a primer on the sacramento-san joaquin delta: not-so-novel ...more elephants: comparing futures for...
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A Primer on the Sacramento-San Joaquin Delta:
Not-so-Novel Problems in a Novel Ecosystem
Jeffrey Mount
Photo C. Jeffres
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
Trotting Out the Elephants
* Lead authors
More Elephants: Comparing Futures for
the Sacramento-San Joaquin Delta
Engineers:
Jay Lund, UC Davis*
William Fleenor, UC Davis
Economists:
Ellen Hanak, PPIC*
Richard Howitt, UC Davis
Biologists:
Peter Moyle, UC Davis
William Bennett, UC Davis
Geologist:
Jeffrey Mount, UC Davis
*Lead authors
Supported with funding from
Stephen D. Bechtel, Jr.
David and Lucile Packard
Foundation
Where the Wild Things Aren’t: Making the Delta a Better Place for Native Species
Peter Moyle, William Bennett, John Durand, William Fleenor,
Brian Gray, Ellen Hanak, Jay Lund, Jeffrey Mount
Funding by the S.D. Bechtel, Jr. Foundation
The Sacramento-San Joaquin Delta: Past,
Present and Uncertain Future
• Delta a landscape of
fundamental change
• Landscape evolution of
the past and future
linked to human activity
• Pace and nature of
change a significant
management challenge
Delta of the Past
• 700,000 acre tidal marsh
• Mostly fresh water, with
brackish water at western
end
• A product of Holocene
rise in sea level
• Extraordinary productivity
• Major sink for carbon
A complex, highly productive,
dynamic estuary
• Mosaic of intertidal marsh, floodplain, riparian, and tidal channels
• Very high:
– Connectivity
– Hydrologic Variability
– Physical Complexity
• Self-adjusting
Whipple et al., 2012
Transition to the 20th Century Delta
• Reclamation of 700,000 acres of tidal freshwater marsh
• 1100 miles of levees separate land from water (most of the time)
Water Supply
• Second largest ecosystem service of the Delta
• 1800 diversions
• 5- 6 MAF/year export
Keeping the Delta fresh, all the time
0
10
20
30
40
50
60
70
80
90
19301935
19401945
19501955
19601965
19701975
19801985
19901995
20002005
Delta OutflowCVP/SWP Delta exports
In-Delta diversionsUpstream
0
1
2
3
4
5
6
7
1956
1959
1962
1965
1968
1971
1974
1977
1980
1983
1986
1989
1992
1995
1998
2001
2004
2007
Mill
ion
Ac
re-F
ee
t
SWP
CVP
Delta Exports
The “New” Delta: Disconnected, Unvarying, Simplified and Novel
From Whipple et al. 2012 From Whipple et al.
2012
Ecological Regime Shift
An Ecosystem Unfriendly to Natives
The world’s most invaded
estuary?
The 20th Century Sacramento-San Joaquin Delta
Above sea level
Sea level to -10 feet
-10 feet to -15 feet
-15 feet and below
Things to Reconcile: Multiple Stressors Within and Outside of the Delta
0.00
0.50
1.00
1.50
2.00
2.50
3.00
3.50
10 11 12 1 2 3 4 5 6 7 8 9
Sacramento River
0.00
0.25
0.50
0.75
1.00
1.25
1.50
1.75
Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep
1921-2003 Unimpaired
1949-1968 Historical
1986-2005 Historical
San Joaquin River
Stressor Classes:
Flow Regime
Habitat Loss
Invasive Species
Harmful Discharges
Fisheries Management
Ocean Conditions
Things to Reconcile: There are Significant Constraints on Options
• Physical Constraints – Elevation – Tidal Energy – Space – Water availability – Salt – Temperature – Sediment
• Biological Constraints – Alien species – Habitat requirements – Endangered species – Productivity – Algae and blooms – Contaminants
Things to Reconcile: A Scientific, Management and Regulatory Adhocracy
• More than 100 agencies
and programs gathering
data
• More then 200 public
agencies with some
jurisdiction
• Parallel, not well integrated
planning and science
efforts
A simplified “conceptual model”
Things to Reconcile: Transition to the
21st Century Delta
• Sea Level Rise
• Subsidence
• Changing Inflows
• Seismicity
• Warming
• Invasions
Conclusions
Photo C. Jeffres