What agricultural events led up to the Civil War? (Show of hands) -growth of crops, such as cotton that needed a lot of hands to farm and make money. This was the main type of income at the time in the South.

Where is cotton grown now? (Show of hands)

Lubbock,Texas. Does cotton need a lot of rain to grow? Yes it does. Does it rain a lot in this region of Texas? No it does not. Where does the water come from them? (Show of hands). Possibly, methods of irrigation; but from what river? Not the Rio Grande Valley, (It just isn’t that "grande"). Not from wells nor from oceans because the cotton growers do not have the money to purify the salt water (a process called desalination).

Here is where the water comes from in West Texas:

Imagine that we have sedimentary rock. Sedimentary rock, for review, is rock that forms in layers. Usually the oldest rock is on the bottom, the newer rock laid out on top. The sedimentary rock over time is lifted, folded, pressed. There are different types of sedimentary rock such as sandstone and clay. Water interacts differently with various sedimentary rock.

Layer 1 (Newest layer)
Layer 2 (Older)
Layer 3 (Oldest Layer)

Above: Layers of Sedimentary Rock

Some sedimentary rock allows water to pass through it. Which type of rock would retain water better, clay or sandstone? (Show of hands) clay.

So if layers of clay are sandwiched in between area of sandstone that over time get compressed and bent, water is retained in large amounts below the ground. Some of this water will be exposed when erosion of the upper layers occurs.

Water Retained in Different Types of Compressed Sediment Layers

Consider several layers of soil, the first and third are which sandstone, with a layer of clay inbetween. The first layer of sandstone is worn away (eroded), leaving the clay layer exposed. The clay, being able to hold water better than sandstone, becomes a kind of reservoir for water. This reservoir of water that has been formed is called an aquifer. This is what provides water for the cotton crops in Texas. Both Western Texas and Oklahoma share a large aquifer found below the ground as a major water source. However, there is a mathematical concern to consider here. Each year the average weather puts back only half of the water used in a given year by the two sites. Thus, sooner or later the water will run out. What is going to happen then?

Another example, In the Bay area of California, they receive all their water from Northern California. What if Northern California decided not to give out water anymore? What if a state claimed that they owned the aquifer in Western Texas? Who deserves the water?

A more local situation is as follows: Here in Fairfax, VA., the residents are saying that they need more water from the Potomac River. Towns in MD are arguing against them saying to use the water that they have and conserve. The main point in all this is that there are a lot of water wars going on. Everyone wants and needs water.

All of this becomes a major concern when we consider water problems in light of global change. The making of volcanoes, earthquakes, mountains etc. lead to new continents and changes in topography where one area of land may have water and another may not.

So how many people take water for granted? (Show of hands)

What would happen of you were out of electricity? What would you do? (Show of hands) -use fire, but definitely difficult.

Over break think about this question, What would you choose to lose water or electricity? If you lost one, how would you cope without having the other?

Click here to go to the Spring 1999 Page!