel. Royte points out that Americans fill three billion prescriptions a year. Even after we take our antibiotics, our antihypertensives, our painkillers, our antidepressants, these drugs persist: They move through our bodies into sewage systems and thence to our waterways. Unused medicines, when disposed of, travel a similar route. Once these still-active pharmaceutical agents find their way to a river, they can flow downstream to communities that may drink from its waters. That's why scientists like Allison MacKay at the University of Connecticut are so eager to study the Pomperaug, whose proximity to Heritage Village makes it an ideal site for investigating the impact of prescription drugs in our water. Much research must still be done before we understand the exact nature of the risks, but I for one am glad that MacKay and her colleagues are on the case. You will be too, after you read Royte's provocative, thoughtful story.

Finally, author Jacques Leslie takes a more global view of water in his rumination on Fred Pearce's new book, When the Rivers Run Dry: Water-The Defining Crisis of the Twenty-First Century. Severe water shortages already afflict hundreds of millions of people around the globe. Global warming, writes Leslie, will only exacerbate the problem-and bring it much closer to home. He urges us to grapple with this immense challenge before it's too late.

In an essay by Bill McKibben, we are given new reason to believe that climate change can be successfully confronted; he offers a reflection on the conversion of evangelicals who see the issue now as a moral imperative. Finally, an essay by Alison Hawthorne Deming offers a gorgeous ode to one of the continent's most magnificent winged predators -- and reminds us why we long so passionately to protect creation.

Douglas S. Barasch