Chapter 13 Chapter 13 Water ResourcesWater Resources

Key HKey H220 Characteristics0 Characteristics

Water is the prime Water is the prime constituent of all living constituent of all living organisms.organisms.

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

Water slowly absorbs and Water slowly absorbs and releases large quantities of releases large quantities of energy.energy.

Water is a superior solvent.Water is a superior solvent.

Freshwater Is an Freshwater Is an Irreplaceable Resource That Irreplaceable Resource That

We Are Managing PoorlyWe Are Managing Poorly Access to water is Access to water is

A global health issueA global health issue An economic issueAn economic issue A women’s and children’s issueA women’s and children’s issue A national and global security issueA national and global security issue

Water’s Unique PropertiesWater’s Unique Properties Strong hydrogen bonds hold water Strong hydrogen bonds hold water

molecules togethermolecules together The temperature of water changes slowly The temperature of water changes slowly

due to its high specific heat capacitydue to its high specific heat capacity Water has a high boiling pointWater has a high boiling point A lot of energy is needed to evaporate A lot of energy is needed to evaporate

waterwater Water filters out UV radiation im quatic Water filters out UV radiation im quatic

systemssystems Water expands upon freezingWater expands upon freezing

Available WaterAvailable Water Total = 326 million cubic miles Total = 326 million cubic miles 97% of Earth’s water is in oceans97% of Earth’s water is in oceans 3% Freshwater3% Freshwater

2.997% is locked up in ice caps and 2.997% is locked up in ice caps and glaciersglaciers

0.003% is easily accessible 0.003% is easily accessible Soil moistureSoil moisture GroundwaterGroundwater Water vaporWater vapor LakesLakes StreamsStreams

www.athensclarkecounty.com/~stormwater/ SW%20Management.htm

Water CycleWater Cycle

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

RunoffRunoff InfiltrationInfiltration EvaporationEvaporation Temporary storage as snow and ice Temporary storage as snow and ice Temporary storage in lakes Temporary storage in lakes Temporary storage in plants Temporary storage in plants

((transpirationtranspiration) and animals ) and animals Chemical reactions with rocks and Chemical reactions with rocks and

minerals minerals

Surface WaterSurface Water Surface runoff flows into streams, Surface runoff flows into streams,

lakes, wetlands and reservoirslakes, wetlands and reservoirs A watershed or drainage basinA watershed or drainage basin

Region that drains into a streams, Region that drains into a streams, lakes, wetlands or reservoirslakes, wetlands or reservoirs

www.canaanvi.org/assistance/ watershed.asp

GroundwaterGroundwater As precipitation infiltrates and As precipitation infiltrates and

percolatespercolates through voids in soil and through voids in soil and rockrock Pores, fractures, crevices, etc.Pores, fractures, crevices, etc.

Shallow rock has little moistureShallow rock has little moisture Zone of saturationZone of saturation is at a depth were is at a depth were

ground is filled with water ground is filled with water Top of this zone is Top of this zone is water tablewater table

Falls in dry weatherFalls in dry weather Rises in wet weatherRises in wet weather

Fig. 13-3, p. 316

Unconfined Aquifer Recharge Area

Precipitation Evaporation and transpiration Evaporation

Confined Recharge Area

Runoff

Flowing artesian well Well requiring a

pumpStream

InfiltrationWater table

LakeInfiltrationUnconfined aquiferLess permeable

material such as clay

Confined aquiferConfining impermeable rock layer

HOW RIVERS WORK: the role of

groundwater

www.elmhurst.edu/.../chm110/ outlines/groundwater.html

AquifersAquifers Porous, water-saturated layers of Porous, water-saturated layers of

sand, gravel or bedrock through sand, gravel or bedrock through which groundwater flowswhich groundwater flows

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

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

Groundwater MovementGroundwater Movement Groundwater moves from recharge Groundwater moves from recharge

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

steam, oceansteam, ocean Normally moves downhill at only a Normally moves downhill at only a

meter per yearmeter per year Some aquifers get little recharge and Some aquifers get little recharge and

were formed thousands of years agowere formed thousands of years ago Removal from these nonrenewable Removal from these nonrenewable

resources is called water miningresources is called water mining

Aquatic life zones cover almost three-Aquatic life zones cover almost three-fourths of the earth’s surfacefourths of the earth’s surface SaltwaterSaltwater: : marine marine

EstuariesEstuaries Coastal wetlandsCoastal wetlands Coral reefsCoral reefs Mangrove forestsMangrove forests Open OceanOpen Ocean

Aquatic SystemsAquatic Systems

• Freshwater• Lakes• Rivers and streams• Inland wetlands

Ocean ZonesOcean Zones Euphotic zoneEuphotic zone: brightly lit surface layer: brightly lit surface layer

Nutrient levels low, dissolved ONutrient levels low, dissolved O22 high, plenty of high, plenty of photosynthetic activity.photosynthetic activity.

