Transcript www.tceq.state.tx.us

California Water Briefing
Department of Water Resources
APRIL 2006
Overview
• Most populous state in U.S. – represents about 12%
of national population
• Estimated 2005 population of 37 million
• Projected 2020 population of 44 million
• Top agricultural production state in the nation for
more than 50 years.
• About 9 million acres of irrigated cropland
Physical Setting
• Majority of population is
located within 100 miles
from the Pacific Ocean,
from the San Francisco
Bay Area south to the
Mexican border
• The Central Valley
represents about 80%
of the irrigated
agricultural acreage
• Largely Mediterraneantype climate
Economic Setting
• 8TH largest economy in the world
• 2004 Gross State Product (GSP)
of $1.6 trillion
• Percentage contribution
to GSP by economic
sector shown at right
Hydrology Overview
• Average annual runoff from precipitation falling
on California is 71 MAF
• Average annual surface water supplies are the
71 MAF of in-state runoff plus 7 MAF from flows
in interstate rivers, for a total of 78 MAF
• More than 70% of the surface runoff occurs in
Northern California, while more than 70% of the
needs for water occur in Southern California
Importance of Sierra Snowpack
• Sierra Nevada runoff
supplies – directly or
indirectly (through
groundwater recharge) a
majority of California’s
urban and agricultural
water needs
• Relies on complicated
system of operating
Sierran reservoirs to
provide both water
storage and flood control
capacity
Mean Annual Precipitation in California, 1961 to 1990
Distribution of Average Annual Precipitation and Runoff
Groundwater
• Statewide, in an average
year groundwater supplies
about 30% of urban and
agricultural water uses.
• There are 431 delineated
groundwater basins in
California
Agricultural and Urban Demand Supplied by Groundwater in
Each Hydrologic Region
Groundwater Basins and Subbasins