Notes on use of these slides These slides were created to accompany a presentation. They do not include full documentation of sources,
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Transcript Notes on use of these slides These slides were created to accompany a presentation. They do not include full documentation of sources,
Notes on use of these slides
These slides were created to accompany a presentation.
They do not include full documentation of sources, data
samples, methods, and interpretations.
This presentation is based on the PPIC study Envisioning
Futures for the Sacramento-San Joaquin Delta (February
2007). The full report, research brief, and related materials
are available for free download at www.ppic.org.
Questions? Contact Ellen Hanak: 415-291-4433,
[email protected].
Thank you for your interest in this work.
1
Envisioning Futures for the Delta
Engineers:
Jay Lund, UC Davis*
William Fleenor, UC Davis
Economists:
Ellen Hanak, PPIC*
Richard Howitt, UC Davis
Geologist:
Jeffrey Mount, UC Davis
Biologist:
Peter Moyle, UC Davis
* Lead authors
2
Major Themes
Current Delta is unsustainable for almost all
stakeholders
Improved understanding of the Delta provides
opportunities for new solutions
Promising alternatives exist
Most Delta users have ability to adapt
Promising solutions are unlikely to arise from a
stakeholder-only process
3
Outline
Why the Delta matters
New thinking: ecosystem and adaptation
Some long-term alternatives
Screening of alternatives
Recommendations
4
The Sacramento-San Joaquin Delta
Export
pumps
Export
pumps
5
Why the Delta Matters to Californians
Water Supply
Ecosystem
Agriculture
Infrastructure
Recreation
Housing
6
A Three-pronged Crisis
Levees at increasing risk
– Sea level rise and sinking land
– Floods and earthquakes
– Major failures end most Delta services
Steep declines in many fish species
– Many are “listed”
– Culprits: invasive species, habitat loss,
pumps
Governing institutions lacking
– Resurgence of legal actions
7
Outline
Why the Delta matters
New thinking: ecosystem and adaptation
Some long-term alternatives
Screening of alternatives
Conclusions and recommendations
8
Since 1920s, California Policy
Has Aimed to Keep the Delta Fresh
,
,
1945 USBR report
Delta farmers and water exporters benefit from low salinity
9
In 1940s, Central Valley Project Created
“Hydraulic Barrier” for Water Exports
Arrows show
movement of
fresh water
from storage
10
Historically, Delta Salinity Fluctuated
11
“Hydraulic Barrier” Limits Seasonal
and Dry-year Salinity Incursions
Dotted lines
show extent
of saltwater
incursions
Hydraulic barrier
(since 1940s)
Summers, 1908-1917
*
Summer
1841
12
Static, Freshwater Delta Not Good for
Native Species
Native species evolved in a
fluctuating Delta
Asiatic clam
Alien species have taken hold and
harm native species
Alien species do best with constant
salinity (fresh or saline)
Restoring fluctuating conditions
may be key to native species’
survival
Brazilian waterweed
Overbite clam
13
Desirable and Undesirable Species In A Salinity
Gradient With Seasonal and Annual Fluctuations
Fluctuation
High seasonal and
interannual fluctuations
Salt
Overbite clam Delta smelt
Siberian prawn Striped bass
Jellyfish
Longfin smelt
Anchovy
Splittail
Surf perches
Mysid shrimp
Marine fish
Tule perch
Fresh
Largemouth bass
Bluegill
Brazil waterweed
Water hyacinth
Asian clam
14
Adaptation Will Occur
Adaptation is unavoidable, since the current Delta
is unsustainable
All interests can adapt to some policy changes
Available tools for urban and farm sectors
– New interties, water marketing, conservation
– Conjunctive use, recycling, desalination
– Shifting crop mixes
Economic costs are finite, but can be large for
some users
15
Adaptation Potential of Delta Agriculture
to Changes in Salinity
New tool: Delta
agricultural production
model (DAP)
Currently: Low
productivity in western
and central Delta
Salinity increases would
reduce profits, but large
areas of Delta not likely
to be affected
16
Statewide Costs of Changing Delta Water
Management
Statewide integrated
engineering-optimization
model (CALVIN)
Integrates hydrology,
infrastructure,
operations, economics,
and environmental flows
Models adaptations to
changed conditions
Highlights importance of
North-South flows
17
Why We Need a New Delta Policy
Existing Delta policy is unsustainable
– All interests are getting worse together
Delta failure would be disastrous for state,
regional, and local interests
Better ecosystem understanding points to
promising new solutions
Stakeholders can better adapt to new solutions
than continue with the current high-risk policy
Promising alternatives exist
18
Outline
Why the Delta matters
New thinking: ecosystem and adaptation
Some long-term alternatives
Screening of alternatives
Recommendations
19
Nine Delta Alternatives
Freshwater Delta
– Two levee-based alternatives
– Physical salinity barrier