Bathyal zoneBathyal zone: dimly lit middle layer: dimly lit middle layer No photosynthetic activity, zooplankton and fish No photosynthetic activity, zooplankton and fish

live there and migrate to euphotic zone to feed.live there and migrate to euphotic zone to feed.

Abyssal zoneAbyssal zone: dark bottom layer: dark bottom layer Very cold, little dissolved OVery cold, little dissolved O22.. High nutrient levels – filter down from the layers High nutrient levels – filter down from the layers

aboveabove UpwellingUpwelling – nutrients are brought to the surface by currents – nutrients are brought to the surface by currents

Major Life Zones and Vertical Zones in an Major Life Zones and Vertical Zones in an OceanOcean

Freshwater life zones Freshwater life zones include:include: Standing Standing ((lenticlentic) )

waterwater lakes, ponds, and inland lakes, ponds, and inland

wetlandswetlands

Flowing Flowing ((loticlotic)) systemssystems

streams and riversstreams and rivers

Why Are Freshwater Ecosystems Important?Why Are Freshwater Ecosystems Important?

Lakes are large natural bodies of standing Lakes are large natural bodies of standing freshwater formed from precipitation, runoff, freshwater formed from precipitation, runoff, and groundwater seepage consisting of:and groundwater seepage consisting of:

Littoral zoneLittoral zone (near shore, shallow, with rooted plants)(near shore, shallow, with rooted plants)

Limnetic zoneLimnetic zone (open, offshore area, sun-lit)(open, offshore area, sun-lit)

Profundal zoneProfundal zone (deep, open water, too dark for (deep, open water, too dark for photosynthesis)photosynthesis)

Benthic zoneBenthic zone (bottom of lake, nourished by dead (bottom of lake, nourished by dead matter)matter)

Water Stands in Some Water Stands in Some Freshwater Systems and Flows Freshwater Systems and Flows

in Othersin Others

Distinct Zones of Life in a Fairly Distinct Zones of Life in a Fairly Deep Temperate Zone LakeDeep Temperate Zone Lake

During the summer and winter, lakes become During the summer and winter, lakes become stratified into temperature layers.stratified into temperature layers.

In the spring and fall, the temperature equalizes In the spring and fall, the temperature equalizes and the lakes “overturn”.and the lakes “overturn”. Oxygen is brought from the surface to the lake Oxygen is brought from the surface to the lake

bottom and nutrients from the bottom are brought to bottom and nutrients from the bottom are brought to the top.the top.

Turnover in a LakeTurnover in a Lake

Some Lakes Have More Some Lakes Have More Nutrients Than OthersNutrients Than Others

Plant nutrients from a lake’s environment Plant nutrients from a lake’s environment affect the types and numbers of organisms it affect the types and numbers of organisms it can support.can support.

OligotrophicOligotrophic (poorly nourished) lake: Usually (poorly nourished) lake: Usually newly formed lake with small supply of plant newly formed lake with small supply of plant nutrient input.nutrient input.

Mesotrophic Mesotrophic (medium nourished) lake: most (medium nourished) lake: most lakes are in betweenlakes are in between

EutrophicEutrophic (well nourished) lake: Over time, (well nourished) lake: Over time, sediment, organic material, and inorganic sediment, organic material, and inorganic nutrients wash into lakes causing excessive plant nutrients wash into lakes causing excessive plant growth.growth.

Cultural eutrophicationCultural eutrophication:: Human inputs of nutrients from the Human inputs of nutrients from the

atmosphere and urban and agricultural areas atmosphere and urban and agricultural areas can accelerate the eutrophication process.can accelerate the eutrophication process.

Some Lakes Have More Some Lakes Have More Nutrients Than OthersNutrients Than Others

Water flowing from mountains to the sea creates Water flowing from mountains to the sea creates different aquatic conditions and habitats.different aquatic conditions and habitats.

