1
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
2
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
3
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
4
SF Estuary & Delta Wetlands: 1848 and today
http://sfbay.wr.usgs.gov/access/yearbook.html
Delta, 1905
5
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
7
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
8
Climate Impacts
1. Sea level rise (1-3+ ft/century)
2. Higher temperatures
3. Seasonal shifts in inflows
4. More extreme floods and droughts
9
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?
10
Elevation is destiny for habitat
Tidal marsh?
Deep water/lake?
Riparian?
Floodplain?
11
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)
12
Investment needs and beneficiaries
Levees (benefits mostly local land owners)
Water supply infrastructure (urban and agricultural users)
Ecosystem management (all)
13
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
14
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 ...
15
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
3
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
17
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
?