Advantages of Rainwater Harvesting in a Modern World
Professor Renville English I 14 September 2012 The Advantages of Rainwater Harvesting in a Modern World Picture yourself on a hot summer day…is water involved? Does your damp skin feel the cooling effect of a light breeze? Maybe you’re thirsty and sipping on a glass of lemonade, ice cubes bobbing at the surface. Perhaps you are at the beach, listening to the waves crash onto the shore, or you’re in your backyard hearing the sprinklers on the lawn. Yes, water is involved. Water, in all of its forms, is one of the most essential substances on Earth and provides the opportunity for life.
We, as a society, take water for granted. Every day, if you want water, all you have to do is walk to the nearest sink and turn it on. There is no thought as to where that water comes from, or the fact that it may not be there forever. Our everyday consumption behaviors such as showering and clothes washing can have a significant impact on the environment. Imagine a future where water is scarce and restricted. How would you survive? All over the world regions with sustainable ground water balance are shrinking every day.
This can be due to depletion because of overdraft, salinization from inadequate drainage or pollution from agricultural and industrial activity. In Yemen alone, ground water extraction is expected to exceed recharge by 400 percent. Aquifers in Mexico are declining at an average rate of 1. 79 to 3. 3 meters per year (Shah, Molden, Sakthivadivel and Seckler, 2000). At such an alarming rate of recession, it is important to find another alternative source of water to help recoup some of the ground water supply.
For this reason I do believe that rainwater harvesting is a viable option to substitute ground water extraction in some regions and to help replenish ground water. About 70% of the Earth is covered with water, and 96. 5% of that is part of the oceans. Only a small portion of the Earth’s water is fresh water. 1. 7% is below ground and 1. 8% is above ground in ice caps, glaciers and permanent snow, with only . 06% usable above ground in lakes, rivers and swamps (Shah, Molden, Sakthivadivel and Seckler 2000). Rainwater harvesting can be used in many ways.
Rainwater can be used as water for livestock, irrigation for crops, to water plants around your house, to replace water for showering, flushing your toilet, for your dishwasher or for laundry, and with the right treatment, it can be used for drinking water. There are many advantages to rainwater harvesting. After the initial cost for equipment, rainwater harvesting is essentially free. It eliminates the need for intricate and expensive dispensing systems. It can replace groundwater supplies where the groundwater is unacceptable or unavailable or it can increase finite ground water supplies.
Rainwater has a nearly neutral pH and is not hard, so it eliminates the need for adding salts for softening the water and it is also sodium free. Plants thrive in rainwater (as seen when it rains). One of the most interesting aspects of rainwater harvesting is learning about the methods of capture, storage and use. The idea of rainwater harvesting is to intercept precipitation before it gets dirty. Contamination can still take place in the air, on the collection surface or in the storage facility itself. For that reason it may be more desirable to treat the water or restrict it to non-potable use (non-potable meaning not for consumption).
Boiling is resource intensive and there is the danger of accidental scalding. Chemical disinfection requires some management, but it is well understood and compatible with water storage (Thomas 1998). However, possibly the best way to treat rainwater is via a filtration system. When assessing the health risks of drinking rainwater, consider the path taken by the raindrop through a watershed into a reservoir, through water treatment and distribution systems to you, the consumer. Water absorbs contaminants and minerals on its way to the reservoir.
While in the reservoir, the water can come into contact with all kinds of materials: oil, animal wastes, chemical, pharmaceutical and industrial pollution and trash. It is the water treatment plant’s job to remove contaminants and kill pathogens, however when chlorine is used, it degrades into byproducts that may pose health risks. The raindrop harvested on site will travel down a roof by way of a gutter to a storage tank. Before it is used for drinking, it is treated by a simple process with filtration equipment that occupies about nine cubic feet of space (Krishna 2005).
Rainwater harvesting can also reduce the volume of storm water lessening the impact on erosion and decreasing the load on storm sewers. This would help to keep pollutants, such as pesticides and fertilizers, out of rivers and ground water (Krishna 2005). The summer of 2012 was harsh. Several regions suffered. Almost 61% of the country was in drought according to Brian Fuchs in an interview with USA Today posted on their website July 17, 2012. Rain was few and far between, however a lot of rainwater was wasted. Having water shipped in can be very expensive, and so many farmers cannot afford the added cost.
Harvesting rainwater for irrigation is already utilized in some regions of the world such as India where the bulk of their rainfall happens in about 100 hours of heavy downpour with little time to replenish the ground water supply (Keller, Sakthivadivel and Seckler 2000). If more farmers would utilize rainwater harvesting during the times that it does rain, and build up a back up supply, then when rain is scarce, more of their crops could be irrigated, helping to offset some of the devastation. Next year, in 2013, the prices of gas as well as groceries are expected to rise immensely because of the scarcity of crops in 2012.
It is no surprise that rainwater harvesting is utilized more in poorer countries where it is generally more difficult to get clean water; however, in the long term clean water scarcity is expected to intensify globally, even in richer countries (Thomas 1998). Systems can be as simple as a rain barrel for garden irrigation at the end of a downspout or the can be as complex as a potable (for consumption) system. It makes sense, then, that for showers and flushing the toilet, rainwater could be used to offset using water from other sources that are shrinking annually.
Only three key elements are needed for this: a collection surface, such as a roof, guttering and a storage tank large enough to moderate fluctuations in usage and rainfall (Thomas 1998). It is the third element that poses the greatest cost burden, however it may be worth it to try to help alleviate groundwater usage and eventual depletion. From a financial perspective, a system for potable use cannot compete with water supplied from a municipality; however, it is cost-competitive with the installation of a well in rural settings (Krishna 2005). An estimated 100,000 residential rainwater harvesting systems are in use in he United States (Krishna 2005). More are being installed by gardeners and homeowners seeking a sustainable, high-quality water source. Rainwater harvesting is recognized as an important water conserving measure. I am not proposing that anyone completely rely on rainwater for their household consumption. It would be very hard to rely solely on a rainwater supply. However to try to supplement some every day water usage such as shower water, toilet water or even water for laundry would greatly benefit the water supply and, in the end, the planet. Works Cited Krishna, Dr.
Hari J. “Texas Manual on Rainwater Harvesting. ” Texas Water Development Board (2005). Print. Pandey, Deep Narayan, Anil K. Gupta, and David M. Anderson “Rainwater Harvesting As an Adaptation to Climate Change. ” Current Science, Vol 85 (2003). PDF file. Shah, Tushaar, David Molden, R. Sakthivadivel and David Seckler. “The Global Groundwater Situation: Overview of Opportunities and Challenges. ” International Water Management Institute (2000). Print. Thomas, Terry. “Domestic Water Supply Using Rainwater Harvesting. ” Diss. University of Warwick (1998). Print.
