Sixty years ago, the Los Angeles River wound untamed from its origins above the San Fernando Valley through downtown Los Angeles, and emptied into the sea at Long Beach.
Beginning in the 1930s, however, the Army Corps of Engineers began lining the river channel with concrete to control the flooding that regularly devastated parts of Los Angeles and the Valley and to prevent the waterway from changing course and flowing into inhabited areas after heavy rains.
About 45 miles of the 52-mile river have now been bounded by concrete. But a stretch of the river along Sepulveda Basin continues to look much as it did 60 years ago.
Although Los Angeles plans to add even more concrete to the river's end in Long Beach, conservationists hope that most of the waterway will return to its more pristine state if the city follows the lead of other major cities, which use newer flood-control techniques. These include using collection basins, and restoring the natural river bottom to increase seepage into the water table to avoid flooding.