Drought and California€¦ · 2/6/2016 · 1) 4th year of drought, so far similar to droughts...
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Jay Lund Director, Center for Watershed Sciences Professor, Civil and Environmental Engineering University of California, Davis CaliforniaWaterBlog.com Drought and California
Transcript of Drought and California€¦ · 2/6/2016 · 1) 4th year of drought, so far similar to droughts...
Jay Lund Director, Center for Watershed Sciences
Professor, Civil and Environmental Engineering
University of California, Davis
CaliforniaWaterBlog.com
Drought and California
What people know…
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Main Points 1) 4th year of drought, so far similar to
droughts seen 1-2 times per generation
2) California is doing amazingly well, given the magnitude of the drought
3) Stay between complacency and panic 4) Integrated portfolios are the future
5) High value crop production should be less affected
6) Droughts and floods remind us to change, and prepare.
Water and People in California
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Most annual rainfall variability in US
SOURCE: Michael Dettinger, 2011. “Climate Change, Atmospheric Rivers, and Floods in California—A Multimodel Analysis of Storm Frequency and Magnitude Changes.” Journal of the American Water Resources Association 47(3):514-523.!
NOTES: Dots represent the coefficient of variation of total annual precipitation at weather stations for 1951-2008, Larger values have greater year-to-year variability. !
Annual coefficient of variation!
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Drought in California 1) Large agricultural water
use (80% of human use) - 9 million irrigated acres, $45 billion/yr
2) $2 trillion economy 3) Native ecosystems – fish
and birds 4) Major changes in
habitats, flows, species 5) Droughts lead to change
1. Water needs are always changing
2. Major water policy changes require droughts, floods, or lawsuits – benefits of drought
3. Every generation requires a threatening flood and a threatening drought – We’ve got one.
Droughts test, and spur progress
Sacramento Valley Precipitation
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2014: !8th
driest in 106 years!
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San Joaquin Valley Precipitation
2015: !3rd
driest in 106 years!
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Sierra Snowpack
A warm drought!!
Lowest snowpack on
record!
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Reservoir levels
2015 Water Shortage & Changes in Groundwater!
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Region
2015 Water use changes (MAF) Surface Water
Groundwater
Net Delivery Shortage
Sacramento -2.29 1.19 -1.1 San Joaquin -1.84 1.40 -0.44 Tulare -4.57 3.41 -1.16 Central Coast and So. Cal.
-0.02 0.02 0.01
Total -8.72 6.02 -2.7
2015 Estimated Agricultural Drought Impacts!
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Description Impact Base year levels
Percent change
Surface water shortage (million acre-ft) 8.7 18.0 -48%
Groundwater replacement (million acre-ft) 6.0 8.4 72%
Net water shortage (million acre-ft) 2.7 26.4 -10%
Drought-related idle land (acres) 540,000 1.2 million* 45%
Crop revenue losses ($) $900 million $35 billion 2.6%
Dairy and livestock revenue losses ($) $350 million $12.4 billion 2.8%
Costs of additional pumping ($) $590 million $780 million 75.5%
Direct costs ($) $1.8 billion NA NA
Total economic impact ($) $2.7 billion NA NA
Direct job losses (farm seasonal) 10,100 200,000# 5.1%
Total job losses 21,000 NA NA
* NASA-ARC estimate of normal Central Valley idle land. # Total agriculture employment is about 412,000, of which 200,000 is farm production.
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100%!
0! 2000! 4000! 6000! 8000! 10000!Cumulative Irrigated Crop Area (Acres)!
Cumulative Jobs and Revenues!
Cumulative Jobs!
Cumulative Revenues!
Vegetables,! H
orticulture & Non-Tree Fruits!
Vines!
Subtropical Fruits!
Almonds and Pistachios!
Deciduous (O
rchards)!
Processing Tomato!
Other Field, Grain, and Feed Crops!
Fresh Tomato + C
ucurbits!
Onion + G
arlic!
