Adapting Water Management to Climate Change Some Ideas ...€¦ · Adapting Water Management to...
Transcript of Adapting Water Management to Climate Change Some Ideas ...€¦ · Adapting Water Management to...
Adapting Water Management to Climate Change
– Some Ideas from California
Jay R. Lund
Department of Civil and Environmental Engineering
University of California - Davis
“You can never step in the same river twice”
Heraclitus
CaliforniaWaterBlog.com
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Main points1. California has a dynamic global society, economy, &
climate – Mostly good, but challenging.
2. Economic structure drives most management change
3. Water management portfolios are central to success – supplies and demands, with others in region
4. Portfolios add flexibility for variability & uncertainty
5. Droughts/crises provide focus to help water adjust management to changing objectives and conditions
6. Technological and institutional adjustments build on existing institutions and infrastructure
7. Adjustments also rebalance portfolio of local, regional, state, and federal roles and innovations
Water and People in California
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18 million people756,000 sq. km.
40 million people404,000 sq. km.
California has lots of droughts
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SOURCE: Western Regional Climate Center.
Most annual rainfall variability in US
SOURCE: Dettinger, et al. 2011. “Atmospheric Rivers, Floods and the Water Resources of California.” Water 3(2), 445-478. .
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
Major Climate Changes
1) Sea level rise
2) Warmer temperatures – less snowpack
3) Bigger flood and drought extremes
4) Other changes …
5) Similar overall precipitation for
California?
Other Major Changes?
1) Population and economic growth
2) Less per-capita water use
3) More tree & vine crops, less irrigated area
4) More environmental water demands
5) Other changes …
Must manage for all these changes, and more…
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Each drought hits a different economy
Droughts
• Paleo-droughts
• 1800s
• 1924
• 1928-32
• 1976-77
• 1988-92
• 2007-09
• 2012-16
Economy
• Pre-European
• Range cattle
• Early farming
• More farming
• Farms + cities
• Farms, cities, environment
California’s economy less agricultural – more robust to drought
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Droughts and change in California 1
Drought Impacts Innovations
1800s Herds & crops
devastated
Local irrigation, 1873
fed CV study
1924 crop
devastation
Local res. projects,
Major water project
plans – regional/state
1928-32 Delta salinity,
crop losses
Major dam & canal
project plans –
statewide scale
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Droughts and change in California 2
Drought Impacts Innovations
1976-77 Big brief urban & ag.
shortages
Urban cons.;
early markets
1988-92 Urban & ag. shortages
Endangered fish
Interties, conj.
use; markets,
cons., regions
2007-09 Agric. & fish supplies More use data;
Delta, urb.cons.
2012-16 Warm drought, little
Delta water, big agric.
shortages, fish, forests
Groundwater,
Delta barrier,
more reporting
Actions
Local, private
Local, public + private - diversions
Regional, statewide- dams, canals
Local urban conservation, trades
Interties, conj. use, water markets, new storage – regional, local
More data, Delta institutions
Groundwater – local region w/ state; urban cons. Mandates; fires?
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Swinging Portfolio Development: Institutions and Technology
Droughts
• 1800s
• 1924
• 1928-32
• 1976-77
• 1988-92
• 2007-09
• 2012-16
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2012-2016 DroughtFrequency – warm drought!
Soil moisture – 1 in 1,200 year event?
Snowpack – 1 in 500 year event
Water availability – 1 in 15-40 year event
Damages
Imperceptible statewide urban damage
2-3% loss of agricultural revenues
Forests much affected; fish stocks depleted
Droughts help us make needed changes!
System Integration
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• California’s water system is more than just storage and conveyance
• Portfolio management is successful, but takes time and organized effort.