Fluctuating Delta
– Two peripheral canal alternatives
– Armored-island aqueduct
Reduced-exports Delta (*also fluctuating)
– Opportunistic Delta*
– Eco-Delta*
– Abandoned Delta*
20
1) Levees as Usual: Enhancing Current
Levee System, Keeping Delta Fresh
Status quo, with
improvements
Maintains current land
uses
Increasing risks of failure
Sacramento River levee
21
2) Fortress Delta: Dutch Standards of
Flood Protection – A Big Jump
Keeps Delta fresh
Strategic levees
become much more
reliable
Aids urbanization
But many islands lose
protection
22
3) Seawater Barrier: Dutch Engineers
Have Recently Revived This Solution
Prevents seawater intrusion…
…but not island flooding or other issues
Rotterdam movable storm surge barrier
23
4) Peripheral Canal Plus: Update of a
Traditional Idea
Breaks link between
exports and Delta
water quality
Allows Delta to vary
Adds ecological
management actions
Lower San Joaquin
bypass, floodplain/
marsh restoration
24
5) South Delta Restoration Aqueduct:
A New Peripheral Canal Idea
Improves South Delta
and lower San Joaquin
River water quality
Ends numerous South
Delta water quality
programs
Lower San Joaquin
flood bypass for flood
control and ecosystem
benefits
25
6) Armored-Island Aqueduct:
A Through-Delta Solution
Armor main channels,
close others to
maintain conveyance
Keeps eastern Delta
fresh
Allows western and
central Delta to
fluctuate
26
7) Opportunistic Delta:
Restores More Natural Fluctuations
Uses current export
locations, pumping is
opportunistic
Western and central
Delta salinity
fluctuates
Water exports lower
and more variable
Adds near-pump
storage
27
8) Eco-Delta: An Example of
Local Specialization
Allows opportunistic
pumping, but at
lower levels
Promotes fluctuating
western Delta
Specialized
restoration of
islands, bypasses
28
9) Abandoned Delta: Letting Nature Take
its Course
Abandon an unreliable
resource
2-in-3 probability of
abrupt change from
earthquake or flooding
End of water exports
End of ecosystem
investments
29
Outline
Why the Delta matters
New thinking: ecosystem and adaptation
Some long-term alternatives
Screening of alternatives
Recommendations
30
Screening Criteria
Ecosystem performance (conceptual model)
Water exports (CALVIN)
Economic and financial costs
– Delta agriculture and salinity (DAP)
– Costs of export adaptations (CALVIN)
– Investment costs (existing studies)
Other Delta services (qualitative)
31
Fluctuating Delta Alternatives
Are Most Promising
Alternatives
Environmental
Performance
Annual Water
Exports
Economic and
Financial Costs
1. Levees as Usual
Poor
0 – 6+ maf
~$2 Billion +
failures
2. Fortress Delta
Poor
> $4 Billion +
lost islands
3. Saltwater Barrier
Poor
$2 – 3 Billion +
lost islands
6+ maf
4. Peripheral Canal Plus
5. South Delta Aqueduct
6. Armored-Island
Aqueduct
Promising allows Delta to
fluctuate
$2 – 3 Billion +
< $70 M/year
Mixed
$1 – 2 Billion +
< $30 M/year
$2 – 3 Billion +
< $41 M/year
Promising
2 – 8 maf
$0.7 – 2.2 Billion +
< $170 M/year
8. Eco-Delta
Best?
1 – 5 maf
Several $ Billion +
< $600 M/year
9. Abandoned Delta
Poor
0
$500 Million +
~$1.2 Billion/year
7. Opportunistic Delta
32
Outline
Why the Delta matters
New thinking: ecosystem and adaptation
Some long-term alternatives
Screening of alternatives
Recommendations
33
“No Regrets” Short-term Actions
Emergency preparedness
“Do not resuscitate” list for some islands
Delta land use
– Flood control guidelines for urbanization
– Habitat protection
Suisun Marsh and Cache Slough projects for
pelagic fish
34
Steps Needed for a Long-term Solution
Focus on promising alternatives
Create technical track to explore solutions with
problem-solving R&D
Enhance regional and statewide representation
in Delta land use decisions (e.g. SF BCDC)
Implement “beneficiaries pay” financing
Establish mitigation mechanisms – everyone will
not “get better together”
35
Begin a Delta Solutions Program
Solution-oriented scientific and technical program
Relatively quick study examples
– Biological habitat objectives
– Hydrodynamics of salinity fluctuation
– Institutions for guarantees and beneficiary pays
– Island economics and risks
– Water operations and economics
Technical support to policy process
36
Postscript: Reactions to the Report
Governor’s Delta Vision Blue Ribbon
Committee announced same day as release
SB 27 (Simitian’s peripheral canal bill)
amended
– Broadened to our 5 promising alternatives
– Now co-authored by 3 other senators
Shift in the Delta policy debates
– OK to talk about ideas that were off the
table in CALFED era
37
New Delta Solutions
Will Require Public Buy-In
> 90 % “no”
70 – 90 % “no”
50 – 60 % “no”
50 – 60 % “yes”
> 60 % “yes”
County voting patterns
for Proposition 9
(Peripheral Canal)
June 1982
38
Questions?
Full report, research brief, and other materials at:
www.ppic.org and watershed.ucdavis.edu
Dutch North Sea Levee
Fortress Delta
Abandoned Delta
Eco-Delta
39