The Future of Water in Southern California
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30-9-2010 1 The Future of Water in Southern California Climate Change and Regional Water System Impacts Paul Bunje Executive Director UCLA Center for Climate Change Solutions Managing Director Los Angeles Regional Collaborative for Climate Action and Sustainability California’s Climate Mediterranean Climate Large influence from El Niño/La Niña and Pacific Decadal Oscillation Uneven Distribution of Precipitation Uneven Distribution of Population 240 cm/yr 2 cm/yr 140 cm/yr 60 cm/yr 35 cm/yr
Transcript of The Future of Water in Southern California
30-9-2010
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The Future of Water in
Southern California Climate Change and Regional
Water System Impacts
Paul Bunje
Executive Director
UCLA Center for Climate Change Solutions
Managing Director
Los Angeles Regional Collaborative for Climate Action and Sustainability
California’s Climate
� Mediterranean Climate
� Large influence from El
Niño/La Niña and
Pacific Decadal
Oscillation
� Uneven Distribution of
Precipitation
� Uneven Distribution of
Population
240 cm/yr
2 cm/yr
140 cm/yr
60 cm/yr
35 cm/yr
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Freshwater Consumption as a Percentage of
Local Average Annual Precipitation
USDA-NRCS, 2001
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CA Water Conveyances
CA Aqueduct:
1151 km
Sierra Snowpack
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Competing Demands
Water Uses
� Urban
� Residential
� Industrial
� Agriculture
� Environment
Impacting Factors
� Water rights
� Prior appropriation
� Population growth
� Environmental
regulation
� Climate change
California Water Supply
1998
(wet)
2000
(normal)
2001
(dry)
Total Supply (precipitation and imports) 336.9 194.7 145.5
Total uses, outflows and evaporation 331.5 208.4 159.9
Net storage change 5.5 -5.7 -14.3
Urban uses 7.8 8.9 8.6
Agricultural uses* 27.3 34.2 33.7
Environmental water† 59.4 39.4 22.5
Total dedicated Supply 94.5 82.5 64.8
Source: CA Water Plan, 2009 Update
*approx. 5 million acre-feet contributes to groundwater re-charge†9.56 million acre-feet for the Delta, 17.8 for wild and scenic river flows
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California Agriculture
� California agriculture generates approximately $36.2 billion a year, more than any other state.
� California produces more than 350 crops.
� Many are only commercially-produced in California: almonds, artichokes, dates, kiwifruit, figs, olives, persimmons, pomegranates, dried plums, raisins, clingstone peaches, pistachios, sweet rice, ladino clover seed, and walnuts.
� California grows more than half of U.S. fruits, vegetables and nuts.
� The second leading commodity, grapes, account for $2.99 billion in cash receipts annually.
� Livestock and poultry account for about 27% of California’s gross cash income, with a combined total of $10.6 billion.
� California leads the nation in milk production with over 1.8 million dairy cows, $6.92 billion in cash receipts.
California Population Growth
0
10000000
20000000
30000000
40000000
50000000
60000000
1950
1960
1970
1980
1990
2000
2010
2020
2030
2040
2050
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-100% to 41%
41% to 141%
141% to 341%
25-34 year oldPopulation Change2000-2050
Southern California Population
SCAG Region Population Trends:
Regional Share of U.S. Population
10.1
11.6
14.7
16.5
18.019.2
5
7
9
11
13
15
17
19
21
1970 1980 1990 2000 2004 2010
Millio
n
4.0%
4.5%
5.0%
5.5%
6.0%
6.5%
7.0%
Sh
are
of
U.S
. P
op
ula
tio
n
Historical 2004 RTP ShareSource: US Census Bureau, CA DOF, SCAG
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Using the Delta
Approx. 5.5 MAF
pulled out of delta
for water projects
Source: Delta Vision
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Colorado River Resources
� 7 States, 2 Nations
� Upper Basin: CO, UT, WY, NM
� Lower Basin: AZ, CA, NV
� Serves 30 million people
� Fastest Growing Part of the U.S.
� Colorado River Compact
� 1922: Approx. 19 MAF/yr
� Assumed Flow: 17.2 MAF/yr
� 60 MAF of total storage
� Irrigates 3.5 million acres
� CA receives 4.4 MAF/yrSource: US Bureau of Reclamation
Colorado River Flow
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Show CWCB slide
Changes in Temperature since 1955
Source: IPCC 2007
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Warming
Changes in Precipitation in 2100
Source: IPCC 2007
Winter Summer
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California Snow Pack
Source: CA Climate Adaptation Plan
Snow Mass Peak Date vs. April 1st SWEColored by Mean March/April Temperature
Snow Mass Peak Date (Julian Days)
Ap
ril 1
stSW
E (
cm)
Me
an
Lo
cal
Ma
rch
/Ap
ril T
em
p (
°C)
Source: Kapnick et al. 2010
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High Resolution Models Needed
Yosemite: Average March, April, May SWE at (a) 27km (b) 9km (c) 3km
Future 2km Resolution Modeling
Alex Hall et al.
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Domain of Southern California Simulation
Regional Modeling
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SoCal and the Delta
Strategies to Reduce Delta Demand
Source: California Water Plan, Update 2005
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ALTHOUGH PROBLEMS AND CATASTROPHES MAY BE INEVITABLE, SOLUTIONS ARE NOT
ISAAC ASIMOV
ALTHOUGH PROBLEMS AND CATASTROPHES MAY BE INEVITABLE, SOLUTIONS ARE NOT
ISAAC ASIMOV
