Progress on Incorporating

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Progress on Incorporating Climate Change into
Management of Californias Water Resources
CA DWR, July 2006
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California As Leader
As of today, California is going to be a leader
in the fight against global warming ... the
debate is over. We know the science. We see the
threat. And we know the time for action is
now. Gov. Arnold Schwarzenegger, UN World
Environment Day, San Francisco, June 2005.
Executive Order S-3-05
2010 Reduce Emissions to 2000 Levels 2020
Reduce Emissions to 1990 Levels 2050 Reduce
Emissions to 80 below
1990 Levels
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Overview of Californias Water Resources
Surface Water Storage and Conveyance Works
1. Surface Water

• Two large water projects (SWP/CVP) supply
  water to nearly 20 million residents in
  southern CA
• Distribution of Precipitation vs. Population
  gt 140 of precip in Northern CA with lt 4
  in Southern CA annually, on avg. ½ of the
  population lives in Southern CA Significant
  agriculture in San Joaquin and Imperial
  Valleys.
• Capacity of 29 million ac-ft in CV reservoirs
  (avg. ann. runoff in CV 33 million ac-ft)
• SWP/CVP provide 10 million ac-ft annually for
  urban and agricultural use
• Additional low flow requirements for water
  quality and ecological purposes

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Overview of Californias Water Resources
2. Colorado River Water

• Largest source outside of CV
• 1922 Colorado River Pack divided into
  upper/lower basins Each basin apportioned 7.5
  million ac-ft
• 1944 Treaty guarantees 1.5 million ac-ft to
  Mexico
• 1964 Supreme Court defines Lower basin
  allocation California 4.4 mill
  ac-ft Arizona 2.8 mill ac-ft
  Nevada 0.3 mill ac-ft

• Two aqueducts supply water to Coachella and
  Imperial Valleys, and MWD
• In recent years, diversions of up to 5.3 mill
  ac-ft annually to California

3. Ground Water

• Contributes 30 of the urban and agricultural
  demand

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Overview of Californias Water Resources
CA DWR
US Bureau of Reclamation
CALIFORNIA WATERRESOURCES
CALFED Bay-Delta Program
US Army Corps of Engineers
US Geological Survey
California Energy Commission
Other State/Local Agencies
Other Non-Governmental Agencies
CalEPA
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State Water Management CA DWR
Clearly recognize the importance of considering
climate change in future water resources
planning toward meeting the state objectives
Provide sufficient water supply Drought
preparedness Improve water quality Reduce flood
impacts Reduce GW overdraft Providing energy,
environmental, and recreational benefits Improve
operational flexibility and efficiency
Future WR management under climate change may be
different due to variability and extremes
outside those under which current system
was designed current systems assumes there
is time to react to climate changes
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State Water Management CA DWR
2005 Water Plan Update Outlines 25 Management
Strategies
Projected cost (thru 2030), Billion

• Reduce Water Demand agricultural water use
  efficiency 0.3-4.0 urban water use efficiency
  2.5-6.0
• Increase water supply conjunctive management/GW
  storage 1.5-5.0 desalination 0.2-1.6
  recycled municipal water 6.0-9.0 increase
  surface storage 0.2-5.6
• Improve water quality drinking water treatment
  distrib 17.0-20.0 GW Remediation 20.0
  pollution prevention 15.0
• Resource Stewardship ecosystem restoration
  7.5-11.3

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Surface Storage

• Objective to increase water supply and provide
  increased operational flexibility to current,
  highly constrained system

Potential locations currently being investigated
at State level (CALFED) Three locally developed
reservoirs Los Vaqueros (Northern)
Olivenhain (Southern) Diamond Valley
(Southern) Supply augmentation of up to 400,000
ac-ft for an individual reservoir Costs - 65
million to complete investigations
180 million 2.4 billion in capital costs for
each project Ongoing maintenance and
operating costs
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Recycled Municipal Water

• Objective to augment existing water supply

Currently, 500,000 ac-ft is recycled annually by
agencies Potential of 0.9 1.4 million ac-ft of
additional water supply Additional benefits
Soil conditioning and reduction in fertilizer
use Reduction in pollutant discharge
Increase security of source during
drought/dry Potential energy savings over
(energy intensive) imported
water Drawbacks Costs - 6-9 billion
estimated through 2030 Public perception
(toilet to tap) Potential water quality
issues Heavy metals Salt Microbiological Emergin
g contaminants Downstream
impacts/maintaining low flows
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Urban Water Use Efficiency

