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      Department of Public Works Bureau of Sanitation

Where today stand high-density development and tightly packed communities crisscrossed by arterial freeways, Southern California was once a vast stretch of wide meadows and open space dotted by grazing cattle and sheep against a backdrop of majestic oak trees and rolling hills.

Despite Los Angeles’ relatively light annual rainfall, the area was prone however, to experience heavy rainstorms where property, livestock, and human lives were sometimes lost.

Historical research shows that a rain storm lasting 12 days occurred in the winter of 1851-52. Vineyards and orange groves that had been planted beside the Los Angeles River were washed away.

Ten years later, Southern California was ill-prepared for what is now known as the "Noachian deluge of California floods", a 40-day rainstorm that hit the area in the winter of 1861-62. The rain storm and subsequent drought afterward, caused the deaths of thousands of cattle which contributed to the financial ruin and eventual downfall of the "Californios."

With the resulting invasion of East coast immigrants as well as the lure of Gold Fever, Los Angeles’ population exploded while land values increased, and this open grazing land was soon replaced with buildings, homes and other development. Land became more valuable when sub-divided for commercial use, rather than for recreational, pastoral or farming purposes. This paving over of land resulted in rainwater not being able to be absorbed into the soil to replenish the groundwater table. Instead, when heavy rains now fell, as when another heavy rain in 1884, streets became flooded transportation corridors, and the need for controlling storm water became a major focus—and challenge.

The Rains Continue >

Even as recent as the 1930s, the San Fernando Valley was still open space as shown as this photograph.