WaterWater

Key HKey H220 Characteristics0 Characteristics

• Water is the prime constituent of all living organisms.

• Water moves easily-from one physical state to another, and from one place to another.

• Water slowly absorbs and releases large quantities of energy.

• Water is a superior solvent.

• Michael D. Lee Ph.D. Geography and Environmental Studies(Source: Wright & Nebel 2002)

Importance of Water PropertiesImportance of Water Properties

Lack of access to clean water supplies can quickly lead to dehydration and death.

Running water can quickly erode topsoil rendering farmland infertile and streams contaminated.

Chemical spills, excess nutrients & acids dissolved in H20 can lead to massive die offs.

Michael D. Lee Ph.D. Geography and Environmental Studies

Available WaterAvailable Water• Total = 326 million cubic miles • 97% of Earth’s water is in

oceans• 2.997% is locked up in ice caps

and glaciers• 0.003% is easily accessible

– Soil moisture– Groundwater– Water vapor– Lakes– Streams

http://ga.water.usgs.gov/edu/waterdistribution.html

Water Supply & UseWater Supply & Use

Hydrologic CycleHydrologic Cycle• Powered by solar energy and gravity • Evaporation and precipitation • Continuous recycling of water

– Runoff – Infiltration – Evaporation – Temporary storage as snow and ice – Temporary storage in lakes – Temporary storage in plants (transpiration) and animals – Chemical reactions with rocks and minerals – Volcanism also causes melting of snow caps and

mudflows as melted water mixes with ash – Source of additional water? volcanism (steam)

Surface WaterSurface Water

• Surface runoff flows into streams, lakes, wetlands and reservoirs

• A watershed or drainage basin– Region that drains into a streams, lakes,

wetlands or reservoirs

www.canaanvi.org/assistance/ watershed.asp

GroundwaterGroundwater• As precipitation infiltrates and percolates

through voids in soil and rock– Pores, fractures, crevices, etc.

• Shallow rock has little moisture• Zone of saturation is at a depth were ground

is filled with water • Top of this zone is water table

– Falls in dry weather– Rises in wet weather

AquifersAquifers

• Porous, water-saturated layers of sand, gravel or bedrock through which groundwater flows

• Area of land that supplies water to aquifer is called the recharge area

• Natural recharge is when water percolates downward, but sometimes lateral recharge occurs

Groundwater MovementGroundwater Movement• Groundwater moves from recharge area

through an aquifer and out a discharge area– well, spring, lake, geyser, artesian well, steam,

ocean

• Normally moves downhill at only a meter per year

• Some aquifers get little recharge and were formed thousands of years ago

• Removal from these nonrenewable resources is called water mining

Use of Fresh WaterUse of Fresh WaterUnited States• 41% agriculture• 38% power plant cooling• 11% industry• 10% public

China• 87% agriculture• 7% industry• 6% public

Water UseWater Use Globally Globally People and Planet

• 70 per cent of all water withdrawn for human use on an annual basis is soaked up by agriculture (mostly in the form of irrigation)

• Industry accounts for 23 per cent

• Domestic use (household, drinking water, sanitation) accounts for about 7 per cent

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Water Use Water Use People and Planet

• The average person needs a minimum of five litres (1.3 gallons) of water per day to survive in a moderate climate at an average activity level, according to UN figures.

• The minimum amount of water needed for drinking and cooking, bathing and sanitation is 50 litres (13 gallons).

Water Use - Water Use - (minimum 13 gallons) (minimum 13 gallons) People and Planet

• The average person in the United States uses between 250 to 300 litres of water (65-78 gallons) per day for drinking, cooking bathing, and watering their yard.

• The average person in the Netherlands uses 104 litres per day (27 gallons).

• The average person in the African nation of Gambia uses 4.5 litres per day (1.2 gallons of water).

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Water Use - United StatesWater Use - United States• In 1990, about 408 billion gallons (Mgal/d) of

water were used each day

• Of that, about 339,000 Mgal/d was fresh water and about 69,400 Mgal/d was saline water

• California used the most water, about 46,800 Mgal/d, with most of that going towards irrigation

• The state with the second-highest water use was Texas, with about 25,200 Mgal/d, mostly for use in the power-production industries and for irrigation

• WaterWater– Supply, Renewal and Use

–Too little WaterToo little Water– Dams and Reservoirs– Transferring water– Groundwater and Saltwater– Efficiency– Too Much Water

• Water Pollution

Too Little WaterToo Little Water

• Causes– Dry climate– Drought - a period in which precipitation is

much lower and evaporation is much higher– Desiccation - drying of soil because of such

activities as deforestation and overgrazing– Water stress - low per capita availability of

water caused by overpopulation

Precipitation Varies GreatlyPrecipitation Varies Greatly• US cities vary in their precipitation from an

average of less than 8 to 60 inches a year.• Globally, the extreme is even greater –

averages of less than 1 inch to more than 70 inches per year.

