Drying of the
American West
Stop and think:
Part A…
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.
Looking at the graph
of Lake Mead you can notice the water levels were low due to drought in 1950
but it declining until that point. Lake Mead was also used to fill Lake Powell
which took its water level down as well. Since then it grew once more, after
1999 when it was at 95% capacity it started to turn for the worse. In December
2004 it was only at 54% capacity. The reservoir was started just after the
Hoover was built and it was named after Elwood Mead. It took seventeen years to
completely fill Lake Mead, which started in 1916.
2. Beginning in 1964, how long did it take to capture enough
water to fill both of the large reservoirs?
It wasn’t until 1980
to 1982 that both Lake Powell and Lake Mead were back up to full capacity after
Lake Mead was used to fill Lake Powell.
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?
The two things that
controlled the water level in these two lakes were drought/usage and water
supply from the Colorado River.
Part B…
4. Compare snowpack in a watershed to a dam on a river. How are
they alike? How are they different?
When comparing
snowpack and a dam they both hold back water so it can collect on the other
side however a snowpack is not a permanent thing like a dam is, considering a
dam is built to withstand pretty much anything. A dam allow water to flow
through it and down in the river. A snowpack can’t control the water that runs
through it and can’t be permanent.
5. What effect does the El Nino Southern Oscillation (ENSO) have
on water supplies to the Colorado River Basin?
The ENSO is a natural
see-saw in oceanic sea surface temperatures and surface air pressure between
the east and west tropical Pacific Ocean. When a La Nina event happens the area
of intense rainfall is dragged back towards Australia and away from the Colorado
River causing drought while the El Nino does just the opposite which in turn is
good for us.
6. How does increasing population of sunbelt cities in the Lower
Colorado River Basin contribute to lowering reservoir levels?
The sunbelt cities
with one being Phoenix, uses up a good majority of the water supply which in
turn has a harsh effect on the Colorado River Basin and it’s supply. If these
cities keep increasing in size then they will being using too much water being
it’s hot and the reservoir will be lowered.
7. In your own words, describe what's responsible for lower
reservoir levels in the Colorado River Basin.
I believe that drought and over use of
water supplies is responsible for lower reservoir. People that don’t get that
their cities are in a drought use water to supply pools or to make their glass
greener then everyone else.
8. List at least 3 possible impacts of the decline in water
storage on the Colorado River.
3 possible impacts of
declined water storage on the Colorado River would be the plant life that
thrives off of water would be effected, shortages in both food and water would
make the population of people decline, and the wildlife in the river itself
would be affected if it continues.
Part C…
Checking in…
Describe the trend of water use in the states of Arizona,
California, Nevada, and the country of Mexico.
I think a lot of states are using more water then what they are
bring in and a lot of places borrow water from other places so that they can
live.
How does water use in the states compare to the natural flow of
the Colorado River over the same time period?
Looking at the graphs it shows that the states are using more
water than the natural flow of the Colorado River. If things don’t change then
we are going to have to face things that no one really wants.
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.
If the water levels get low than boaters can’t be playing with
their high priced toys and they won’t like that very well. Examples can be if a
lake like Lake Pleasant has a low level in water they will close it until
things change which has happened.
9. Calculate the percent increase in AZ water consumption
between the years 1906 and 2008.
There is no data for 1906 and 2008,
but the one they start off with is 1914 at 7296 and ends with 2006 at 2809571. This
is a 273675 difference.
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.
The rate we are going
I think that the Colorado River could run dry, but that’s why we have people
that know the levels so when things start getting bad they can add to the
river. We can’t control the weather even through a lot of people think they can
seeing that in Prescott the weather says it’s going to snow but I haven’t seen
any so it’s proof you can’t tell when it’s going to do anything it’s a act of
god. The people that care for these rivers are very smart and have a back up
just in case things get bad.
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?
Since the reservoir has
to meet the growing demand much like anything. It’s not lowering at a rate that’s
noticeable, so there are currently no concerns about the reservoir. In order to
know more about when or if the reservoir will be affected by this, you would
have to know how much is being used but also how much you would expect back in
between both the river and weather providing.
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 feel that the
reservoirs prevent water shortages, if it wasn’t for reservoirs I think it
would be used already. So many uncaring people and a lot of people wanting to
start their own gardens so they don’t have to pay for overpriced food.
Part D…
13. List the title of the photograph you chose and write a short
paragraph to summarize the issue it illustrates.
The photograph I
picked was the Los Padres National forest, being that a lot of places are in a
huge drought season if someone is careless or as the Yarnell fire an act of god
causes a fire. We have to use water from somewhere so we are making that place
lower and have to give back to in some way.
14. Summarize the positive outlook with which the researchers end
the article.
I believe that the
researchers just want to prepare us for what could happen if things don’t
change. There are laws that make people stop using water when there is a
drought but a lot of people just really don’t care.
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