Environmental Science ENSC 2800

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Environmental Science ENSC 2800

• Spring 2002
• Class 4
• The Sacramento-San Joaquin Delta and Estuary and
  San Francisco Bay
• AKA The Bay-Delta
• Contextual Overview

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Bay-Delta regionpolitical geography (counties)
Source University of California's Center for
Environmental Design Research (CEDR)
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Bay-Delta region urbanization (1990) and
projected growth
Built-up areas (gray) Planned residential
(yellow) Planned industrial (light blue) Planned
commercial (purple).
Note the major urbanization planned around the
Delta cities of Sacramento, Stockton, and Tracy.
Source University of California's Center for
Environmental Design Research (CEDR)
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Bay-Delta historical terrestrial-aquatic margins
Source Preliminary map of historic margins of
marshland, San Francisco Bay, California / by
Donald R. Nichols and Nancy A. Wright. Menlo
Park United States Geological Survey, 1971.
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Bay-Delta hydrology is very complex
Note the tremendous number of individual streams
draining down toward the bay and estuary from
surrounding hills, adding to runoff from the
Sacramento and San Joaquin watersheds.
Source University of California's Center for
Environmental Design Research (CEDR)
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The Bay-Delta from Space (Spring 1994)
NASA Photo ID STS059-213-009
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Some Facts about the Bay-Delta (adapted from
CALFED 1999)

• Area of the watershed The system drains more
  than 61,000 square miles, or 37 of all
  California.
• Area of the Delta 738,000 acres.
• Annual runoff into it Inflow ranges from 2
  trillion gallons to 22.5 trillion gallons per
  year average is 7.8 trillion gallons.
• Diversions out of it Over 7,000 different
  entities divert water from the system into canals
  and pipes.
• Delta exports The State Water Project and
  Central Valley Project draw an average of about 4
  trillion gallons each year, mostly to southern
  CA.

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Major Southward Diversions from the Bay-Delta
Source CA DWR
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The major conveyance and storage infrastructure
in California (source DWR 1998)
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Source DWR 1998
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California rain and snow are mostly in the north
but the majority or people live south of
Sacramento.
Source DWR 1998
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Californias complex plumbing bypasses the
Bay-Delta or siphons water from it to send south.
Source DWR 1998
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Source DWR 1998
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Source DWR 1998
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Source DWR 1998
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Droughts in California occur in multi-year
periods and even without global warming, experts
expect much longer, dried periods in the future
based on ecological evidence.
Source DWR 1998
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Important Details About the Bay-Delta

• Delta flora Includes over 400 plant species, not
  including agricultural crops.
• Delta fauna Includes 225 birds, 52 mammals, and
  22 reptile and amphibian species.
• Delta fish Includes 130 fish species.
• Marshes The Delta still has 8,000 acres of tidal
  marsh (but originally there were 345,000 acres).
• Levees and channels Land adjacent to some 700
  miles of waterways are protected by 1,100 miles
  of levees.
• Delta farmland Over 52,000 acres are farmed,
  mostly for wheat, alfalfa, corn and tomatoes.
• Population Some 12 million people live and
  recreate in the Bay-Delta region.

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Bay-Delta Subject of Great Concern

• Owing to the economic and environmental
  importance of the Bay-Delta, the CALFED Bay-Delta
  Program was established by a State and Federal
  partnership in 1995 to address the many and
  complex issues facing the estuary system.
• It was set up in 1994 by President Bill Clinton
  and Governor Pete Wilson as part of the Bay-Delta
  Accord.
• CALFED's mission is to develop a long-term
  comprehensive plan that will restore ecological
  health and improve water management for
  beneficial uses of the Bay-Delta system.
• The full program, when implemented, will have
  cost some 9 billion to 10.5 billion in todays
  dollars, with about 5 billion going to increase
  water storage from wet to dry years.
• A massive range of programs are planned, funded
  by state and federal tax dollars and by payments
  from water purchasers.
• See http//www.calfed.water.ca.gov/general_info.h
  tml.