Flooding in Glendora, 1968
Photograph by Bruce Dale, published in National Geographic, October 1969
PAST, PRESENT, AND POSSIBILITIES
1960s
By 1970, construction of the Los Angeles Flood Control system, a network of regulation dams and concrete-lined rivers, was completed. Costing millions of dollars and with a construction schedule lasting nearly 40 years, rebuilding the Los Angeles River and its tributaries in concrete was the largest public works project in the United States. The effectiveness of this system was demonstrated during the winter of 1968-9, when Los Angeles experienced a storm meteorologists expect statistically once every 150 years. Although foothill communities suffered from mudslides, the lowlands of the valleys and coastal plains were spared from extensive flooding.