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