Transcript California`s Water

California’s Water
California Water Resources Using a Web-Based
Geographic Information System
September 19, 2009
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California’s Water Issues
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Population Growth
Mismatch between where precipitation falls and where
most of the people, farms and industries are located
Drought
Deteriorating Sacramento - San Joaquin Delta
Seismic hazards
Pollution
Climate Change
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California’s Water System
The Delta: Geography and Stakeholders
Modified from a presentation by Richard Sedlock
SJSU Geology/BAESI
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The California Water Map (Water Education Foundation)
In simplified, big-picture terms, the major types of
uses/users of collected precipitation in California are:
“Developed” water
Agriculture
41 %
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Cities/industries
11 %
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“Environmental” water
Wild & Scenic Rivers
Delta outflow
“unused” flow to ocean
diversions to ag & cities
48 %
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take these percentages
with a grain of salt....
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California’s uses of water are not accidental, natural, or predetermined.
Our patterns of usage result from political, economic, and social decisions
of the last 150 years, made against the backdrop of roughly constant
climatic conditions.
In California, the agriculture industry obtains water at rates that are
subsidized, i.e., much lower than the market rate.
• The agriculture industry argues that subsidized rates are
needed to prevent high food prices.
• Water-intensive crops will be less profitable as water supplies
wane or become less dependable.
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The agriculture industry argues that subsidized water helps support
the California economy (13% of U.S. agricultural products in 2006).
Compare the agriculture industry’s contribution to California’s Gross
Domestic Product (below) with its water use.
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“The Delta”
THE
DELTA
Sacramento
River
+ hundreds of other
Suisun
Bay
waterways and islands
San Joaquin
River
Delta smelt
Longfin smelt
Both fish are fundamental parts of the food web in the Bay-Delta estuary.
Ecological conditions in the estuary have degraded badly in last 25 years.
Since 2003, the abundance of each is <3% of the 1993 abundance.
In May 2007, juvenile smelt populations were 8% of May 2006 populations.
Causes: (1) reductions in Delta’s freshwater outflow; (2) “entrainment”
due to water diversions; (3) changes in available food; (4) pesticides
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The Delta is a
key hub in the
Pacific Flyway
Levees near Stockton, CA
Jones Tract
Levee, 2004
Many levees in
the Delta are over
100 years old
Many islands are
15-20 feet below
sea level; sinking at
1.6 to 3 inches/yr
Expensive repairs and
proposed construction
The Peripheral Canal
Active faults (capable of M≥6 earthquake
The Delta
Area flooded by a
1-meter rise in sea
level
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Regions in the western
U.S. where water-supply
conflicts are likely to occur
by 2025, based on factors
such as population and
endangered species’ need
for water. Does not factor
in effects of climate
change, which are
expected to exacerbate
many of these conflicts.
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19% of
California’s
energy
expenditures
move water.
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Climate Change = Hydrologic Change
http://www.fs.fed.us/emphasis/products/water-climate-brochure.pdf
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Climate Change and Water in California
http://www.water.ca.gov/climatechange/docs/062807factsheet.pdf
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Climate Change Impacts to
California’s Water Resources
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By 2050: loss of at least 25 percent of the Sierra snowpack
More variable weather patterns
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More flooding and longer, more severe droughts
Rising water temperatures and changes in runoff patterns may
adversely impact salmon and other species.
Sea level rise will threaten many coastal communities as well as
the sustainability of the Sacramento-San Joaquin Delta.
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Salt water intrusion
http://www.water.ca.gov/climatechange/docs/062807factsheet.pdf
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http://www.water.ca.gov/climatechange/docs/062807factsheet.pdf
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Potential reduction in hydropower
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Increased population and greater demand for energy
Decreased snow melt flowing through = decreased
potential for hydropower production
However, future precipitation projections are uncertain.
Shasta dam
(USGS)
http://www.climatechoices.org/ca/site/ca/site/our-changing-climate.html
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California Education and the
Environment Initiative
Unit
Planner
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Unit
Planner,
continued
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