Oct 19, 1999 · Deadly Flood of 1938 Left Its Mark on Southland. ... All anyone knew was that a relentless flurry of rainstorms kept drenching Southern California.
Los Angeles flood of 1938
From Wikipedia, the free encyclopedia
Los Angeles Flood of 1938
The Los Angeles River overflowing its banks near Victory Boulevard
|
| Date |
February–March 1938 |
| Location |
Los Angeles, Orange, Riverside, San Bernardino and Ventura counties, California |
| Deaths |
113-115 |
| Property damage |
About US$40 million ($627 million in 2011 dollars)
5,601 buildings destroyed
1,500 buildings damaged
several small towns completely destroyed
Large portions of Riverside and Orange counties completely inundated |
The
Los Angeles flood of 1938 was responsible for inundating much of
Los Angeles,
Orange, and
Riverside counties,
California during February and March 1938. The flood was caused by a pair of Pacific storms that swept inland across the
Los Angeles Basin, causing abnormally high rainfall across much of coastal Southern California. Between 113
[1]
to 115 people were killed in what ultimately became one of the most
catastrophic natural disasters in Southern California history.
[2] The flood caused the
Santa Ana,
Los Angeles, and
San Gabriel
Rivers to burst their banks, washing away roads, bridges, and
buildings, and stranding hundreds of people. Damages in parts of Los
Angeles County were moderated by dams in the
San Gabriel Mountains, while Orange and Riverside Counties took more damage because of the lack of flood-control works in the Santa Ana River system.
[2]
The flooding event of 1938 is considered a
50-year flood.
[citation needed] It resulted in $40 million of damages, and the
Red Cross deemed it the "fifth largest flood in history".
[1] In response to the floods, the
U.S. Army Corps of Engineers began
channelizing local streams and building more flood control dams. Dams built in the aftermath of the flood include
Sepulveda Dam,
Hansen Dam,
Prado Dam, and
Whittier Narrows Dam, which hydrologically connects the
San Gabriel River to the
Rio Hondo.
These works have been instrumental in protecting coastal Southern
California from subsequent flooding events, although the storms of 1969
and
2005, which had larger volume than the 1938 flood, still caused major damage and forced the evacuation of low-lying areas.
[1]
Background
This well constructed section of the Los Angeles River channel was one
of the few sections of riverbank that withstood the 1938 flood.
Between February 27 and 28, 1938, a storm from the
Pacific Ocean moved inland into the Los Angeles Basin, running eastward into the
San Gabriel Mountains.
The area received almost constant rain totaling 4.4 in (110 mm) from
February 27-March 1. This caused minor flooding that affected only a few
buildings in isolated canyons and some low-lying areas along rivers.
[2]
Fifteen hours later on March 1, at approximately 8:45 PM, a second
storm hit the area, creating gale-force winds along the coast and
pouring down even more rain. The storm brought rainfall totals to 10 in
(250 mm) in the lowlands and upwards of 32 in (810 mm) in the mountains.
[3] When the storm ended on March 3, the resulting damage was huge.
[2]
Flooding effects
Overall, the flood of 1938 destroyed 5,601 buildings, damaging a further 1,500, and stranded over 800 cars.
[2]
The floods carried large amounts of debris and sediment down from the
mountains, burying roads and stopping traffic for many days. The general
hospital of Los Angeles County was threatened by rising floodwaters,
which had inundated the backup power generator.
[4] More than 20 structures were destroyed in the
Arroyo Seco canyon, but there were no fatalities there.
[5]
Large swathes of concrete channel at the
Tujunga Wash were decimated by the flood.
Damage was probably most severe along the
Santa Ana River
in San Bernardino, Riverside and Orange Counties further south. Without
any flood control dams, the river swelled to over 317,000 cu ft/s
(9,000 m
3/s), almost half the flow of the
Mississippi River.
The flooding was so intense that it transformed most of low-lying
northwestern Riverside County and northern Orange County into a large
lake. The town of Agua Mansa in Riverside County, with a population of
over 200, was completely swept away. The cities of Anaheim and Santa
Ana, further downstream in Orange County, were covered with up to 6 feet
(1.8 m) of water.
The
Los Angeles River reached a maximum flood stage of 130,000 cu ft/s (3,700 m
3/s). The
Tujunga Wash reached its peak flow on March 3, with a water flow of an estimated 50,000 cu ft/s (1,400 m
3/s), after the
Big Tujunga Dam
had begun emergency spillway releases. In the San Fernando Valley, the
floodwaters swept through many areas after escaping their normal
channels of Tujunga Creek and its tributaries. Waters reached deep into
the valley and flooded portions of
Van Nuys and
Lankershim Boulevard. This extensive flooding brought about the building of
Hansen Dam.
[5]
The
San Gabriel River reached a peak of 150,000 cu ft/s (4,200 m
3/s) at the confluence of the East and West Forks. The water swept into the reservoir of the nearly completed
San Gabriel Dam, filling it to capacity. Dam operators held releases to a maximum of 90,000 cu ft/s (2,500 m
3/s), while further downstream
Morris Dam was able to reduce the flood to 65,700 cu ft/s (1,860 m
3/s). As a results, large areas of the
San Gabriel Valley were spared from flooding, although damages still occurred locally on smaller streams that drain out of the mountains.
[2]
Although most of the damage occurred on the windward (western) side
of the San Gabriel Mountains, large amounts of rain also fell on the
east side which drains to the
Mojave Desert. The
Little Rock Dam on
Little Rock Creek
overtopped during the flood due to a damaged spillway siphon that had
been plugged by debris swept downstream, while another dam in Pickens
Canyon produced such large flood releases that it inundated the
Roosevelt district of
Lancaster.
Aftermath
Aftermath of the flood in Anaheim, Orange County
Receding floodwaters downstream of Barham Blvd.
Many people were marooned in the San Gabriel Mountains following the
storms, as severe mudslides and flooding prevented their escape. It was
said that all roads leading into the mountains had been washed out in
some way and notably, Big Tujunga Canyon was "all but swept clean of
structures that were not up above the flood line".
[5]
Dams such as the San Gabriel River dams and one on Big Tujunga Creek
greatly reduced the flooding in many areas. It was said that "Were it
not for the Big Tujunga Dam, which finally filled to capacity and began
spilling, the flood on the Los Angeles River would have been much worse
than it already was."
[6]
Los Angeles County was not the most affected by the floods; Riverside
and Orange "took the brunt of the waters" like "gargantuan saucers".
(Los Angeles Times, 1938.) At the time, Los Angeles county was the most
populous of the three; Orange and Riverside were mostly farming and
ranching regions. Therefore, many people were spared by the distribution
of floodwaters.
[2]
Media and news attention
The
Los Angeles Times chartered a
United Air Lines
Mainliner to provide them an aerial view of flooding damage. The
reporter was said to comment that "Disaster, gutted farmlands, ruined
roads, shattered communications, wrecked railroad lines—all leap into
sharp-etched reality from that altitude." The Los Angeles River also was
not the most affected watershed; the Santa Ana River, at twice its
length, was famously commented on as being "swollen crazy-mad".
[7]
See also
References
California portal
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