Aquifer Depletion & World Water Usage. A glance at the globe suggests an inexhaustible supply of water.

Aquifer Depletion & Aquifer Depletion & World Water UsageWorld Water Usage

A glance at the globe suggests an inexhaustible supply of water.

The World’s Water SupplyThe World’s Water Supply• However, only However, only about 3% is about 3% is fresh water. fresh water.

• Of that 3%, Of that 3%, 70% is locked 70% is locked

in glaciers in glaciers 29% is found 29% is found

underground underground in aquifersin aquifers

1% is found 1% is found in lakes, in lakes, rivers, & rivers, & streamsstreams

Source: http://www.purdue.edu/dp/envirosoft/groundwater/src/supply2.htm

Groundwater is . . .Groundwater is . . .• An important source of fresh water

(represents over 90% of the world's readily available fresh water).

• Located in aquifers -- underground layers of porous rock and soil.

• Result of rain water seeping into the ground, eventually finding its way into aquifers.

• This underground water moves very slowly and may take a long time to recharge or refill.

Groundwater

Source: http://ga.water.usgs.gov/edu/earthgwaquifer.html

People around the world use the earth’s supply People around the world use the earth’s supply of liquid fresh water for various purposes.of liquid fresh water for various purposes.

• Agriculture (42%)Agriculture (42%)

• Electricity generation Electricity generation (39%)(39%)

• Homes/offices/hotels Homes/offices/hotels (11%) (11%)

• Manufacturing and Manufacturing and mining (8%)mining (8%)

Global water use has changed over time. What does this graph tell you about water withdrawal and

consumption since 1900?

Source: http://www.unep.org/vitalwater/15.htm. For more info and graphs see UNEP website.

• The demand for water is increasing The demand for water is increasing due to:due to:

Population growth Population growth

Better technology making it easier Better technology making it easier to access waterto access water

• But, the earth’s freshwater supply is But, the earth’s freshwater supply is limited.limited.

Water & PopulationWater & Population

• The world’s The world’s population is growing population is growing at about 80 million at about 80 million people a year. people a year.

• Therefore, an Therefore, an additional 64 billion additional 64 billion cubic meters of water cubic meters of water need to be found each need to be found each year. year.

Better TechnologyBetter Technology

• People access groundwater through wells People access groundwater through wells either by hand or by diesel/electric pump.either by hand or by diesel/electric pump.

• Diesel/electric pumps allow people to Diesel/electric pumps allow people to access water much more easily than by access water much more easily than by hand.hand.

Aquifer DepletionAquifer Depletion• As the demand for water increases, deeper As the demand for water increases, deeper

wells must be dug. wells must be dug.

• Water from deeper below the earth’s surface is Water from deeper below the earth’s surface is more likely to be contaminated with naturally more likely to be contaminated with naturally occurring minerals, such as radium, because it occurring minerals, such as radium, because it has been in contact with rock formations for has been in contact with rock formations for hundreds or thousands of years and minerals hundreds or thousands of years and minerals have dissolved into the water. have dissolved into the water.

• Since aquifers recharge slowly, wells will Since aquifers recharge slowly, wells will eventually run dry. eventually run dry.

Aquifer Depletion in Aquifer Depletion in Waukesha, Wisconsin, USA, Waukesha, Wisconsin, USA,

and Sana’a, Yemenand Sana’a, Yemen

Sana’a, the capital of Yemen, is located in Sana’a, the capital of Yemen, is located in the Middle East, one of the most water-the Middle East, one of the most water-

scarce regions of the world.scarce regions of the world.

Waukesha is located near the Great Lakes, Waukesha is located near the Great Lakes, an area with abundant water resources.an area with abundant water resources.

Both regions risk losing their Both regions risk losing their supply of fresh water as their supply of fresh water as their

aquifers are depleted.aquifers are depleted.

Waukesha & Water:Waukesha & Water: A Historical ViewA Historical View

• Late 19Late 19thth century, Waukesha was a resort town century, Waukesha was a resort town known for the healing properties of its mineral-known for the healing properties of its mineral-rich water.rich water.

