The Los Angeles River watershed, 1800 ENLARGE

PAST, PRESENT, AND POSSIBILITIES

1800s

1910s

1930s

1960s

1990s

The above map illustrates the indigenous geographic features of the Los Angeles River Basin. The expansiveness of the flood plain indicates the instability of the river channels in their natural state. For example, until 1815 the Los Angeles River reached the Pacific Ocean via Ballona Creek just north of the present-day airport. The San Gabriel River also meandered across the coastal plain, choosing the Rio Hondo as its main channel to join the Los Angeles River in its course to the Ocean prior to 1868.

Some basic facts about the watershed:
Total area: 2114 square miles
Non-mountainous area: 1100 square miles = 52% of watershed
Flood plain: 420 square miles = 38% of non-mountainous area

Understanding the natural characteristics of the Los Angeles River helps explain why today's downtown skyscrapers are located twenty miles inland and not on the coast or around either the San Fernando or San Gabriel Mission. In Los Angeles, like most cities, downtown is the location where the city first began. Founded in 1781 as an agricultural village to supply the Spain's California outposts, El Pueblo de la Reina de los Angeles required land suitable for cultivation that could be irrigated by gravity with a steady, year round flow of water. This could be found in only one location in the entire river basin: near the Glendale Narrows, where the Los Angeles River turns south from the San Fernando Valley to pass through the Santa Monica Mountains. On the sandy soils of the valleys and coastal plains, the river frequently disappeared underground during the summer, but the rocky base of the mountains forced the river to the surface throughout the year. Thus the Pueblo of Los Angeles was situated adjacent to the river south of the Elysian Hills. Yet it seems the Spaniards misjudged the river's capriciousness and capacity to overflow its banks, for evidence suggests that the pueblo church and plaza were moved to higher ground following flooding in 1815.

Because the rivers in their natural condition constituted a single hydrological system, the following analysis considers what is currently defined by the United States Geological Survey as three separate river basins (the Los Angeles River, the San Gabriel River and the Santa Monica Bay) as one watershed. Geographic information about these watersheds is available through UC Davis at the California Rivers Assessment.

The first chapter of The Los Angeles River: Its Life, Death and Possible Rebirth by Blake Gumprecht (Baltimore: Johns Hopkins University Press, 1999), which is available on-line, provides a detailed description of the river landscape prior to its manipulation by urban development.

The Los Angeles River near present-day downtown, 1900

Photograph from Seaver Center for Western History Research,Natural History Museum of Los Angeles County, published in Blake Gumprecht, The Los Angeles River

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