05.12.11Alan Harris

Unintended Consequences – Hoover Dam

Drought Line at Hoover DamDrought Line at Hoover Dam is lowest in almost 50 years

Yes, I am fan of both John Stossel and the Freakanomics books. I like topics that challenge commonly accepted beliefs.  Today’s marketing and media empire spin bad ideas to make them look good, which then become the commonly accepted beliefs.

So what is actually “good”? Is it good when man conquers nature?  How far should we go and what are the unintended consequences when we tame Mother Nature?

Take Hoover Dam as an example.  Hoover Dam generates about 4 billion kilowatt-hours of hydroelectric power each year for use in Nevada, Arizona, and California – enough to serve 1.3 million people.  Hydroelectricity is a clean, renewable source of energy that does not result in air pollution, chemical runoff, or toxic waste, and is therefore beneficial to the environment. However, the construction of dams to provide hydroelectricity does affect the ecology of an area.

Hoover Dam created Lake Mead which at full pool covers 247 square miles.  Such a great body of water draws 9 million visitors a year for boating and swimming.  Most of these visitors will drive from the Las Vegas area which means 630 million miles driven using 31 million gallons of gas, plus the gas used for boats and two cycle mix for 2 stroke engines for personal water crafts, but at least the electricity created is clean.

Of course, Lake Mead provides flood control on the Colorado River.  However, in creating flood control the natural movement of sediment was impeded.  3,250 acre feet of sediment was deposited each year in Lake Mead until 1963 when another dam was built upstream.  This sediment used to flow down stream and be deposited in areas where the follow of water slowed.  End result is the erosion downstream actually increased.

Lake Mead is also a reservoir to provide water and at full pool holds enough water to cover the State of Pennsylvania to a depth of 1 foot.  However with such a large surface area about 800,000 acre-feet each year evaporates.  Since Lake Mead’s surface is thousands of times larger than the Colorado River’s surface approximately 350 billion gallons more water evaporates each year than before the dam was built.

Other environmental consequences include the change in salinity, temperature and oxygen levels all of which impact aquatic plant and animal life, but this blog focuses is on water.

Hoover Dam provided the electricity and water which made Las Vegas feasible.  As a result of the taming of nature the population exploded in Las Vegas from 25,000 people in 1950 to almost 2,000,000 people today.  A growing population has to be fed so mega farms with mega irrigation systems and mega water demands were built.  High demand combined with a 10 year drought resulted Lake Mead being at the lowest levels it has seen in almost 50 years.

So mankind tamed Mother Nature and won the battle for 75 years, but who will win the war?  Time will tell.

NOTE:  Las Vegas has done a tremendous job of recycling and reusing its water.  Most of the golf courses and fountains on the strip use reclaimed water which is good…and bad.  Water that enters the sanitary sewer system gets sent back into Lake Mead and used again. So water from toilets, showers, sinks, washing machines, etc. can get reused an unlimited number of times whereas golf course water only gets used twice, before it enters the larger water cycle.

Alan Harris

Alan Harris is a water management pioneer. With roots in landscape architecture, Alan has worked with irrigation throughout his career experimenting with hydrozones and a variety of high efficiency irrigation systems. Now, over thirty years in the landscape industry, Alan continues to stay apprised of the latest technology even in a sales leadership capacity as our National Sales Operations Support Manager and Regional Sales Leader for our landscape maintenance division.



  1. Sunday, 7:45 Richard Restuccia

    The good news about Las Vegas is because of excellent water management practices the amount of water they used in 2009 was the same amount of water used in 1999 even with the population growing by 50%.

  2. [...] I don’t care who you are, that’s funny…if you are a water geek! I had not planned for the second in the series of Unintended Water Consequences to be another dam and lake, but with the recent court ruling about water rights this one jumped to [...]

  3. Saturday, 6:34 Alan Harris

    Here is another great article with more information on Hoover Dam and the implications on energy and growth.

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