"A once-unthinkable day is looming on the Colorado River. Barring a sudden end to the Southwest’s 11-year drought, the distribution of the river’s dwindling bounty is likely to be reordered as early as next year because the flow of water cannot keep pace with the region’s demands."

"Federal officials began a sweeping crackdown on pollution in the Chesapeake Bay on Friday - threatening to punish five mid-Atlantic states with rules that could raise sewer bills and put new conditions on construction."

Egypt's 80 million people have always depended on the Nile River. Under a 1929 treaty, 80 percent of the river's flow is reserved for Egypt and Sudan, which were then ruled as a single country. Now the seven upstream countries (Ethiopia, Uganda, Tanzania, Kenya, the Democratic Republic of Congo, Burundi, and Rwanda) want to revise the treaty, calling it an unfair relic of colonialism.

"Great Lakes pollution is getting worse because sewage systems are outdated and Ontario’s north is turning into a Wild West for miners and forestry companies, warns Environmental Commissioner Gord Miller."

"The oil giant nears an agreement to dispense $500 million through an alliance overseen by gulf state governors. Critics fear expertise elsewhere will be overlooked."

"A new generation of prospectors is eager to explore the ocean floor. Will deep-sea digging damage one of the earth’s most valuable ecosystems?"

"A number of the playful marine mammals are being poisoned by an ancient microbe that appears to be on an upsurge in warmer, polluted waters around the world."