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Warning from the Past The message, meteorology and myths from the Great West Coast

flooding of 1861- 1862

Larry SchickU.S. Army Corps of Engineers – Seattle District

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What happened in the winter of 1861-1862 ?

Historic flooding Willamette river - Oregon

Historic flooding Northern CaliforniaCentral Valley fills with water

Historic flooding Southern CaliforniaLos Angeles, Orange & San Diego County

flood

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Winter 1861-62Equivalent to 4 major hurricanes plus many

tropical storms

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What is the “Warning from the Past”?Why Care?

Framework for futureextreme floods

Prepare for possibilities

Recognize pattern California simulated major storm/flood

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What is the message?Models will forecast,

expect unexpected – details?

Series of storms – not one storm.

Dams and levees will help – and hurt

Flood risk changes as events unfoldHistory repeats itself – sort of

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A Smoking Gun ?

Major eruptionDubbi volcano – North AfricaMay 1861

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Largest historic volcanic eruptionin Africa – May 1861

Eritrea

Ethiopia

Red SeaSudan

DubbiVolcano

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Large volcanic eruptionsin the tropics cool Northern

Hemisphere

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Great Flood of 1861 - 1862Myths: confirmed or busted ?

Big Mega StormSnow melt ? Frozen ground ?Hydraulic mining debris?Central Valley Flood?Greatest Flood?

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Great Flood of 1861- 1862Myths: confirmed or busted ?

One Big Mega Storm – No

Series of storms -with a few large ones

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Great Flood of 1861 - 1862Myths: confirmed or busted ?

Snow melt caused flood - NO

greater than normal snow 500 - 3000ft deep snow higher elevationssnow melt typically: 10 – 20% of runoff

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Great Flood of 1861 - 1862Myths: confirmed or busted ?

Greatest California Flood ?

Overall storm season unprecedented

Greater high water marks than 18621805, 1825, 1850, 1852

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Hydraulic mining did it!Nope

Local runoff impacts only

1917 – USGS mining debris study –page 36

Peak debris output - 1885

1862 rainfall

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Great Flood of 1861 – 1862Myths: confirmed or busted ?

Frozen ground caused flood - NO

Cold - but not cold enough, long enough

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Great Flood of 1861 -1862Myths: confirmed or busted ?

California Central Valley: a lake – completely flooded

Yes, but not rare event

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Limited Weather Data

Pacific NW – Forts

No hourly dataConflicts of dataLimited daily data: Sacramento

San Francisco SonoraNevada City (Red Dog)

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Limited Weather Data

Southern California – no daily data, limited monthly

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Limited Weather Data

Anecdotal - newspapers, books, research, diaries

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Limited Hydro Data

Mainly USGS paleo flood or highwatermarks and estimates

No stream gauging – occasional stage observations

Anecdotal - newspapers, books, research

Peak estimates, unknown volumes

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Information sourcesInformation: recent articles & historic

documents

October 20, 1888

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1860’s Climate & Hydrology

Natural hydrologic system – limited levees & diversions

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California – Paradise Lost90% of the wetlands – gone

Wetlands: flood sponge

Then Now

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1860’s Climate & Hydrology

End of the Little Ice Age – Cool & Wet

Skating the canals – Rotterdam 1825

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1860’s Climate & Hydrology

ENSO Neutral: 1861 – 1862ENSO Neutral: West coast most extreme floods

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What is the Cause of Extreme Precipitation on the West Coast ?

Pacific storms with atmospheric rivers

Atmospheric river

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What is an atmospheric river ?

- narrow, long & moist - attach to incoming Pacific storms- cause intense rainfall & flooding

AR moisture coupled with jet stream

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Weather Pattern for Extreme Rainfall

Atmospheric Rivers 

(fall and winter)

Southwest Monsoon 

(summer & fall)

Great Plains Deep Convection

(spring and summer)

Spring  Front Range Upslope 

(rain/snow)

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The Times

Civil War in progress Lincoln president

Pony Express ends Oct 1861

Trans continental telegraph begins Oct 1861

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America 1861

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The TimesPeople lived near rivers: flat, water supply, transportation, commerce

Economy: agriculture & ranching, mining

California: 500,000 peopleOregon: 50,000 people

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Character of West Coast Winterweather of 1861-1862

Wet pattern shifted north to south

- Nov: West coast - wet and cool

- Early Dec: extreme wet Oregon

- Jan: extreme wet California

- Dec & Jan extreme cold Washington & Oregon

Persistent wet

Waves spin off main low

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November 1861Variable northwesterly storm track

Prime the pump: optimize antecedent conditions

Saturate soilsLow elevation snow High stream flows

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Fort Vancouver, Washington TerritoryDecember 2, 1861 – 7:00 am