• Lake Michigan was polluted.Lake Michigan was polluted.• Officials in Chicago and Milwaukee looked to Officials in Chicago and Milwaukee looked to

Waukesha as a water source. Waukesha as a water source. • In one incident in 1892, the people of In one incident in 1892, the people of

Waukesha used pistols, pitchforks, and fire Waukesha used pistols, pitchforks, and fire hoses to protect their water supply from hoses to protect their water supply from speculators. speculators.

Source: Barringer, F. (2005, August 12). Growth Stirs a Battle to Draw More Water From the Great Lakes. New York Times.

Waukesha TodayWaukesha Today

• Today, Waukesha is depleting its aquifer.Today, Waukesha is depleting its aquifer.

• Its population increased 4.4% between Its population increased 4.4% between 2000 and 2005. 2000 and 2005.

• Population of city of Waukesha = 67,658. Population of city of Waukesha = 67,658.

• Population increase has led to increased Population increase has led to increased demand for water. demand for water.

WaukeshaWaukesha• Deeper and deeper wells have been dug.Deeper and deeper wells have been dug.• The current water level is more than 600 The current water level is more than 600

feet below its original level. feet below its original level. • Deeper wells = greater contamination of Deeper wells = greater contamination of

water. water. • Radium content of Waukesha’s water is Radium content of Waukesha’s water is

more than double the acceptable level set more than double the acceptable level set by the EPA in 2000. by the EPA in 2000.

• Radium exposure over a lifetime has Radium exposure over a lifetime has been linked to higher risk of cancer.been linked to higher risk of cancer.

A Solution?A Solution?

• One solution proposed by City of Waukesha One solution proposed by City of Waukesha officials is to build a pipeline to access Lake officials is to build a pipeline to access Lake Michigan water. Michigan water.

• However, a water protection plan called However, a water protection plan called “Annex 2001,” bans new diversions of water “Annex 2001,” bans new diversions of water outside the Great Lakes natural basin. outside the Great Lakes natural basin.

• Waukesha is 5 miles outside the Great Lakes Waukesha is 5 miles outside the Great Lakes basin. Therefore it cannot take water.basin. Therefore it cannot take water.

• In spite of Annex 2001, city officials hope In spite of Annex 2001, city officials hope their proposal will be approved by U.S. their proposal will be approved by U.S. and Canadian officials. and Canadian officials.

• Supporters of this proposal state that the Supporters of this proposal state that the amount of water Waukesha would take amount of water Waukesha would take would not stress the Great Lakes’ water would not stress the Great Lakes’ water supply. supply.

• Critics of Waukesha’s plan say that the problem is not that the amount of water used by Waukesha would damage the Great Lakes, but that a precedent will be set.

• States in the West, desperate for water, (AZ, NV, and CA) could look to Great Lakes as potential water source.

• Another suggested solution for Waukesha’s water supply issues is water conservation.

• A third proposed solution is to obtain water from west of Waukesha which would cost twice as much.

Waukesha Questions

• Which of these solutions do you think is Which of these solutions do you think is best? Why?best? Why?

• Can you think of some other solutions?Can you think of some other solutions?

Sana’a, YemenSana’a, Yemen• Sana’a, the capital of Yemen, is located at 7223 Sana’a, the capital of Yemen, is located at 7223

feet (2200 meters) above sea level, on a plateau feet (2200 meters) above sea level, on a plateau surrounded by several mountains. surrounded by several mountains.

• The old part of the city has been inhabited for The old part of the city has been inhabited for more than 2500 years and was designated a more than 2500 years and was designated a UNESCO World Heritage city. UNESCO World Heritage city.

• It is a generally dry place with low rainfall and It is a generally dry place with low rainfall and limited surface water (few rivers or streams).limited surface water (few rivers or streams).

• The main source of water in the region is The main source of water in the region is groundwatergroundwater.

• Yemen has one of the highest population Yemen has one of the highest population growth rates in the world at 3.6% (in growth rates in the world at 3.6% (in comparison the U.S. has a population growth comparison the U.S. has a population growth rate of 0.91%). rate of 0.91%).

• Sana’a, with a population of 1,747,627, is Sana’a, with a population of 1,747,627, is growing at an even higher rate as people move growing at an even higher rate as people move from the rural areas to the city. from the rural areas to the city.