• However, this masks variations between years.

• Some locations may get ten times more, or less than 1/10 of their annual average from year to year.

• Meeting demands for water when precipitation is so highly varied creates many challenges.

whyfiles.org/131fresh_water/ 2.html

www.geocities.com/seafloormapping2/ atmos.htm

http://www.peopleandplanet.net/graphs/Freshwateravailability.jpg

Egyptians perfected the shadouf to draw water from canals and the river to the adjacent bank and into ditches.

Nomadic herders and, later, sedentary civilizations developed chains of wells – qanats, karez, foggaras, falaj – to route water across miles of desert from distant aquifers.

Michael D. Lee Ph.D. Geography and Environmental Studies

Water for PowerWater for Power• In addition to its uses for municipal purposes (drinking,

sanitation, etc.) and for farming, moving water also has tremendous power to do work.

• This too has been harnessed for millennia – first to lift water out of the river itself, then to grind grain and turn gears for machinery like looms, and then for electricity.

• Water wheels have been in use for more than 2,000 years and were thought to have been a major factor in the advancement of European societies in the middle ages, as labor was freed for other purposes than farming.

• Following the discovery of electricity and the pioneering of electric light by Edison, in the 1880s hydropower systems were built to generate electricity to send through transmission lines to homes and businesses.

Michael D. Lee Ph.D. Geography and Environmental Studies

Slaters Mill in Rhode Island, one of the earliest American water powered industrial systems.

Example of noria – water driven wheels lifting water into irrigation ditches or elevated aqueducts (This is in Vietnam)

Artists impression of the Three Gorges Project, Yangtze River, China – world’s biggest hydropower project 19 m kW.

Michael D. Lee Ph.D. Geography and Environmental Studies

Increasing Water Supplies

• Build dams and reservoirs to store runoff

• Bring in surface water from another area

• Withdraw groundwater

• Convert salt water to fresh water (desalination)

• Improve the efficiency of water use

Hoover Damwww.wvic.com/res-main.htm

Aswan Dam, Egypt

Fish Bypass System

Chinese Dam

Earthen Dam

Large Dams - ProsLarge Dams - Pros

• Collect and store water from rain and snow

• Produce electricity

• Irrigate land below the dam

• Control flooding

• Provide water to cities, towns and rural areas

• Provide recreational activities such as swimming, boating, fishing

Large Dams - ConsLarge Dams - Cons

• Enormous loss of water due to evaporation

• Mass of water can cause earthquakes

• Flooded land destroys forests or cropland and displaces people

• Danger of Dam collapse

• Downstream areas deprived of nutrient-rich soil, which will eventually clog the reservoir

• Migration and spawning of fish disrupted

• Expensive to build

California’s Water• Water Law

• California’s Water Projects– Los Angeles Aqueduct– Hetch-Hetchy– Salton Sea– Colorado Aqueduct– Central Valley Project

Water LawWater Law• Riparian Rights (Sharing)

– from English Common Law

– applies to surface waters

– owner of waterfront land to use amounts correlated with other riparian owners.

– Works well in areas with water surplus

• Prior Appropriation (1st come, first served)– from Spanish law

– no preference given to those adjoining water course

– water rights based on use; earliest has rights

– use protected as long as it is continuous and “reasonable”

Los Angeles Aqueduct (DWP)Los Angeles Aqueduct (DWP)Eastern Sierra

• Started in 1908 by William Mulholland • appropriated water feeding Owens Valley• taps surface flow from Eastern Sierra south• 250 miles, cost $25,000,000 and took five years• pipe and flume, tunnel, and trench• gravity feed, no pumping• generates hydroelectric power• L.A. purchased riparian land, used appropriation rights to

get away with this. Ranchers in Owens Valley fought back with dynamite and guns - California’s only range war.

LA Aqueduct is

Mono LakeMono Lake • In 1941, L.A. DWP started diverting Mono Basin streams to add to L.A. Aqueduct.

• Mono Lake’s volume halved while salinity doubled. The simple ecosystem began to fail and threatened migrating birds and nesting gulls.

