Over the Bank
When people think of San Diego, they don't necessarily think of rivers. That's partly because many of the region's waterways are ephemeral, and they run underground for the majority of the year.
Yet, San Diego is part of an important, and increasingly threatened, watershed. There are hints of the water's power when local streams and rivers breach their banks during storm events. The overflowing water can close roadways and access to homes and businesses. The problem has gotten worse thanks to development encroaching onto floodplains.
(Related: "Deforestation and Its Effects on a Global Scale")
Let's take a brief tour of the San Diego area's unique watershed, and visit recent efforts to better protect it.
This story is part of a special National Geographic News series on global water issues.
Pictures: Reclaiming San Diego's Vital Rivers
Surrounded by desert and ocean, San Diego is watered by several rivers. They face threats from mining, pollution and overuse, but they also support important species, and occasionally still flood.