Let's Get Musscular!
Photo from http://www.mnhs.org/
Elk River Dam 1920
Photo from https://www.mnopedia.org/thing/coon-rapids-hydroelectric-dam
Coon Rapids Dam 1920
Dams have been built since around 2950 B.C, and have majorly taken off since becoming introduced to the Americas in the 17th century. Un-touched rivers allow sediments, nutrients, and native organisms to freely flow through, and interact with their ecosystems as they were meant to. When a dam is added to this equation however, it cuts these flows in half, slowing the movements of these factors, throwing off the environment's natural balances. The sediments that usually move through these streams are stuck at the bottom, disturbing the usual habitats of freshwater mussels. The water also gets warmed and changes its patterns, evermore adding to the unnecessary changes in mussel habitat. Water quality decreases, and even more unwanted results come into play. Most importantly however, host fish are blocked from travelling downstream, limiting the native bivalves from reproducing and spreading genetic diversity throughout populations. Where did these dams start in America, and how did that grow into where we are now?
Dam Timeline
17th Century
19th Century
20th Century
21st Century
We start our journey in what is now Scituate, Massachusetts in the year 1640, where the first ever dam was built in America, setting off the boom of dams throughout the country. Unknowing to the settlers at the time, this one build would lead to the building of on average of one dam every day in the 21st century. When settlers arrived in the New World, they first built a church, and then a dam. This dam was their livelihood, as it provided them with the power to turn gears for all their living needs, from harvesting and processing food to building structures. Dams became so important to the settlers, that they were targeted for attack during King Phillip's War in the year 1676.
As time progressed, and we move into the 19th century, flour production skyrocketed. Now what was used to power all of this flour milling? Why dams of course! These dams held the rivers used for production of a vast variety of goods, but some also held as beautiful historical structures and parts of town identities. Although raising in numbers and use, nothing beat the impact of the 20th century.
Getting to the end of our tour of the past, we land in the 20th century, where between the years 1920 and 1950 alone, 10,000 new dams were built. By the year 1980, that number raised to 50,000 new dams in the century. With these dams, some like the Hoover Dam, which is taller than any building in San Francisco, or the Grand Coulee Dam that holds enough concrete to cover Manhattan, came new excessive wants and uses. Although these dams can create incredibly large amounts of energy, most are actually used for other jobs such as controlling floods and irrigation use, with one-third of all dams in America only being used for recreational purposes.
Now ending our tour of the past, we finish in the 21st century. Of the 3 million miles of rivers and streams residing in our country, a great majority of them are trapped into between 80,000 to one million dams. Although these numbers seem ever growing however, environmental activists have been pushing for and succeeding with the removal of several many dams since the turn of the century.
So what does our present day status mean?
Sources:
Lieb, Anna. “The Undamming of America.” PBS, Public Broadcasting Service, 12 Aug. 2015, https://www.pbs.org/wgbh/nova/article/dam-removals/.
Winzenread, Stephen Michael. Cahistory, https://watershed.ucdavis.edu/shed/lund/dams/Dam_History_Page/History.htm#:~:text=The%20first%20constructed%20dams%20were,first%20known%20dam%20to%20exist.