• The state and courts now mandate raising the level of the lake 17 feet. It will take about 20 years.

Hetch Hetchy:Hetch Hetchy:San Francisco Water

• Hetch Hetchy Valley, in Yosemite National Park, dammed. Completed in 1931.

• 175 mile aqueduct and O’Shawnasy Dam, powerhouse, provide cheap power to the city of San Francisco.

• 95 mile Mokelumne aqueduct, starts at Pardee Dam and reservoir.

• Together they provide about 1/3 of Bay Area water.• Controversy helped to strengthen John Muir’s Sierra

Club.

www.westernlaw.org/fischer/ 7_6text.html

The Salton SeaThe Salton Sea• Man-made by accident in 1905. • Irrigation in Imperial Valley had flooded an ancient

overflow channel of the Colorado River.• Unusually heavy spring runoff and lack of control

gates caused a two-year flood into the Salton Sink.• The Southern Pacific Railroad had to move its tracks

five times that season to higher ground. • Eventually the S.P.R.R. took control and put the river

back but by then the Salton Sea was created.• Hoover Dam now controls Colorado and prevents

delivery of sediment to Yuma and the delta.

Colorado River AqueductColorado River Aqueduct• Established 1928 to bring water to L.A. and rest of

Southern California

• First delivery in 1940; serves 15 million people

• Lawsuit from Arizona (1953) finally began to be implemented in 1985 - amount will decrease and this amount will be replaced by State Water Project water.

• Five pumping stations

• Diversions for agriculture

The State Water Project: The State Water Project: The California AqueductThe California Aqueduct

• Constructed beginning in the 1960s.• About 1/2 for irrigation, about 1/2 for

domestic use.• Domestic use supply helps offset that lost to

Arizona in 1985 court case.• Includes the huge Oroville Dam on Feather

River in Sierra foothills. • Pumps at Tracy lift water, then it flows by

gravity to the Tehachapi Mountains.

Dams and Global Dams and Global River River

DegradationDegradation

Aswan Dam, Egypt Lake NasserAswan Dam, Egypt Lake Nasser

Shasta Dam, CAShasta Dam, CA

Upstream of Dams - Negative Impact Upstream of Dams - Negative Impact • Environment

– Loss of terrestrial/riparian habitat and species

– Creation of artificial lacustrine (lakes) system

– exotic species introductions– Reservoir/storage for contaminants

• Cultural / social– Loss of cultural resources– Displacement of families (villages,

regions)– Water quality hazard

• Economic– Shift in land use / economy– Water loss via evaporation– Water loss via seepage

• Aesthetic– landscape inundated

DownstreamDownstreamImpacts of DamsImpacts of Dams

• Altered hydrology - no seasonality• Altered water quality/character• Modify nutrient cycling• Reduce sediment supply• Channel adjustments• Habitat modification• Species impacts• River fragmentation

The ‘Dam’ BalanceThe ‘Dam’ Balance• Some dam removal (small dams) or

operational changes (larger dams)• Bruce Babbit (Secretary of the Interior)

oversaw the creative destruction of two California dams in 2000 – Saelzer Dam on Clear Creek near Redding, for Salmon– Matilija Dam in Southern California

• Dams continue to be built until good sites are gone, or it is not economic to build them.

• Global numbers? We do not know

Three Gorges DamThree Gorges Dam• World's largest hydroelectric dam, Three Gorges,

Yangtze River. • 1.2 - 1.9 million people will be displaced.

• The entire project is to be completed in 2009.

Summary of California Water Summary of California Water SystemsSystems

• Very complicated.

• Politically controversial - Owens Valley, Dams, Habitat changes, reduced flushing of SF Bay Delta.

• California has the most advanced and expensive water delivery system in the world.

• Most of the water (about 80%) is used by agriculture; essential to California’s huge farm industry.

