I’ll admit that I sometimes watch videos on YouTube.  Mostly I watch woodworking videos, but sometimes I watch videos of things like, music, science experiments, math tricks, and lately I’ve discovered a bunch of videos on dam removal.

These are so cool – heavy machinery moving rocks and dirt and even an explosion or two.  What more could you want in a video?  Seriously, way more exciting than watching some guy cutting wood into small bits and then gluing them back together.

Now, most of you are likely thinking this is just more evidence that my mind is slowly returning to its ten-year old self, but there is a real reason why I’ve watched a dam being demolished.  The reason?

Research for my novel.

You see I decided to research water development in California for the book.  My novel takes place along the central coast of California – a semi arid grassland.  But with the magic of modern water infrastructure there are cities, farms and a growing wine industry.  Since my book takes place in the future I wondered what that water resources would be available to rebuild society after the collapse of America.

To brush up on my knowledge of water development in California I read the book, “Cadillac Desert,” by Marc Reisner.  Originally written in 1986, it does a good job with the history of water development in the American west.  The core of most western development is based on building dams to store water for farm irrigation and for cities.  Without the dams, reservoirs, river diversions, aqueducts, cannals, pipes, pumps, most of land west of the 100th parallel, would be un-farmable and few cities would survive.

Most of our dams were built in the golden age of dam building from the 1920s to the 1970s when America built somewhere around 75,000 dams. I was interested to know what is the lifetime of a dam.  That question is important to a people who will be alive some 200 years from now.  There are a number of factors that go into calculating the lifespan of a dam and a big one is how fast the reservoirs behind the dam fills with sediments and becomes unusable for water storage.  Turns out most dams silt up and become unusable between 50 and 150 years after they are built.  There are exceptions, but most will end up like the San Clemente Dam on the Carmel River – filled with mud rather than water.

San Clemente dam was built in 1921 with 1,425 acre-feet of storage (enough for 5,000 household for one year).  By the end of the 2008 silting in the reservoir reduced storage to about 70 acre-feet, rendering the dam useless.  Around the same time they discovered that the dam was likely to fail in an earthquake. The cost to retrofit and remove the sediment was prohibitive (it would take something like 250,000 truck loads to remove the silt) so the dam was removed and the river restored.  The positive effects were the removal of a dangerous dam and the environmental restoration of the river with an expected increase in fish and other wildlife.   The dam was never used to generate power or for flood control.  The water from the river is still being delivered to homes in other ways – mostly from ground water wells fed by the river.

So, for the purposes of my novel, let me make a few assumptions:

1. The area’s population will fall.
2. The attitude of dams being bad and a symbol of failure will grow.
3. Due to falling population and the disappearance of a viable government, the dams will not be maintained and will fall into disrepair.
4. The silting process will go unchecked.

With all that, it’s likely that my new city that springs up out of the ruins of California will have to deal with the problem of getting reliable water supplies for it’s farms and cities.  Current reservoirs won’t be available to them. In fiction I can build any number of ways to get these people water – ground water, recycling, desalination and even condensing directly from the air.

But what really got me going on all this research was a thought I had the other day while I was out walking by the creek near my office.  Along that creek are a series of small dams that divert water to percolation ponds that recharge the local aquifer, where my city gets its drinking water.  I was musing that after the collapse, a group of people could possibly use these little dammed up areas as a source of water.

Then I decided to take an opposite view – what if a person was left who perhaps had been driven a little crazy by the tragic events of the fall of America.  That person might decide that destruction was more emotionally satisfying and might decide to destroy a dam.  The question then was, could one man, or perhaps a small group of people working with hand tools remove a dam on a river?

Which naturally sent me to Google to look it up.  Which led me to watch a few videos on dam removal.  Which led me to …

The dam stretched across the mouth of the canyon rising to the sky while the waters of the reservoir glistened in the late afternoon sun.  Near the middle of the dam a man is swinging a sledgehammer and throwing chunks of concrete into a wheelbarrow.  A small channel is forming across the structure.  The man, his family killed in the dying throes of America, is taking out his grief against a symbol of the civilization that failed him.

Till next week,
Andrew