Freshwater Streams and Rivers Freshwater Streams and Rivers Carry Water from the Carry Water from the

Mountains to the Oceans Mountains to the Oceans

Watershed Watershed or or drainage basindrainage basin the land area that the land area that

delivers runoff, delivers runoff, sediment, and sediment, and dissolved substance to dissolved substance to a stream or river.a stream or river.

The larger the The larger the watershed, the larger watershed, the larger the river it feeds into.the river it feeds into.

Freshwater Streams and Rivers Freshwater Streams and Rivers Carry Water from the Carry Water from the

Mountains to the Oceans Mountains to the Oceans

Inland wetlands Inland wetlands act act like natural sponges like natural sponges that absorb and store that absorb and store excess water from excess water from storms and provide a storms and provide a variety of wildlife variety of wildlife habitats.habitats.

Freshwater Inland Wetlands Freshwater Inland Wetlands Are Vital SpongesAre Vital Sponges

Filter and degrade pollutants. Reduce flooding and erosion by absorbing slowly

releasing overflows. Help replenish stream flows during dry periods. Help recharge ground aquifers. Provide economic resources and recreation.

Freshwater Inland Wetlands Freshwater Inland Wetlands Are Vital SpongesAre Vital Sponges

Water Use Globally Water Use Globally People and PlanetPeople and Planet

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

Industry accounts for 23 Industry accounts for 23 per- cent per- cent

Domestic use (household, Domestic use (household, drinking water, sanitation) drinking water, sanitation) accounts for about 7 per- accounts for about 7 per- centcent

0

10

20

30

40

50

60

70

Irrigation

Industry

Domestic

Water Use Water Use People and PlanetPeople and Planet

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

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

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

Planet Planet

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

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

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

0

50

100

150

200

250

UnitedStates

Netherlands

Gambia

Water Use - United StatesWater Use - United States In 1990, about 408,000 million gallons In 1990, about 408,000 million gallons

(Mgal/d) of water were used each day(Mgal/d) of water were used each day Of that, about 339,000 Mgal/d was fresh Of that, about 339,000 Mgal/d was fresh

water and about 69,400 Mgal/d was water and about 69,400 Mgal/d was saline watersaline water

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

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

WaterWater Supply, Renewal and UseSupply, Renewal and Use

Too little WaterToo little Water Dams and ReservoirsDams and Reservoirs Transferring waterTransferring water Groundwater and SaltwaterGroundwater and Saltwater EfficiencyEfficiency Too Much WaterToo Much Water

Too Little WaterToo Little Water

CausesCauses Dry climateDry climate Drought - a period in which precipitation is Drought - a period in which precipitation is

much lower and evaporation is much highermuch lower and evaporation is much higher DesiccationDesiccation - drying of soil because of such - drying of soil because of such

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

water caused by overpopulationwater caused by overpopulation

Precipitation Varies Precipitation Varies GreatlyGreatly

• 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.

Average Average Annual Annual

Precipitation Precipitation and Major and Major

Rivers, Water-Rivers, Water-Deficit Regions Deficit Regions

in U.S.in U.S.

Fig. 13-4a, p. 317

Average annual precipitation (centimeters)

41–81 More than 122

Less than 41 81–122

Fig. 13-4b, p. 317

Shortage

Acute shortage

Adequate supply

Metropolitan regions with population greater than 1 million

Fig. 13-5, p. 318

Substantial conflict potential

Highly likely conflict potential

Unmet rural water needs

Moderate conflict potential

Washington

Oregon

MontanaNorth Dakota

Idaho South Dakota

Wyoming

Nevada NebraskaUtah

ColoradoKansas

CaliforniaOklahoma

New Mexico

Texas

Arizona

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

In most In most areas of areas of Nevada and Nevada and California, California, potential potential transpiratiotranspiration and n and evaporation evaporation is in excess is in excess of of precipitatioprecipitation, which n, which causes a causes a net net moisture moisture deficitdeficit

Water Shortages Will GrowWater Shortages Will Grow Dry climateDry climate

DroughtDrought

Too many people using a normal Too many people using a normal supply of watersupply of water

Water Shortages Will GrowWater Shortages Will Grow Wasteful use of waterWasteful use of water

China and urbanizationChina and urbanization

Hydrological povertyHydrological poverty

Fig. 13-6, p. 319

Europe Asia

North America

Africa

South America

Australia

Stress

High None

Long-Term Severe Drought Long-Term Severe Drought Is IncreasingIs Increasing

CausesCauses Extended period of below-normal rainfallExtended period of below-normal rainfall Diminished groundwaterDiminished groundwater

