Part A: Reservoirs on the Colorado River.

Stop and Think

1.      Consider what the "squiggly lines" on the graphs of page 2 in the "How Low Can it Go?" article really mean... Use the graph of Lake Mead levels to describe a brief history of the reservoir. Tell when and how the reservoir got started, how long it took to fill, and mention events that affected its level.

The squiggly lines on the graph on page 2 represent how much water the lake had in it at that given time.  It calculates how close to being full it was.  They are able to track the effects of the drought through these graphs and measurements.  The Lake Mead reservoir was built for many reasons; the main reason was for providing water supply.  It appears to have been built in 1937.  It was low in the 1950’s due to a drought and in 1967 it was low due to the filling of Lake Powell. 

It steadily declined from 2000-2004 due to a multi-year drought. 

    2. Beginning in 1964, how long did it take to capture enough water to fill both of the large    reservoirs?

 

From the graph it appears that it took approximately 19-20 years before both reservoirs were filled to their capacity.  

3. The levels of Lake Powell and Lake Mead both show steep declines in the past decade. What are the two things that control the level of a reservoir?

Two things that control the level of the reservoir are how much precipitation we receive and the demand that the population is requiring to provide enough water to everyone. 

4. Compare snowpack in a watershed to a dam on a river. How are they alike? How are they different?

A watershed is similar to a basin where all the water drains from precipitation and collects in that area.  I believe the difference between the two is that a watershed collects surface water where a dam collects underground water.

5. What effect does the El Nino Southern Oscillation (ENSO) have on water supplies to the Colorado River Basin?

ENSO has a modest effect on the water supply to the Colorado River Basin unless it is during a strong El Nino event.

6. How does increasing population of sunbelt cities in the Lower Colorado River Basin contribute to lowering reservoir levels?

The Colorado River provides water and electricity for most of the Southwest.  Large cities include Los Angeles, Phoenix, Tucson, Las Vegas, Denver and Albuquerque.  As these cities continue to grow the demand on the Colorado River increased causing lower reservoir levels.  

7. In your own words, describe what's responsible for lower reservoir levels in the Colorado River Basin.

I feel that the reservoir is lowering in the Colorado River Basin because many of the cities it supplies to have become “top spots” to live.  As people flood to these areas the demand is just too much for it to continue.  Our lifestyles today also use more water- people in dry cities want green lawns and that takes a lot of water to keep up.  I also think our weather affects it.  This year has been very dry for us and we have had very little rain and even less snow.  I have been waiting for our last storm of the winter season, but, the way things are going I am not sure we are going to have it.

8. List at least 3 possible impacts of the decline in water storage on the Colorado River.

Water being used exceeds the water coming in.

Drier weather.

Increased population equals higher demand.  

9. Calculate the percent increase in AZ water consumption between the years 1906 and 2008.

There is no data for 1906 or 2008.  Calculating the data provided beginning at the year 1914 and ending at 2005 I found an increase of 33185%.

10. Based on the data in this section, describe what do you think will happen if the consumption of Colorado River Water continues to grow at its present rate. Have we reached the carrying capacity of the watershed? Explain your reasoning.

I think that if we continue to use water the way we are using it the Colorado River will dry out and there will be no water to supply people.  It will be like the Great Depression but, with water.  I believe that we have reached the capacity of the watershed because at this time they aren’t even close to being full.  

11. Given that long term changes in climate are reducing inflows into the reservoir, and that outflows through Hoover Dam are growing to meet demand by an increasing population, what is the projected result in the reservoir? What would you need to know in order to predict the date of the result?

I think that eventually the dam will not hold any water because as it comes in it will be going right out.  In order to predict this outcome you would need to now demand and supply.

12. Based on data you examined in this lesson as well as other sources, do you think that reservoirs in arid lands prevent or merely postpone water shortages?

I think at one time with the demand and the population was lower it prevented water shortages.  Now that the demand is so high I think it is just a matter of time until we suffer from a water shortage.  

13. List the title of the photograph you chose and write a short paragraph to summarize the issue it illustrates.

I did not see the name of the print I picked.  I looked through all the prints and the first one stood out to me.  It is a photo taken by Vincent Laforet of a helitanker dumping water on a hot spot in the Zaca fire.  This fire took place in 2007 and scorched over 240,000 acres.  This picture stood out to me because I used to be a hotshot and this is a familiar site.  This also stood out to me because during times of drought there is a lot of precious water being used to save our land.  I feel this picture represents yet another way that the demand is greater than the supply.

 14. Summarize the positive outlook with which the researchers end the article.

I think the positive outlook that the researchers of this article give are that with knowledge and an idea of what to expect with our water situation that we can be prepared.  Cities have already implemented laws to save water.  With the data that they gather they would be able to set up some sort of water usage schedule. 

Checking In

• Describe the trend of water use in the states of Arizona, California, Nevada, and the country of Mexico.

Due to population and lifestyles all of these places are using more water than they are bringing in.  Many states have implemented water laws. California has been known to borrow water from other states. 

• How does water use in the states compare to the natural flow of the Colorado River (see graph in Part B) over the same time period?

The graph continues to show that our usage is much higher than the natural flow of the Colorado River.  Changes will need to be put into place if we don’t want to have a water shortage.

• How might the change in water levels affect you as a recreational boater? Give a specific example, naming features that are labeled in the pair of images.

Water levels affect recreational boaters because you would have limited area to take your boat due to low water levels.  Low water levels are a threat to the propellers and would do damage to the bottom of the boat.  Recreational boaters would also not be able to water ski in shallow water.