Water Usage and Reservoirs

The Swamp Stomp

Volume 19, Issue 5

Water is the single most important chemical required for life on Earth. Animals and plants are both dependent on it and can only survive a matter of days without it. There are many theories as to how water appeared on our planet. It could have come from space as part of the original nebula of gases expanding out after the big bang, possibly from comets and asteroids colliding with our planet, or maybe it was always here and was released from the ground as our planet cooled enough to retain the water. Perhaps, it was a combination of many factors. Whatever the original source, the Earth’s water supply is now essentially constant, with no new water being made or destroyed, just recirculated as part of the hydrologic cycle.

As the population of the world continues growing exponentially, the demand for water for humans, agriculture, and industry is also growing exponentially. Building dams has often been the answer when people need more water. However, the impact of dams on the water supply is unsustainable.

The history of population growth in Las Vegas is a perfect example. Many decades ago the city was growing tremendously and the population was expected to reach 400,000 by the year 2000, so a pipeline was built to Lake Mead above the Hoover Dam in Nevada. This, in turn, created a false sense of abundance of water and the population grew almost four times higher than what was predicted.

Dams give communities a false sense of security because they cover up the natural phenomena of droughts that often occur in the heat of the summer. People don’t feel the impact of the droughts, so their water usage remains constant, rather than considering rationing. In a similar way, the city of New Orleans was built behind a levee. While the levee can sustain small floods, it could not hold off a large storm like Katrina. The city was built on a floodplain and the levees created a false sense of protection from floods.

The US began constructing dams after World War II and construction in the US reached its peak during the 1960s.  Currently, though, the rate for decommissioning dams now exceeds the rate of new dam construction.

A previous article in the Swamp Stomp mentioned some of the drawbacks of building dams on rivers, such as the effects on water quality, and increased contamination, but a “dam-building boom” is happening in developing countries today. Western funding agencies are pushing the construction of dams in underdeveloped countries although the social and environmental impacts may outweigh the benefits.

Building dams in the Middle East has caused disastrous shortages downriver in many countries. Dams on the Euphrates River in Turkey have cause water shortages in Iraq and Syria. Dams on the Colorado River impact downstream cities in Mexico, leaving a dry riverbed in some cases.  Many years, the Colorado never even reaches the ocean. The cause and effect of such impacts are obvious. People in wealthy countries don’t envision the repercussions of their actions on others that are outside their realm of thought.

Climate change is also affecting the Earth’s water supply.  Rising sea levels could mean that saltwater could intrude into groundwater and our drinking supplies, especially in low-lying coastal areas, making the water undrinkable. Flooding due to extreme rainfall would cause sewers to overflow, also contaminating our fresh drinking water resources. These are just a few of the effects of climate change on our water supply.

The irony is that with 70% of the Earth covered in water, there really is no shortage of water. The problem is that 97% of it is salt water, and of the 3% that is freshwater, 2% is locked up in glaciers and in the polar ice caps.

The alternative seems simple enough: conserve water. Water saved by installing water-efficient fixtures and appliances in the home and in industry can reduce water use by 20%.  Just finding and repairing leaks in homes and in municipal distribution systems, could increase the water supply by 900 billion gallons a year, equivalent to the annual consumption for 11 million homes.

One example of how conservation can help can be seen in the cities of Phoenix, Los Angeles, San Diego, and Albuquerque. They would not be able to sustain their increasing populations without current reservoirs, however, due to conservation measures; the usage of water in the Southwest has remained flat since the 1980s, regardless of the rising populations.

Besides conservation, another method for easing water shortages is to capture and retain more rainwater. Captured rainwater is a great source of clean water that can be used for many things like watering lawns and gardens, washing, and toilet flushing, not to mention drinking water.

Seventy percent of freshwater used globally is used for irrigation. This usage that can have a tremendous impact on our water supply especially since it has been shown that half of the water used in irrigation doesn’t even get to the crops. Newer sprinkler and drip-irrigation technology uses much less water and reduces the “non-beneficial” consumption by 54% and 76% respectively.

Dams and reservoirs are not a bad solution, but the social, environmental, and economic costs and benefits should be evaluated for their long-term effects. As the population continues to rise, global warming will continue to impact our water cycle, and dams will continue to be built. There really is no one solution to this problem but unless people take a more active role in conservation and invest themselves in protecting the world’s water supply, some day, the faucets may just run dry.

1. Gies, Erica, “Do Dams Increase Water Use?,” Scientific American, Feb. 18, 2019, https://www.scientificamerican.com/article/do-dams-increase-water-use/

2. Nicklow, John W., Water Encyclopedia. http://www.waterencyclopedia.com/Da-En/Dams.html

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