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Higher and Hotter Water: Climate Change and the

Sacramento-San Joaquin Delta

Jay R. Lund, Director

Center for Watershed Sciences, University of California, Davis

CaliforniaWaterBlog.com

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Sacramento Valley -4+ maf taken upstream

Delta farmers – 1+ maf

Bay Area – 30% directly, another 40% upstream

S. Central Valley – 4 mafdirectly; 4 maf upstream

S. California – 30% of supplies

Many want more …

The Delta

Everybody takes Delta water

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Sacramento-San Joaquin Delta Overview

1. The Delta was built by sea level rise

2. Agriculture, recreation, and cities are the

economy

3. Much of the western and central Delta is

subsiding

4. Supplies water for much of California

5. Home to many “listed” native species

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SF Estuary & Delta Wetlands: 1848 and today

http://sfbay.wr.usgs.gov/access/yearbook.html

Delta, 1905

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Delta Island Subsidence

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

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Threats to Delta Water and Ecosystems

Physical instability– Land subsidence

– Sea level rise

– Floods

– Earthquakes

– Ships, etc.

Ecosystem instability – Habitat alteration

– Invasive species

Economic instability– High costs to repair islands

– Worsening water quality

– Growing overall water scarcity

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Climate Impacts

1. Sea level rise (1-3+ ft/century)

2. Higher temperatures

3. Seasonal shifts in inflows

4. More extreme floods and droughts

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Policy Decisions for the Delta

Levees

– Which islands to support?

– Who pays?

Ecosystem management

– Manage for what?

– Where and how?

– With what resources?

Water supply

– Over, under, around, or through?

– How much?

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Elevation is destiny for habitat

Tidal marsh?

Deep water/lake?

Riparian?

Floodplain?

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Delta of Tomorrow Will be Different, No Matter What We Do

Earthquake and flood risks Large bodies of open water and higher sea level

Losses of 15-20 islands where repair costs prohibitive

Major changes in:

– Water supply

– Water quality

– Delta land useBased on economic value of land and assets, many

islands not worth repairing after flooding (blue)

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Investment needs and beneficiaries

Levees (benefits mostly local land owners)

Water supply infrastructure (urban and agricultural users)

Ecosystem management (all)

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Long-term Water Supply Strategies

Today’s Dilemma

1. Through Delta

2. Around Delta

3. Dual conveyance

4. End Delta exports

How & how much around?

– Two tunnels

– One tunnel

– No tunnel

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The New Delta

Climate – sea level rise,

warmer

SGMA – More Delta

export demand

Declining native

ecosystems

Subsided island failures

Less export pumping

from new intake?

Others ...

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Challenges

1. Almost everyone sees unsustainability

2. Nobody want to commit to change

-> Game of chicken

3. All major decisions are expensive ($Bs), with major and dispersed beneficiaries. History of state bail-outs.

4. Highly dispersed authorities for all major issues makes decision-making and finance difficult

Reconciliation Strategy: Specialize Areas for Human and Ecosystem Functions

Current fish habitat Future specialized areas

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Water supply system portfolio actionsWater supply

Water Source availability Treatment

Capture of fog, precipitation, streams, groundwater, wastewater Existing water and wastewater treatment

Protection of source water quality New water and wastewater treatment

Conveyance capacities Wastewater reuse

Canals, pipelines, aquifers, tankers (sea or

land), bottles, etc.

Ocean Desalination

Contaminated aquifers

Storage capacities Operations

Surface reservoirs, aquifers and recharge,

tanks, snowpack, etc.

Reoperation of storage and conveyance

Conjunctive use

Water demands and allocation

Agricultural use efficiencies and reductions Ecosystem demand management

Urban water use efficiencies and reductions Recreation water use efficiencies

Incentives to work well together

Pricing Subsidies, taxes

Markets Education“Norming”, shaming

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Resistance is Futile1) Flooding in parts of the Delta

2) Reduced Delta diversions

3) Less irrigated land in the southern Central Valley

4) Less urban water use, more reuse & storm capture

5) Some native species unsustainable in the wild

6) Funding solutions mostly local and regional

7) State’s leverage is mostly regulatory, not funding

8) Nitrate groundwater contamination is inevitable

9) Groundwater will be managed more tightly

10) The Salton Sink will be largely restored

We cannot drought-proof, but we can manage better.18

Further Reading Jackson & Paterson (1977), The Sacramento–San Joaquin Delta and the Evolution and Implementation of Water Policy: An Historical Perspective, UC Water Resources Center

Lund et al. (2010) Comparing Futures for the Sacramento San Joaquin Delta, UC Press

Hanak et al. (2011) Managing California’s Water, PPIC.org

PPIC, Stress Relief: Prescriptions for a Healthier Delta Ecosystem, April 2013

DWR, WaterFix EIR/EIS, 2016

Mavensnotebook.com

CaliforniaWaterBlog.com

Hanak et al. (2010) Myths of California Water, PPIC.org

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