Michael D. Lee Ph.D. Geography and Environmental Studies

Tapping GroundwaterTapping Groundwater

• About half of the drinking water in the United States is pumped from aquifers

• Roughly 40% of the water in streams/river is from groundwater

• The number one removal of water from aquifers is for irrigation for farming

Groundwater ProblemsGroundwater Problems

• Aquifer depletion – more water is removed than is naturally

refreshed

• Aquifer subsidence – land sinks due to withdrawal of groundwater

(Mexico City)

• Intrusion of salt water into aquifers

• Contamination from multiple sources

Groundwater DGroundwater Depletionepletion • Aquifer Depletion

– 95% of water removed from Ogallala Aquifer is for irrigation and the removal rate is greater than the refreshing rate

– Saudi Arabia, China, northern Africa, southern Europe, Middle East, Thailand, India

www.npwd.org/Ogallala.htm

Aquifer SubsidenceAquifer Subsidence

• Mexico City’s aquifer has shrunk enough that land has dropped up to 7.5 m

http://www.geotimes.org/july01/sinking_titanic_city.html http://www.science.uwaterloo.ca/earth/waton/mexfig2.html

Well casing projecting from the ground (40 years)

Salt Water Salt Water IntrusionIntrusion

• “One-third of the water supply for coastal areas of Greater Los Angeles comes from local ground-water sources.

• Saltwater has penetrated a part of the supply, and a significant part of the remaining supply is at risk.”

• U.S. Geological Survey Fact Sheet 030–02

• Removal of salts from ocean water – reverse osmosis

using high pressure

• The Santa Barbara facility began operation in March 1992

http://www.tampabaywater.org/MWP/MWP_Projects/Desal/Desal.htm

DesalinationDesalinationhttp://urila.tripod.com/

Reducing Water WasteReducing Water Waste• Up 70% of water is lost through evaporation

& leaks

– repair leaky pipes/canals

– recycling • use of gray water (i.e. from shower) for irrigation etc.

– water conservation• efficient toilets, faucets, & shower heads

– irrigation efficiency (only 40% reaches crops)• drip irrigation, central–pivot, computer monitoring

Types of BenefitsTypes of Benefits

Possible benefits of canal replacement with pipeline:

• reduction in seepage losses• improvement of head and on-farm water

delivery• better operation of distribution network• reduction in maintenance costs

Direct Potable Water ReuseDirect Potable Water Reuse

TreatmentTreatment

WastewaterDrinking Water

Windhoek, NamibiaWindhoek, Namibia

• Population: 220,000

• Severe water shortage

• First and only city using direct potable water reuse (Since 1968)

Windhoek, NamibiaWindhoek, Namibia

• 40% of water demand returned as wastewater

• 2,000 m3/day of reclaimed water

• Basic public acceptance

• No significant epidemiological trends– Data consistent with WHO health trends

Denver, ColoradoDenver, Colorado

• Direct Potable Reuse demonstration project (1985-1992)

• Drinking water influent is secondary treated wastewater

• Several barriers of treatment– Standard Drinking Water Treatment– Carbon Adsorption– Ultraviolet Irradiation– Reverse Osmosis/Ultrafiltration– Air Stripping– Disinfection (ozonation and chlorination)

Denver, ColoradoDenver, Colorado

• High water quality (meets all EPA standards)

• No adverse health effects – Tested on animals– Carcinogenic and reproductive tests

• Public awareness and education programs– Majority of acceptance if sufficient need exists

Specific Uses for Recycled Water

• Subsurface drip irrigation– Safer

• Non-aerosolizing of water and pathogens

– More prone to clogging• Requires more maintenance

– More efficient• Less evaporative water loss

• Feeds roots of plants/grass directly

• Toilet flushing

Too Much Water: FloodsToo Much Water: Floods

• Natural flooding is caused primarily by heavy rain or rapid melting snow.

• This causes water in a stream to overflow it normal channel & flood the adjacent area, called a floodplain.

• Floodplains, which include highly productive wetlands, help to:—Provide natural flood & erosion control—Maintain high water quality—Recharge groundwater

• When the floodwater recede, deposits of silt are left behind, creating a nutrient-rich soil.

Too Much Water: FloodsToo Much Water: Floods

People have been settling in floodplains for several reasons:

1. Fertile soil2. Sufficient water for irrigation3. Flat land suitable for agriculture4. Use of nearby rivers for transportations

However, each year floods (“natural disasters”) kill thousands of people & cause tens of billons of dollar in property damage. Human activities have contributed to the sharp rice in flood frequencies which dramatically increased flood deaths & damages.

FloodingFloodingHuman activities that increase flooding:• removing vegetation• logging•overgrazing• forest fires•mining•destruction of wetlands

•building on floodplains

•urbanization © Brooks/Cole Publishing Company / ITP

Too Much Water: FloodsToo Much Water: Floods

Natural phenomenaNatural phenomena

Floodplain

Levee Floodwall

Dam

Reservoir

Renew and replenishRenew and replenish

Aggravated by human activities

Aggravated by human activities