Harmful environmental effectsHarmful environmental effects Dries out soilsDries out soils Reduces stream flowsReduces stream flows Decreases tree growth and biomassDecreases tree growth and biomass Lowers net primary productivity and Lowers net primary productivity and

crop yieldscrop yields Shift in biomesShift in biomes

In Water-Short Areas In Water-Short Areas Farmers and Cities Compete Farmers and Cities Compete

for Water Resourcesfor Water Resources 2007: National Academy of Science 2007: National Academy of Science

studystudy Increased corn production in the U.S. to Increased corn production in the U.S. to

make ethanol as an alternative fuelmake ethanol as an alternative fuel Decreasing water suppliesDecreasing water supplies Aquifer depletionAquifer depletion Increase in pollution of streams and aquifersIncrease in pollution of streams and aquifers

WaterWater Supply, Renewal and UseSupply, Renewal and Use Too little WaterToo little Water

Dams and Reservoirs and Dams and Reservoirs and Transferring waterTransferring water Groundwater and SaltwaterGroundwater and Saltwater EfficiencyEfficiency Too Much WaterToo Much Water

Water and CivilizationWater and Civilization Many anthropologists and historians Many anthropologists and historians

believe the need to manage water believe the need to manage water played a major role in the development played a major role in the development of early systems of government.of early systems of government.

In Mesopotamia, the Fertile Crescent where the In Mesopotamia, the Fertile Crescent where the Tigris and Euphrates Rivers come together, Tigris and Euphrates Rivers come together, water allowed the rise of irrigation-based water allowed the rise of irrigation-based agriculture, but this required coordination and agriculture, but this required coordination and rules to permit equitable access to water rules to permit equitable access to water downstream.downstream.

Ancient communities that Ancient communities that prospered were those that prospered were those that generally well managed generally well managed their water supplies.their water supplies.

Examples of Water ManagementExamples of Water Management Many civilizations built impressive Many civilizations built impressive

water management systemswater management systems.. Egyptians built dykes, canals and water Egyptians built dykes, canals and water

lifts to extend agricultural limits.lifts to extend agricultural limits. Middle East and North African nomads Middle East and North African nomads

built qanats (underground chain wells).built qanats (underground chain wells). Nabateans built runoff harvesting Nabateans built runoff harvesting

systems – cisterns and flood terraces.systems – cisterns and flood terraces. Incas built canals to catch snowmelt Incas built canals to catch snowmelt

from the Andes to the coastal desert, from the Andes to the coastal desert, and terraces to flood for farming.and terraces to flood for farming.

Romans built municipal aqueducts and Romans built municipal aqueducts and sewers to serve burgeoning sewers to serve burgeoning settlements.settlements.

Water for PowerWater for Power Moving water also has tremendous power Moving water also has tremendous power

to do work.to do work. This too has been harnessed for millennia – This too has been harnessed for millennia –

first to lift water out of the river itself, then first to lift water out of the river itself, then to grind grain and turn gears for machinery to grind grain and turn gears for machinery like looms, and then for electricity.like looms, and then for electricity. Water wheelsWater wheels have been in use for more than 2,000 have been in use for more than 2,000

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

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

Increasing Water SuppliesIncreasing Water Supplies

Build dams and reservoirs to store Build dams and reservoirs to store runoffrunoff

Bring in surface water from another Bring in surface water from another areaarea

Withdraw groundwaterWithdraw groundwater Convert salt water to fresh water Convert salt water to fresh water

(desalination)(desalination) Improve the efficiency of water useImprove 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 snowCollect and store water from rain and snow Produce electricityProduce electricity Irrigate land below the damIrrigate land below the dam Control flooding Control flooding Provide water to cities, towns and rural Provide water to cities, towns and rural

areasareas Provide recreational activities such as Provide recreational activities such as

swimming, boating, fishingswimming, boating, fishing

Large Dams - ConsLarge Dams - Cons Enormous loss of water due to evaporationEnormous loss of water due to evaporation Mass of water can cause earthquakesMass of water can cause earthquakes Flooded land destroys forests or cropland Flooded land destroys forests or cropland

and displaces peopleand displaces people Danger of dam collapseDanger of dam collapse Downstream areas deprived of nutrient-Downstream areas deprived of nutrient-

rich soil, which will eventually clog the rich soil, which will eventually clog the reservoirreservoir