• Objective to lower water demand and extend
  water supply

Once used as temporary response in drought or
emergency storage conditions, use efficiency
conservation becoming viable long-term approach
for water supply
Water supply savings 0.8 million ac-ft
for existing efforts, with additional savings up
to 2.3 million ac-ft with technological advances
Dry coolingfor power plants
Hot-water -on-demand systems
Issues Costs highly dependent on local
investment Effective and equitable funding
opportunities Lack of baseline data to
assess effectiveness Public education
Efficient appliances
Low Flow toilets
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Implementation Example INFORM

• Objective Increase efficiency of water use
  management through use of
  climate, hydrologic and decision science

INFORM Integrated Forecast and Reservoir
Management
TRINITY
SHASTA
OROVILLE
NEW BULLARDS
FOLSOM
A real-time, operational hydrologic
forecast-decision support system for the
integrated management of five large reservoirs
in Northern California. A virtual system
developed and implemented through Winter 2006
season in collaboration with NWS, DWR, BoR,
USACE, and others.
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INFORM SCHEMATIC
CLIMATE MODELS
PRECIP TEMPERATURE FORECASTS (ENSEMBLES)
CONSTRAINTS PROCEDURES
DOWNSCALING MODELS
GOALS Water Supply Flood Control Hydro-Power Envir
n. Flows Delta Salinity
RAIN-SNOW-SNOWMELT
HYDROLOGIC MODELS
PROBABILISTIC RESERVOIR INFLOW FORECASTS
RESERVOIR MODEL DOWNSTREAM SYSTEM
OPTIMIZATION
FEASIBLE POLICIES TRADE-OFFS
DWR, BoR, USACE, CNRFC
DECISION SUPPORT
RELEASE DECISION MANAGEMENT ASSESSMENT
Recommendation Use of modern probabilistic
weather hydrological forecasts for the
management of water reservoirs and other
resources in the State (Climate Action Team, 2006)
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Summary

• State water managers recognize significant
  potential climate change impacts on
  California water resources
• Water plan outlines multiple potential
  strategies to meet management objectives
  under uncertain future
• Water use efficiency and recycling offer
  potentially greater benefits
• Increased implementation of strategies, science,
  and technology is needed

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Current No-Regret Actions

• Re-evaluate procedures for water resources
  management in light of climate change impacts
  that are highly likely
• Encourage flexible institutions for water
  allocation (e.g., markets)
• Plan on basis on hydrologic boundaries (not
  political)
• Explore opportunities for conservation, demand
  management efficiency
• Support interdisciplinary research on broad
  impacts
• Update and improve water laws and legal
  allocations
• Invest in multi-benefit efforts
• Improve forecasting for climate, weather, and
  flood

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Resources
DWR, 2006 Progress on Incorporating Climate
Change into Management of Californias Water
Resources, Technical Memorandum Report,
California Dept. of Water Resources, Sacramento,
CA, July 2006, 339 pp. Available via
http//baydeltaoffice.water.ca.gov/climatechange.c
fm DWR, 2005 California Water Plan Update 2005,
Volume 2 Resource Management Strategies, Departm
ent of Water Resources, State of
California,December 2005 Available via
http//www.waterplan.water.ca.gov/strategies/index
.cfm Kiparsky, M., P.H. Gleick, Climate
Change and California Water Resources A Survey
and Summary of Literature, California Water Plan
Update 2005, Volume 4 Reference Guide,
Department of Water Resources,State of
California, 2005. Available via
http//www.waterplan.water.ca.gov/climate/index.cf
m Climate Action Team, 2006 Climate Action Team
Report, California EPA, March 2006, 12xx pp.
Available via http//www.climatechange.ca.gov/ C
alifornia Climate Change Center, 2006 Our
Changing Climate - Assessing the Risks to
California, Summary Report CEC-500-2006-077,
California Energy Commission and CalEPA, July
2006, 16 pp. Available via http//www.climatechang
e.ca.gov/ Georgakakos, K.P., Graham, N.E.,
Carpenter, T.M., Georgakakos, A.P., and H. Yao,
2005 Integrating Climate-Hydrology Forecasts
and Multi-Objective Reservoir Management for
Northern California, EOS, 86(12), 22 March 2005,
pp. 122, 127.
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Food For Thought
NOW is the time to identify paths to CA future ...

• Identify feasible and non-feasible paths
• Avoid crisis points irreversible paths
• Must address urban population growth vs.
  agricultural growth