WATER

The Hydrologic Cycle Water Basics –Sea water97.2% –Fresh Water 2.8% Polar ice & glaciers 2.15% Groundwater 0.62% Lakes and Rivers 0.01%

The Hydrologic Cycle The Three Fates of Precipitation –Infiltration The movement of water into rocks or soil through cracks and pore spaces –Runoff Water that flows over the land –Transpiration/Evapotranspiration the release of water vapor to the atmosphere by plants

The Hydrologic Cycle Running water is the single most important agent sculpturing Earth’s land surface –Begins as sheetflow –Sheetflow develops into tiny channels called rills

The Hydrologic Cycle Infiltration capacity of the soil is controlled by: –Intensity and duration of rainfall –Soil saturation –Soil texture –Slope of the land –Nature of the vegetative cover

What is Groundwater? Introduction –Water found in the pores and fractures of soil and bedrock –Largest reservoir of fresh water –Tends to be less polluted than surface water

What is Groundwater? An important erosional agent –Groundwater is often mildly acidic –Contains weak carbonic acid –Forms caverns at or just below the zone of saturation –Karst topography on the surface

What is Groundwater? Equalizer of streamflow –Most water percolates down into the Earth –Forms underground “streams”

Principles of Groundwater Terms –Porosity Percentage of void space in a rock/soil –Permeability The ability of a material to transmit a fluid

Principles of Groundwater Terms (continued) –Specific retention The portion whish is retained as a film on particles, rock surfaces, and pore spaces –Specific yield The portion which will drain under gravity –In general, Porosity = Specific retention + Specific yield

Principles Of Groundwater Terms (continued) –Aquifer A zone of Earth material capable of supplying groundwater at a useful rate from a well Mostly sands and gravels deposited in stream channels in California

Principles Of Groundwater Terms (continued) –Aquitard A zone of Earth material that holds water but cannot transmit it fast enough to pump from a well Usually forms a confining layer

Principles of Groundwater Groundwater basins –“an area underlain by permeable materials capable of furnishing a significant supply of groundwater to wells or storing a significant amount of water”

Principles of Groundwater Terms (continued) –Groundwater basin boundaries Impermeable Bedrock Constrictions in Permeable Materials Fault Low Permeability Zone Groundwater Divide Adjudicated Basin Boundaries

Principles of Groundwater Movement of Groundwater –Very slow - centimeters/day –Measuring groundwater flow

Getting Groundwater Out of the Ground Extraction Methods –“Natural” Methods Springs Hot Springs Geysers

Hot Spring locations in the United States

The USGS monitors springs, streams, wells, fumaroles, and precipitation in Long Valley to study the natural hydrologic variations and the response of the hydrologic system to volcanic and tectonic processes.

Getting Groundwater Out of the Ground Extraction Methods (continued) –Man-made Methods Wells

Getting Groundwater Out of the Ground Artesian well/spring –A situation in which groundwater under pressure rises above the level of the aquifer –Types of artesian wells Nonflowing – pressure surface is below ground level Flowing – pressure surface is above the ground

Getting Groundwater Out of the Ground Problems with groundwater removal –Non-renewable resource –Subsidence –Contamination

Groundwater In Southern California Geological Setting –S. California is broken into fault blocks of different elevation –Sediment deposited on the lower blocks forms the aquifers

Groundwater In Southern California Coastal Plain –These areas are formed by alluvial deposits of the LA, San Gabriel, and Santa Ana Rivers –Unconfined aquifers lie just beyond the narrows

Los Angeles County, California Hydrologic Unit Code Latitude 34°05'35", Longitude 117°57'35" NAD27 Gage datum 387 feet above sea level NGVD29 The depth of the well is feet below land surface. The depth of the hole is 200 feet below land surface.

Groundwater In Southern California Inland Valleys –Water here drains in the subsurface through the narrows to the coastal plain –San Fernando Valley Has extensively used groundwater for agriculture and domestic needs Now polluted with TCE - a Superfund site Has also used Owens Valley water since 1915

Groundwater In Southern California –San Gabriel Valley Groundwater is heavily used Basin has the storage capacity of 10 million acre feet The San Gabriel Basin is polluted with cancer causing chemicals –trichloroethylene (TCE) –perchloroethylene (PCE) –carbon tetrachloride (CTC)

Groundwater In Southern California –San Gabriel Valley (continued) San Gabriel Valley became a Superfund site in 1985 More than 1 million people rely on the San Gabriel aquifer for drinking water.