• Extensive, diverse, variable, & network encourages portfoliomanagement – “much of the above”
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What is Portfolio Management?1. Integrated use of a diverse range of actions:
• Supplies (surface water, groundwater, reuse)• Demands (various)• Institutions (local, regional, state, federal)
2. Lower costs, more adaptable, better multi-benefit performance
3. Adjust with time, conditions, technology, and problems
4. Integration needs more analytical and management effort
5. Adjustments rebalance local, regional, state, and federal actions over time – adaptive management
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Portfolio ElementsMultiple-barriers Infrastructure Multiple Accountability
1. Banned/regulated chemicals and
activities
Local water utility, elected
boards
2. Source protection: Rivers, lakes,
reservoirs, groundwaterPublic health agencies
3. Drinking water treatment State regulators
4. Distribution system Federal regulators
5. Public health system Professional societies
Universities, NGOs, media
Multiple barrier portfolios for waterborne diseases
What would portfolios look like for ecosystem management?
Managing portfolios across sectors?
Portfolio are Local, Regional, & StatewideLocal Activities:- Conservation and use efficiency- Wastewater reuse- Desalination (brackish & ocean)- Groundwater use and recharge- Surface reservoir operations- Water markets and exchanges
Statewide Activities:- Inter-regional water conveyance- Surface reservoir operations- Plumbing codes & conservation incentives- Groundwater banking and recharge- Water market support and conveyance - Wastewater reuse subsidies
Integrating mix of actions and agreements = portfolio planning 17
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San Diego water supply portfolio588 taf/yr578 taf/yr
477 taf/yr694 taf/yr
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Agricultural water supply portfolio –Tulare Basin, California
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
0 2000 4000 6000 8000 10000Cumulative Irrigated Crop Area (1,000 Acres)
Cumulative Jobs and Revenues
Cumulative Jobs
Vegetab
les,
Vin
es
Sub
trop
ical Fruits
Alm
on
ds an
d P
istachio
s
Decid
uo
us
(Orch
ards)
Pro
cessing
Tom
ato
Other Field, Grain, and Feed Crops
Fresh To
mato
+ Cu
curb
its
On
ion
+ Garlic
Josue Medellin
2015 Estimated Agricultural Drought Impacts
Description Impact Base year Percent
Drought water shortage (million acre-ft) 8.7 26.4 33%
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 9 million* 6%
Crop revenue losses ($) $900 million $40 billion 2.3%
Dairy and livestock revenue losses ($) $350 million $13 billion 2.7%
Costs of additional pumping ($) $590 million $780 million 75.5%
Net revenue losses ($) $1.8 billion 54 billion rev. 3.3%
Total economic impact ($) $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 is 1.2 million acres.
# Total agriculture employment is about 412,000, of which 200,000 is farm production.
Analysis and data for integration
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• Integrating complex systems• Complexity of portfolios• Institutional integration• Conflicting institutional missions• Often easier from local level up• Adapt portfolios over time
•Analysis and data helps• Models (integrated, hydro-economic)• Databases• Access, quality control, transparency
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Agricultural water supply portfolio
Pros and Cons of Portfolios
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• Pros• Lower cost mix of actions• Make more friends, more resource access• More adaptable and flexible• Higher reliability
• Cons• Harder to manage• Messier negotiations• Harder to regulate• Need to adapt portfolios over time
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Complexity adds possibilities1) Portfolios central to success for many
water purposes and problems
2) Overall economy is robust to well-managed water. But ecosystems most harmed/least prepared
3) Integration is easier said than done
4) Integration needs organization,
incentives, state framework
5) Better water accounting
6) Change will occur, must
prepare for it
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Some lessons from California
1. Portfolio-based management can be cost-effective and adaptable
2. Portfolios manage supplies, demands, and finance together, regionally.
3. More expensive supplies encourage managing demands and integrated management.
4. Globalization buffers against drought
5. Each drought is different, but all give opportunities
6. Economic structure drives/supports management
7. Climate and other changes will require careful changes to management.
Further Readings Lund et al. (2018) , "Lessons from California's 2012-2016 Drought," JWRPM, Oct. 2018
Hanak et al. (2011) Managing California’s 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
Pinter, et al. (in press), “The California water model: Resilience through failure,” Hydrologic Processes.
Pisani (1983), From Family Farms to Agribusiness, UC Press
Mavensnotebook.com
CaliforniaWaterBlog.com