Watching the River Flow

Water is important. 

That’s a pretty self explanatory statement.  Not only do we need water (at least 8 cups a day), but we are mostly water (60% of us anyway).  It’s one of the indictors we look for in new planets to see if we can use it as future real estate. It’s cornucopia of resources can provide almost everything people need to survive. Animals and plants that grow and live in water can provide food and clothing.  Caves hollowed out by water can provide shelter. The prehistoric oceans provide an area to lay the foundation of hydrocarbons. Water can be drunk to satiate thirst.  The movement of water can power the machines of mankind.

Irrigated
Creative Commons License photo credit: kevin dooley

Man has always known he needs water. Water has always been present whether it comes freely from the skies or washes down in all its fury in a flood.  Agriculture brought about man’s first attempt to channel what water he had.  The landscape was literally remade to get the water to move where it was needed.  Deserts have been made to flower and flowering areas have been made into deserts.  As time went by, we were able to make the movement of water do more for us.  First it was used to help run simple machines, such as mills, where grain was ground into flour.  It was also used in mining, to bring the ore out of the mine, or used to power hammers at a forge.

Water power helped to start the next stage of technological development, the Industrial Revolution. Larger and larger factories were built on rivers to take advantage of the free energy that the flowing water offered them.  Unfortunately they also let the water carry off their excess and trash, making downstream a place to avoid.  While the Thames helped England become a technologic and mercantile titan, it also made the river undrinkable and became so foul that the House of Commons had to be abandoned for a while in the mid 19th century. Water was also the crucial part of steam power that allowed the transportation industry to remake itself from horse drawn carriages to trains and steamboats.

Blast off
Creative Commons License photo credit: fairlightworks

Water is still vital today.

 Most of electricity comes from burning fuels to create steam to move turbines.  Water is also crucially important for solar panels.  Water may sound like an odd thing for solar power to depend upon, but large scale solar thermal arrays can use twice as much water per mega watt hour as a coal fired plant.  Geothermal power plants use water the exact same way as coal fired plants; they heat it into steam and have it turn turbines (although the water could be replaced with other substances). Biomass needs water to grow. 

And of course water is the essential part of hydropower.  Without water (hydro) hydropower would be impossible.  When most people think of hydropower they think of dams (this is where being fond of puns can get you into a lot of trouble, kids. Just leave those dam puns alone).  A dam works by controlling the flow of the water.  It constricts the area the water is trying to move through and uses that movement to turn the turbines.  Because the pathway is constricted, the water backs up and can form a lake (also called a reservoir).  This changes the local environment from a river to a lake. This can affect the local wildlife and lead to erosion downstream.  People (and history) can be affected by dam building as well.  Due to the building of the Aswan Dam in Egypt, over 150,000 people had to be relocated because they were in the flood plain created by the dam.  The Abu Simbel Temple was moved to higher ground as well.

Hydropower can also be generated by the flow of a river, the movement of the waves, and the tides (movement is electricity) and electricity is movement. It is also easy to transfer excess electrical generation into storage by pumping some of the water back upstream or back into the reservoir. 

Electricity generated by hydropower accounted for nearly 7 % of our total U.S. electrical generation in 2010. Over half of the hydroelectricity comes from the 3 states on the West Cost; California, Oregon, and Washington.  While there has been a lot of development over the years, there is still the potential to add more hydroelectric sites and increase the electrical output by a 3rd.  However, the amount of electricity produced by hydroelectric generation varies from year to year with the water cycle.  If you have a year with less precipitation, the rivers may have less water; if the river slows, the amount of electricity is less. Most areas where a large scale hydroelectric plant would work have already been dammed up for use.  The future might be in small scale generators that would help communities near running water.

Dam1
Creative Commons License photo credit: Perrimoon

All that to say water is, in fact, important. 

We have to have it to live.  We have to have it for our energy production. It takes 10 gallons of water to make 1,000 kilowatt hours using natural gas as a fuel, up to 9,200 gallons for solar thermal and about 20,000 gallons for nuclear. So what happens when we start to run out of it?  I don’t mean that the water on the Earth will suddenly disappear.  It is in a mostly closed system and the water can’t go anywhere (except if water is used on a space ship outside the atmosphere).  What I mean is that on a planet that’s mostly water, only 3% of it is fresh water.  We can’t drink saltwater.  We can’t grow crops with saltwater.  In the coming decades we will have to manage what water we have well. There are ways to generate more fresh water.  Desalinization removes the salt from sea water, but it is energy intensive.  In some areas the excess removal of groundwater can cause subsidence.  This has been an issue in the Houston area. In the 70’s this led to the creation of a Harris Galveston Subsidence District, the only one of its kind in the USA, to monitor and regulate groundwater usage to prevent subsidence. 

Water management will become increasingly important. 

Good water management will make sure that both people and industries get the water they need. Communities all along waterways will have to work together to mange their resource.  Managed from the local level up we’ll be able to sail through any water crisis.

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