Migration and spawning of fish disruptedMigration and spawning of fish disrupted Expensive to buildExpensive to build

Water LawWater Law Riparian RightsRiparian Rights (Sharing) (Sharing)

from English Common Lawfrom English Common Law applies to surface watersapplies to surface waters owner of waterfront land to use amounts correlated owner of waterfront land to use amounts correlated

with other riparian owners.with other riparian owners. Works well in areas with water surplusWorks well in areas with water surplus

Prior AppropriationPrior Appropriation (1st come, first served) (1st come, first served) from Spanish lawfrom Spanish law no preference given to those adjoining water courseno preference given to those adjoining water course water rights based on use; earliest has rightswater rights based on use; earliest has rights use protected as long as it is continuous and use protected as long as it is continuous and

“reasonable”“reasonable”

Colorado River AqueductColorado River Aqueduct Established 1928 to bring water to L.A. Established 1928 to bring water to L.A.

and rest of Southern Californiaand rest of Southern California First delivery in 1940; serves 15 million First delivery in 1940; serves 15 million

peoplepeople Lawsuit from Arizona (1953) finally began Lawsuit from Arizona (1953) finally began

to be implemented in 1985 - amount will to be implemented in 1985 - amount will decrease and this amount will be decrease and this amount will be replaced by State Water Project water.replaced by State Water Project water.

Five pumping stationsFive pumping stations Diversions for agricultureDiversions for agriculture

Dams and Dams and Global Global

River River DegradationDegradation

Aswan Dam, Egypt Lake NasserAswan Dam, Egypt Lake Nasser

Shasta Dam, CAShasta Dam, CA

Upstream of Dams - Negative Upstream of Dams - Negative Impact Impact

EnvironmentEnvironment Loss of terrestrial/riparian habitat Loss of terrestrial/riparian habitat

and speciesand species Creation of artificial lacustrine Creation of artificial lacustrine

(lakes) system (lakes) system exotic species introductionsexotic species introductions Reservoir/storage for Reservoir/storage for

contaminants contaminants Cultural / socialCultural / social

Loss of cultural resourcesLoss of cultural resources Displacement of families (villages, Displacement of families (villages,

regions)regions) Water quality hazardWater quality hazard

EconomicEconomic Shift in land use / economyShift in land use / economy Water loss via evaporationWater loss via evaporation Water loss via seepageWater loss via seepage

AestheticAesthetic landscape inundatedlandscape inundated

DownstreamDownstreamImpacts of DamsImpacts of Dams

Altered hydrology - no seasonalityAltered hydrology - no seasonality Altered water quality/characterAltered water quality/character Modify nutrient cyclingModify nutrient cycling Reduce sediment supplyReduce sediment supply Channel adjustmentsChannel adjustments Habitat modificationHabitat modification Species impactsSpecies impacts River fragmentationRiver fragmentation

Three Gorges DamThree Gorges Dam World's largest hydroelectric World's largest hydroelectric

dam, Three Gorges, Yangtze dam, Three Gorges, Yangtze River. River.

1.3 million people had to be 1.3 million people had to be relocated.relocated.

Cost $37 billionCost $37 billion Some claim: By shifting a Some claim: By shifting a

significant mass of significant mass of water, the dam will water, the dam will literally SLOW THE literally SLOW THE ROTATION OF THE ROTATION OF THE EARTHEARTH

WaterWater Supply, Renewal and UseSupply, Renewal and Use Too little WaterToo little Water Dams and ReservoirsDams and Reservoirs Transferring waterTransferring water

Groundwater and SaltwaterGroundwater and Saltwater EfficiencyEfficiency Too Much WaterToo Much Water

Water PollutionWater Pollution

Tapping GroundwaterTapping Groundwater

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

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

The number one removal of water The number one removal of water from aquifers is for irrigation for from aquifers is for irrigation for farmingfarming

Groundwater ProblemsGroundwater Problems

Aquifer depletion Aquifer depletion more water is removed than is more water is removed than is

naturally refreshednaturally refreshed Aquifer subsidence Aquifer subsidence

land sinks due to withdrawal of land sinks due to withdrawal of groundwater (Mexico City)groundwater (Mexico City)

Intrusion of salt water into aquifersIntrusion of salt water into aquifers Contamination from multiple sources Contamination from multiple sources