Weather entry: 59 degreesnormally in the 30’s

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Atmospheric river arrives Oregon early Dec 1861

Similar to this -- Feb 7, 1996

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Willamette River - Oregon flood

All time record flood Willamette River, ORDec 4 1861

Commerce impacts

Likely atmospheric river

Mid/late Dec – Jan - very cold, snowy

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Willamette Valley drainage

A map

Columbia River

Willamette River

A map

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Early December 1861

Mild

Atmospheric river

Flooding

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Olympia newspaper - Dec 1861

“ the rain it raineth every day, and every night also – week in and week out, from the rising sun to the going down of same,

there is nothing but rain, rain, rain

‘The windows of heaven are opened up.’ Pluvius, grieved at some earth giving wrong, weeps as he would never dry up.”

-- Overland Press – Monday - Dec 16, 1861

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Jupiter Pluvius: street name - “sender of rain”

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Willamette FallsHistoric photo

Dec 2006 - 100,000cfs (below) Dec 1861 > 600,000 cfs at the falls

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Flat - bedded steamer St Clair

Over Willamette Falls – on purpose

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Willamette River At Salem

Dec 4, 1861

Feb 1996(if no dams)

.

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Portland, Oregon Early December 1861 flood - First and

Washington

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December 1861

BecomesVery Cold

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Northern California winter rain1861 - 1862

Note: mountains receive 2 - 4 times as much rainfall

1861-1862

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Northern California - WinterHistoric January flooding

December - Wet - 10” (San Francisco)

January - Extraordinarily wet – 24” ( S.F.)

Very wet antecedent conditions, lowland snow – Heavy rain Jan 9 -12 and 15-17

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California Rivers

Sacramento river

American river

San Joaquin river

Santa Ana river

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Atmospheric “Rex” block

Persistent rainy pattern

H

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NW in the Deep FreezeJan 1862

Seattle – below zero, 2-3 ft of snow Lake Union freezes six inches Columbia and Fraser river freeze Live stock die No communications and supplies 30 plus below zero east of the Cascades

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Mid January 1862

Atmospheric River

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January 8-12 and 15-17

1862

AR coreheavy rain

General rainfall

Flood Peak American River Jan 10th318,000 cfsSecond peak ~ 20th

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Northern California Flooding

1862

Inland Lake: 300 miles long, 20 mi wide, 20 ft deep

:Lake SacramentoJanuary 1862

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Flood Waters20-30 ft deep

Covering telegraph poles in California’s Central Valley

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Flooding In Sacramento - 1862

Legislative temporarily moved“…it appears weather ,water and whiskey had a lot to do with it”

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Sacramento Flooding 1862

“Sacramento was transformed into a sort of frontier Venice”

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American River

January 10, 1862

Regulated peaks

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Southern California Flooding 1862

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Late January Southern California 1862

Wet

Atmospheric river

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January 20-22 1862

Heavy rain Major flood

General rainfall

Heavy rainfall

Flood peakSanta Ana River – Jan 22

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Los Angeles / Orange County - 19381862 was three times as bad

Anaheim's Center Street -1938 flood

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Southern California Flooding – Jan 1862

Antecedent conditions very wetfor a month – 35” in LA

Major storm ~ Jan 20th

Santa Ana river peak January 22, 1862

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Santa Ana River

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Santa Ana River Watershed

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Santa Ana River Historic Peaks

100,000 cfs1938

317,000 cfsJan 1862

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Los Angeles County flooded areas 1862

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Aqua Mansa “calm water” – destroyed in 1862Largest settlement between New Mexico and Los Angeles

Inland Orange County -- Santa Ana river, near Colton, California

1930 flooding

“…billows 50 ft high”

late Jan 1862

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Southern California Flooding 1862

Lowland Los Angeles & Orange County

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Additional impacts

Volcano, CA landslide kills seven Colorado River –

400,000 cfs

Salton Sea fills, overflow from Colorado River

Captain of clipper “Prima Donna” logs fresh water offshore – fresh water

fish caught

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Additional impacts

Yuma, AZdestroyed

Carson Valley, NVflooding

Virgin River, UT destroys town

Ventura flooded &

abandoned

Maui, Hawaii: fir tree washes

ashore

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Cause of 1861-1862 extreme West Coast flooding

Series of storms

Intense rain: several atmospheric rivers

Optimum antecedent flood conditions:- high background river flows- saturated soils- favorable snowmelt

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Lessons of the 1861-62 Floods Models will forecast – but not detailsWet antecedent conditions - not one storm

eventDams & levees reduce flood risk – but…Changing flood risk: politics/land use/dams&

levees/climate change

History to repeat – but not exactly

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Warning from the Past Lessons from the Great West Coast

flooding of 1861 – 1862

Never underestimate the power of water

Larry SchickU.S. Army Corps of Engineers – Seattle District