Sea Water Intrusion This is a worldwide problem –First recognized here at Redondo Beach in 1912 –LA County Department of Public Works is responsible for prevention

Sea Water Intrusion The Barrier Projects –West Coast Basin Barrier Project 10 miles from El Segundo to Palos Verdes –Dominguez Gap Barrier 6 miles from San Pedro to Long Beach –Alamitos Barrier Project 7 miles from Long Beach to Seal Beach

Methods Of Augmenting Local Water Supplies Water Importation by Aqueducts Water Reclamation Desalination Icebergs

History Of Aqueducts In California

Owens Valley Aqueduct

History Of Aqueducts In California Owens Valley Aqueduct –Concept resulted from the drought of which threatened the growth of LA –Conceived by Fred Eaton and William Mulholland –US Reclamation Service interested in area for irrigation purposes J.B. Lippincott, Fred Eaton and William Mulholland. This photograph appeared in the Los Angeles Times, August 6, 1906.

History Of Aqueducts In California Owens Valley Aqueduct –1904 – LA agents secretly buy options on land with water rights –1905 – Preliminary bond measure approved –1906 – Congress grants aqueduct right of way over federal land with strong backing from President Theodore Roosevelt –1907 – Full bond measure for $25M approved

History Of Aqueducts In California Owens Valley Aqueduct –1913 – Construction of aqueduct completed –1915 – San Fernando Valley annexed into LA –1924 – Owens Lake and ~50 miles of the Owens River are dry –1930 – 95% of Owens Valley farmland owned by Los Angeles; $40M bond issue approved to expand aqueduct into Mono Basin –1940 – Extension completed, diversions begun

History Of Aqueducts In California Owens Valley Aqueduct –1963 – plans for a second aqueduct approved –1970 – DWP plans to fill new aqueduct by: Reducing irrigation water Diverting surface water from Inyo and Mono counties Pumping groundwater –1972 Inyo county successfully sued to stop groundwater pumping increase Wetland meadows, seeps, springs, and marshes dried and disappeared, well water levels dropped, and vegetation in the valley began to change.

History of Aqueducts in California Owens Valley Aqueduct –Opposition to the aqueduct Began in Owens Valley with the first land acquisitions in 1905 Still controversial today

History of Aqueducts in California Colorado River Aqueduct –Droughts from the mid-1920's to early 1930's resulted in 500,000 people of LA approving a $220 million bond issue in 1931 for a new aqueduct

History of Aqueducts in California Colorado River Aqueduct –The MWD (128 cities, 12 million people) built the Colorado River Aqueduct Extends 242 miles from Lake Havasu behind Parker Dam 4 pumping stations Supplied 1.2 million acre-ft/year to S. California for many years Now reduced to 550,000 acre-ft/year Supplies 6% of LA's needs Supplies East LA, the Harbor & part of the central city

History of Aqueducts in California California Aqueduct –2.5 million people of LA approved a $1.75 billion water project –Aqueduct stretches 444 miles from Oroville Dam –Deliveries began in 1971

History of Aqueducts in California Future Aqueducts are unlikely –Belief that more water means more people and more pollution –Water rationing first occurred in LA on July 1, 1977

Who Does What With Water Federal Level –USGS measures water resources –EPA Pollution control and enforcement

Who Does What With Water State Level –Department of Water Resources

Who Does What With Water County Level –Department of Public Works –County Sanitation Districts

Who Does What With Water City Level –LA Department of Water and Power –Metropolitan Water Districts cities –Local water companies –Local sewage companies

The Use Of Water Agriculture - by far the greatest user –Uses 83% of state water –Great waste here

The Use of Water Residential 14.5% of state water –Some examples of water use at home Full bathtub - 36 gallons Shower - 25 gallons per 4 minutes Wash dishes - 30 gallons Flush toilet - 7 gallons Sprinkle lawn - 10 gal/minute, usually 1500 gallons Brushing teeth with water running gallons

The Use of Water Fish and Wildlife –2% of state water Power Plant Cooling –0.1% of state water

Water Quality - Nation Wide Legislation and Enforcement –Major Legislation - Federal Federal Water Pollution Control Act (Clean Water Act) of 1948 Water Quality Improvement Act of 1970 Water Pollution Control Act 1972 Toxic Substance Control Act 1976 Clean Water Act 1977 Clean Air Act of 1990

Water Quality - Nation Wide Legislation and Enforcement –EPA requires that states establish and enforce water quality standards Standards in California are established by the State Dept of Water Resources

Water Quality - Nation Wide Acid Rain –Acid rain has become an international problem US - Canada England – Norway

Water Quality - Nation Wide –Acid rain appears to be killing lakes, streams, forests, and people Acid rain may kill 50,000 people per year in the US (LA Times - 1/1982)

Water Quality - Nation Wide –Acid rain is caused by: CO 2 from cars and power plants NO x from cars SO 2 from power plants

Land Use in Southern California