WaterWaterChapter 5Chapter 5

Part IPart I

I. Our Water ResourcesI. Our Water Resources

A. Water is a necessary resource.A. Water is a necessary resource.1. People can only survive 1. People can only survive a few a few

days days without water.without water.2. People live longer now because 2. People live longer now because

of of having clean waterhaving clean water..3. Water use in the United States:3. Water use in the United States:

a. 47 % a. 47 % agriculturalagriculturalb. 44% b. 44% industryindustryc. 9% c. 9% residentialresidential

B. Water, Water Everywhere, B. Water, Water Everywhere, but…but…

1. About 1. About 70%70% of the Earth’s surface is of the Earth’s surface is covered with water.covered with water.

2. About 97% is 2. About 97% is salt watersalt water that we that we cannot cannot drinkdrink..

3. Only 3. Only 3%3% is freshwater. is freshwater.

a. 76% is a. 76% is frozen in polar ice capsfrozen in polar ice caps

b. only a tiny bit if the earth’s b. only a tiny bit if the earth’s water is water is available for useavailable for use

= surface waters & = surface waters & ground waterground water..

C. Surface water = C. Surface water = freshwater that is freshwater that is above ground in lakes, ponds, above ground in lakes, ponds, rivers, and streamsrivers, and streams

1. All rivers are the result of 1. All rivers are the result of precipitationprecipitation

a. as a. as rain falls rain falls and and snow meltssnow melts, , water drains from water drains from mountains, mountains,

hills, hills, plateaus, and plainsplateaus, and plains. .

b. the entire area that is drained b. the entire area that is drained by by a river is a a river is a watershedwatershed..

example: the Muskingum County Watershed drains into what river?

2. Rivers of Controversy2. Rivers of Controversya. many people rely on water that a. many people rely on water that

comes from comes from another sateanother sate or or countrycountry, so , so conflicts over conflicts over waterwater are common.are common.

b. questions include:b. questions include:i. i. how much water do countries how much water do countries

upstream upstream and downstream get?and downstream get?ii. ii. Who gets to decide and regulate Who gets to decide and regulate

the the use?use?c. building c. building damsdams on the river on the river

causes more causes more problems on the river problems on the river because they because they reduce reduce water flowwater flow

d. water rights problems will d. water rights problems will get get worseworse in in the future.the future.

3. Dams = 3. Dams = structures built across a structures built across a river or river or stream stream that prevents that prevents most of most of the water the water from traveling downstreamfrom traveling downstream

a. water collects a. water collects behind the dambehind the dam to form to form a a reservoir reservoir = = an artificial lake an artificial lake (like Dillon)(like Dillon)

b. water from the reservoir is used for b. water from the reservoir is used for drinking, manufacturing,drinking, manufacturing, and and irrigationirrigation..c. can provide c. can provide flood controlflood control and and

electricityelectricityd. dams also effect ecosystems:d. dams also effect ecosystems:

i. the reservoir i. the reservoir floodsfloods dry land dry land ecosystems.ecosystems.

ii. ecosystems downstream are ii. ecosystems downstream are disrupteddisrupted because they are now because they are now dryerdryer..

D. Groundwater = D. Groundwater = water that seeps water that seeps down through the soil down through the soil and is storedand is stored undergroundunderground

1. may be stored in 1. may be stored in aquifersaquifersa. these are a. these are underground rock underground rock

formationsformations usually made of usually made of rocksrocks, , sandsand and and gravel gravel with a lot of with a lot of air air spaces spaces for water.for water.

b. occasionally may have areas b. occasionally may have areas without without rockrock

example: example: limestone caves full limestone caves full of of waterwater2. may take 2. may take millions of yearsmillions of years to collect. to collect.3. the land where groundwater comes 3. the land where groundwater comes from from is called its is called its recharge zonerecharge zone

4. Many 4. Many citiescities and and communitiescommunities use use groundwater.groundwater.

a. dig a. dig wellswells into aquifers and into aquifers and pump water pump water out.out.

b. in some places, groundwater is close to b. in some places, groundwater is close to the the surface and comes out in surface and comes out in springssprings

5. Aquifers are running 5. Aquifers are running lowlowa. people are a. people are pumping water out faster pumping water out faster

than it than it can be replacedcan be replacedb. the water level in many aquifers is b. the water level in many aquifers is

dropping dropping fastfast

E. Solutions to Groundwater E. Solutions to Groundwater ShortagesShortages

1. Desalting sea water = 1. Desalting sea water = desalinizationdesalinizationa. saltwater cannot be used for a. saltwater cannot be used for drinkingdrinking or or irrigationirrigationb. two main methods exist:b. two main methods exist:

i. i. distillationdistillation = = heat heat evaporates evaporates the water leaving the water leaving the salt behindthe salt behind

ii. ii. Reverse osmosisReverse osmosis = = pressure pressure pushes water through a semi pushes water through a semi

permeable membrane that does permeable membrane that does not allow salt throughnot allow salt throughc. desalinization is very c. desalinization is very expensiveexpensive

2. Towing water from one place to 2. Towing water from one place to anotheranother

a. towing a. towing icebergsicebergs is one possibility. is one possibility.i. i. Saudi Arabai Saudi Arabai experimented with experimented with

towing thesetowing these

ii. problems: they are ii. problems: they are hard to hard to tow; tow; they they melt quickly melt quickly as they as they

get near the equator; how get near the equator; how do do you you transport ittransport it once it gets once it gets to to shore?shore?

b. Alaska is experimenting with b. Alaska is experimenting with sending sending water south in water south in plastic plastic bags bags to to sellsell..

3. Water Conservation – some 3. Water Conservation – some examples:examples:

a. installing a. installing low-flow faucetslow-flow faucets and and shower headsshower heads

b. b. turning off tap waterturning off tap water while while brushing brushing teethteeth and and shavingshaving

c. water lawns c. water lawns at nightat night to to reduce reduce water water loss loss by by evaporationevaporation

d. people in desert areas are d. people in desert areas are replacing replacing their grasstheir grass with with native native plants plants that need that need less waterless water

e. putting e. putting filled water bottlesfilled water bottles inside inside toilet tanktoilet tank to reduce to reduce the the water used for water used for each flush.each flush.