Cities and suburbs
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• So far… • Investments paid off • Regional cooperation • Conservation working
• Continued drought… • Supplies more constrained • Pricing restrictions (Prop 218)
and affordability issues • Some challenges with
conservation mandate • But economic impacts likely to
remain small
Rural communities
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• So far… • 2,000+ dry domestic
wells, 100+ small systems in trouble
• Strong emergency response
• But time lags still too long
• Continued drought… • Increase in dry wells • Worsening air quality • Economic hardship
Ecosystem and drought
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• 18 fish at risk of extinction • Need strategic flows,
conservation hatcheries • High waterbird mortality
• Need for strategic wetland watering
• Severe wildfire risk, with some permanent losses of conifer forests
• Little drought preparation
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- Limited supply - Local & regional demands - Flood storage - Fish
Folsom Water Storage
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American R. Basin Supplies
From: Mavensnotebook.com
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Drought Sac Metro Area
1) Cities hit by Folsom and Governor’s orders 2) Shallow domestic wells 3) Native ecosystems – fish and birds 4) Lost hydropower 5) Farming not too badly affected 6) Lost recreational skiing and rafting
Surprise! Sacramento Area is vulnerable to drought!
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What to do?
1) Intertie urban surface supplies 2) Better manage groundwater 3) Reduce long-term water use 4) Improve environmental management 5) Prepare for less snow!
Portfolio-based Management Supply
• Reoperation • Reservoirs • Conveyance
• Conjunctive use • Expand conveyance & storage • Urban reuse • New water treatment
• Wastewater reuse • Ocean Desalination • Contaminated aquifers
• Stormwater capture • Source protection! 22!
Demand and Allocation • Agricultural water use
efficiencies and reductions • Urban water use efficiencies
and reductions • Ecosystem demand
management • Recreation water use
efficiencies
Incentive policies • Pricing • Markets • Subsidies, taxes • Education
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Innovations from this drought? 1. Groundwater management 2. Better water accounting 3. Better water markets 4. Lower targets for urban water use – ripple
effects for conservation, finance, planning 5. Higher agricultural water prices – and less
agricultural water use 6. Better state agency coordination? 7. Others?
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Droughts test water systems!
1. Water systems and the societies they serve are always changing.
2. Droughts bring attention to needs for change 3. This drought is helping California improve
water management - groundwater 4. Every generation needs at least a
threatening drought, and a threatening flood
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Conclusions 1) 4th year of drought, so far similar to
droughts seen 1-2 times per generation
2) California is doing amazingly well, given the magnitude of the drought
3) Stay between complacency and panic 4) Integrated portfolios are the future
5) Sacramento region is vulnerable to drought
6) Droughts and floods remind us to change, and prepare.
Suggested Readings
Hanak et al. (2011) Managing California’s Water, PPIC.org
Hanak et al. (2010) Myths of California Water, PPIC.org
Hundley (1992), The Great Thirst, UC Press.
Kelley (1989), Battling the Inland Sea, UC Press.
Lund et al. (2010) Comparing Futures for the Sacramento San Joaquin Delta, UC Press
Pisani (1983), From Family Farms to Agribusiness, UC Press
Mavensnotebook.com
CaliforniaWaterBlog.com
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Will next year be dry? (from historical data, 1906-2013)
Probability next yearSacramento Valley San Joaquin Valley
Next Year Historical Critical now Historical Critical nowCritical 0.13 0.29 0.18 0.55Dry 0.21 0.35 0.14 0Below Normal 0.18 0.07 0.16 0.15C,D 0.34 0.64 0.32 0.55C,D, BN 0.52 0.71 0.48 0.7AN, W 0.48 0.29 0.52 0.3
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Streamflow and El Nino
ENSO Index!
Sac.
Riv
er A
nnua
l Run
off,
maf!
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El Nino and drought
ENSO Index!
Annu
al R
unof
f, m
af!
Resistance is Futile 1) Flooding in parts of the Delta 2) Reduced Delta diversions 3) Less irrigated land in the southern Central Valley 4) Less urban water use, more reuse & storm capture 5) Some native species unsustainable in the wild 6) Funding solutions mostly local and regional 7) State’s leverage is mostly regulatory, not funding 8) Nitrate groundwater contamination is inevitable 9) Groundwater will be managed more tightly 10) The Salton Sink will be largely restored We cannot drought-proof, but we can manage better.