Groundwater DGroundwater Depletion epletion Aquifer Depletion Aquifer Depletion

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

Saudi Arabia, China, Saudi Arabia, China, northern Africa, northern Africa, southern Europe, southern Europe, Middle East, Thailand, Middle East, Thailand, IndiaIndia

www.npwd.org/Ogallala.htm

Aquifer Aquifer Subsidence Subsidence

Mexico City’s aquifer has Mexico City’s aquifer has shrunk enough that land shrunk enough that land has dropped up to 7.5 mhas 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 One-third of the water supply for water supply for coastal areas of coastal areas of Greater Los Angeles Greater Los Angeles comes from local comes from local ground-water ground-water sources.sources.

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

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

DesalinationDesalination Removal of salts from ocean water Removal of salts from ocean water

distillation distillation first land-based desalination plant was established first land-based desalination plant was established

in 1928 in the Netherlandsin 1928 in the Netherlands

www.oas.org/usde/publications/ Unit/oea59e/ch21.htm

Removal of salts Removal of salts from ocean water from ocean water reverse osmosis reverse osmosis

using high pressureusing high pressure

The Santa Barbara The Santa Barbara facility began facility began operation in March operation in March 1992 1992

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

DesalinationDesalinationhttp://urila.tripod.com/

WaterWater Supply, Renewal and UseSupply, Renewal and Use Too little WaterToo little Water Dams and ReservoirsDams and Reservoirs Transferring waterTransferring water Groundwater and SaltwaterGroundwater and Saltwater

EfficiencyEfficiency Too Much WaterToo Much Water

Water PollutionWater Pollution

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

& leaks& leaks

repair leaky pipes/canalsrepair leaky pipes/canals

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

water conservationwater conservation efficient toilets, faucets, & shower headsefficient toilets, faucets, & shower heads

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

Types of BenefitsTypes of Benefits

Possible benefits of canal Possible benefits of canal replacement with pipelinereplacement with pipeline::

reduction in seepage lossesreduction in seepage losses improvement of head and on-improvement of head and on-farm water deliveryfarm water delivery

better operation of distribution better operation of distribution networknetwork

reduction in maintenance costsreduction in maintenance costs

Direct Potable Water Direct Potable Water ReuseReuse

TreatmentTreatment

WastewaterDrinking Water

Direct Direct Potable Water Potable Water

ReuseReuse

Case Studies:Case Studies: Windhoek, Windhoek,

NamibiaNamibia Denver, ColoradoDenver, Colorado

Health concernsHealth concerns Public perceptionPublic perception

Windhoek, NamibiaWindhoek, Namibia

Population: Population: 220,000220,000

Severe water Severe water shortageshortage

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

Windhoek, NamibiaWindhoek, Namibia

40% of water demand returned as 40% of water demand returned as wastewaterwastewater

2,000 m2,000 m33/day of reclaimed water/day of reclaimed water Basic public acceptanceBasic public acceptance No significant epidemiological trendsNo significant epidemiological trends

Data consistent with WHO health trendsData consistent with WHO health trends

Specific Uses for Recycled Specific Uses for Recycled WaterWater

Subsurface drip irrigationSubsurface drip irrigation SaferSafer

Non-aerosolizing of water Non-aerosolizing of water and pathogensand pathogens

More prone to cloggingMore prone to clogging Requires more maintenanceRequires more maintenance

More efficientMore efficient Less evaporative water lossLess evaporative water loss Feeds roots of plants/grass Feeds roots of plants/grass

directlydirectly

• Toilet flushing

S t o r m w a t e r in t o c r e e k s ,

r i v e r s & b a y s

3 0 0 k L

7 0 k L

1 0 0 k L

W a t e r i n e f f i c i e n t W a t e r e f f i c i e n t

1 5 0 k L

3 0 0 k L

2 ,0 0 0 L

1 0 0 %

8 0 k L

1 0 0 %

S e w a g e t r e a t m e n t

p la n t

WaterWater Supply, Renewal and UseSupply, Renewal and Use Too little WaterToo little Water Dams and ReservoirsDams and Reservoirs Transferring waterTransferring water Groundwater and SaltwaterGroundwater and Saltwater EfficiencyEfficiency

Too Much WaterToo Much Water Water PollutionWater Pollution

Too Much Water: FloodsToo Much Water: FloodsToo 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: FloodsToo 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: FloodsToo 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