• The population increase raises demand for The population increase raises demand for water for drinking and growing food. water for drinking and growing food.

• Yemen is one of the world’s poorest countries. Yemen is one of the world’s poorest countries.

Sana’a YemenSana’a Yemen

• 60% of the people work 60% of the people work as farmers. as farmers.

• Agriculture in the Agriculture in the Sana’a basin area Sana’a basin area accounts for 80% of accounts for 80% of water demand. water demand.

• Cultivation of qat (a Cultivation of qat (a tree that has leaves that tree that has leaves that are chewed as a are chewed as a stimulant in Yemen) stimulant in Yemen) and grapes (a cash and grapes (a cash crop) consume the crop) consume the majority of the water. majority of the water.

Urban Farming, Sana’a, Yemen, Photo credit: FAO

Better TechnologyBetter Technology

Another reason for increase in water use Another reason for increase in water use is change from traditional farming and is change from traditional farming and water management methods suitable for water management methods suitable for the region to modern farming techniques the region to modern farming techniques such as powerful water pumps which such as powerful water pumps which allow people to withdraw much more allow people to withdraw much more water.water.

Sana’a and Aquifer DepletionSana’a and Aquifer Depletion

• Sana’a’s aquifers are dropping at a rate Sana’a’s aquifers are dropping at a rate of about 20 feet per year. of about 20 feet per year.

• If this rate continues they will be If this rate continues they will be depleted by the end of decade. depleted by the end of decade.

• The groundwater is used in irrigated The groundwater is used in irrigated agriculture, industry, and households. agriculture, industry, and households.

Sana’a and Aquifer Depletion Sana’a and Aquifer Depletion ContinuedContinued

• Due to low rainfall, the groundwater does Due to low rainfall, the groundwater does not recharge at a rate that can keep up not recharge at a rate that can keep up with current demand and is therefore a with current demand and is therefore a (mostly) nonrenewable resource. (mostly) nonrenewable resource.

• In the Sana’a region farmers and the city In the Sana’a region farmers and the city are competing for water.are competing for water.

Reasons for Overuse of Reasons for Overuse of GroundwaterGroundwater

According to the United Nations According to the United Nations Environment Program (UNEP) and the Environment Program (UNEP) and the World Health Organization(WHO), the World Health Organization(WHO), the reasons for overuse of groundwater are:reasons for overuse of groundwater are:

– Unclear water rights and thus unregulated Unclear water rights and thus unregulated extraction;extraction;

– Fuel subsidies and low import duties on Fuel subsidies and low import duties on agricultural equipment;agricultural equipment;

– High returns on cash crops;High returns on cash crops;– Inefficient irrigation practices.Inefficient irrigation practices.

Response to Crisis By Government

• The Yemeni government has The Yemeni government has – prohibited the drilling of new wells without a prohibited the drilling of new wells without a

permit permit – prohibited the establishment of new prohibited the establishment of new

industries that consume large amounts of industries that consume large amounts of water. water.

• However, this has not been enough to However, this has not been enough to stop depletion of the city’s aquifers. stop depletion of the city’s aquifers.

Other Possible SolutionsOther Possible Solutions

• Some other suggested solutions are to Some other suggested solutions are to bring water from somewhere else, such bring water from somewhere else, such as coastal desalination plants, or to as coastal desalination plants, or to relocate the capital. relocate the capital.

• Some solutions suggested by Some solutions suggested by UNEP/WHO report were to reuse UNEP/WHO report were to reuse wastewater in the city and to conserve wastewater in the city and to conserve agricultural water.agricultural water.

Sana’a Questions

• Which of these solutions do you think is Which of these solutions do you think is best? Why?best? Why?

• Can you think of some other solutions?Can you think of some other solutions?

Questions for both Waukesha Questions for both Waukesha and Sana’aand Sana’a

• What are the similarities and differences What are the similarities and differences between Waukesha and Sana’a?between Waukesha and Sana’a?

• Do you think each city needs a different Do you think each city needs a different solution? Why or why not? solution? Why or why not?

• If you could create international water supply If you could create international water supply guidelines that encouraged environmental, guidelines that encouraged environmental, social, and economic sustainability what would social, and economic sustainability what would they be?they be?