Journey to Planet Earth examines the health of four of the world's river systems — the Mississippi, the Amazon, the Jordan and the Mekong. The first stop is the small town of Grafton, Illinois, one of the many to suffer devastating damage when the upper Mississippi River flooded its banks in 1993. Journey to Planet Earth shows how massive construction efforts earlier in this century to control the river's flooding have profoundly affected the entire Mississippi basin.

In Brazil, fish snatch fruit from the boughs of trees along the Amazon River deluged with up to 30 feet of flood water during the six-month rainy season. It is a vast, enchanted underwater forest supporting an incredibly diverse ecosystem. But recently, settlers have plundered these flooded rain forests at an alarming rate. Journey to Planet Earth visits the village of Sao Miguel where fishermen, ranchers and farmers have begun working together to preserve the integrity of the river's natural resources.

Compared to the mighty Amazon, the Jordan River is an insignificant trickle, but to the desert nations through which it flows, it is all-important. Journey to Planet Earth visits an Israeli kibbutz along the Sea of Galilee, where the river's waters have brought prosperity. They also visit the parched West Bank of Palestine and the biblical city of Jericho whose Arab inhabitants, denied access to the Jordan River, must make do with ancient springs and meager supplies of underground water. As former Israeli Prime Minister Shimon Peres said in an interview, "the equitable distribution of water may prove to be the only key to a lasting peace in the Middle East."

In Vietnam's tropical Mekong Delta, we visit a society long dependent on the river's bounty. Decades of regional war and political unrest have left the Mekong one of the least developed rivers of Asia. But peace and prosperity are now bringing change to the Delta, not all of it beneficial.

The last stop is the city of New Orleans, whose very existence is a testament to human engineering ingenuity. Not long ago the Army Corps of Engineers stepped in when the Mississippi threatened to change course away from New Orleans. The city's economy was saved but Journey to Planet Earth investigates the devastating consequences to the Mississippi Delta where 25 square miles of coastland are now lost to the Gulf of Mexico each year. Now Louisiana's bayous are turning into salt marshes and open water, and the Cajun way of life is fast disappearing.