Why rainwater harvesting a must in India!!
In India there is always a shortage of water wherever you go — whether in a state, city or village- Millions of Indians currently lack access to clean drinking water, and the situation is only getting worse. An article states that: In 2006 between the domestic, agricultural, and industrial sectors, India used approximately 829 billion cubic meters of water every year, which is approximately the size of Lake Erie. By 2050 demand is expected to double and consequently exceed the 1.4 trillion cubic meters of supply. Groundwater is increasingly being pumped from lower and lower levels and much faster than rainfall is able to replenish it. The average groundwater recharge rates of India’s river basins is 260 m3/day. New Delhi demands 36 million cubic meters of water per day. The New Delhi Jal Board supplies just over 30 million cubic meters per day, but only 17 million cubic meters actually reach consumers due to infrastructure problems, such as leaking pipes. The government has avoided proper maintenance of pipes and canals, which is now causing major inefficiencies in water use. As New Delhi’s water supply runs through 5,600 miles of pipes, up to 40% leaks out. The Jal Board sends tankers to New Delhi with water that people have to wait in long lines to get, and what they receive is of questionable quality. Rather than fixing the pipelines, the government is falling back on these tankers, which is an expensive and inefficient method of delivering water to its citizens. Despite these weak attempts, 27% of homes in New Delhi receive tap water for less than 3 hours a day. As a result of the government’s inability to provide adequate water, private water suppliers, which charge exorbitant prices, have spring up and people have begun to dig neighborhood wells, depleting groundwater even further (Brooks, N).
Due to all this water crisis governments and engineers are busy exploring new and cost effective methods of getting water to their people. At the state and local levels, governments are standing up water ministries to defend against the effects of groundwater abuse — educating its people as to the hazards of its depletion, and paving the way for a better and water-rich India. This winding road of prevention, education, and research has led them to the sustainable and low-cost Rainwater Harvesting. Our goal is to get a method which is of low cost and is easy to built; that system is none other than Rainwater Harvesting. Every states. Cities, and villages need to have this system installed for a better India who will not have crisis of water after the installation of rainwater harvesting.
Rainwater harvesting is the process of collecting, filtering, storing, and using rainwater for consumption and irrigation. This simple system collects and stores rain water runoff from roof tops and hillsides before it gets lost in the ground (College, B). This technique is being used all around the world, as this process reduces great deal of consumption of groundwater. This system benefits all over the India especially in villages and schools where kids don’t get enough water to drink because of shortage of water in those areas. According to Baldev Chaugh, one of this colleague; whose hometown is in a small village called Arjuni (Chhattisgarh, North India), had a neighbor who used to walk 6 miles every day in search of water, leaving her school-going children unattended, before the Rainwater Harvesting system was installed at that village and now that women had more time to engage in other economic activities and taking care of her child (personal communication, September 25, 2015). Also, according to a video by a college: after installing this Rainwater harvesting process in Rajasthan (where there is most shortage of water in India as the place doesn’t get much rain) they are now able to drink water and use water for their purposes. 100 schools in Rajasthan are now able to drink water and hence more and more kids are going to study, as now they don’t have to go far away to get water . After installing this process 1300 schools in 17 states have enough water. They have collected 50 million liters which are reaching to 235,000 children (College, B). Everyone in India, Afghanistan, Ethiopia, The Gambia, Mauritian, Mali, and Senegal (places where there is most shortage of water) should have Rainwater Harvesting in every single villages and states .
According to Baldev chug, “Water Harvesters’(his company) has taken a noble initiative to execute the project at various locations in India. Though the rainwater harvesting concept has been a household name for all these years but not many people are aware of the technology used and the need to replenish the ground water levels. The Company has a specially designated team which works in coordination with different NGO’s in order to spread awareness among the masses (through campaigns, seminars and talk shows) about the importance of ground water recharging in the wake of persistent ‘water crisis’ experienced in most parts of the world including India. As a result of a modest endeavor on the part of its expert team, the Company has, since the day of its inception, successfully completed over 200 RWH projects in and around Delhi (Northern India) and the clients include various schools, colleges, residential & commercial premises, prestigious corporate houses” (personal communication, September 25, 2015).
Rooftop rainwater harvesting systems are now mandatory for new buildings in 18 of India’s 28 states and four of its seven federally-administered union territories, according to India’s Press Information Bureau (Circle of Blue). According to the Tamil Naidu’s government: The Rain Water Harvesting movement launched in 2001 was the brainchild of the Honorable Chief Minister. It has had a tremendous impact in recharging the groundwater table all over Tamil Nadu. Amendments made to Section 215 (a) of the Tamil Nadu District Municipalities Act, 1920 and Building Rules 1973, have made it mandatory to provide RWH structures in all new buildings. To consolidate the gains, various measures have been taken up for rejuvenation of RWH structures created already in both public and private buildings, besides creating new ones. IEC activities will be continued in the Town Panchayats to sensitize all the stake holders to sustain the momentum. During 2011–12, in order to give a fillip to this laudable programme, the Town Panchayats have undertaken the construction of new RWH structures and renovation of old RWH structures. IEC activities (Paragraph 5)
Rainwater harvesting sure is beneficial but it can be little expensive for people in villages but we have the solution for this financial problem too. The Circle of Blue states that: Because of falling groundwater tables and the cost of developing surface supplies, new government mandates and funding emphasize rainwater harvesting. About 50 percent of the funds for India’s rural employment act are being used for water harvesting systems, said the Minister for Rural Development to the Press Trust of India. A rule requiring all new buildings in Bangalore to incorporate water harvesting systems will be extended to all cities in Karnataka state next year, according to DNA India. The state is also considering a water bill rebate for citizens who install such systems in their houses. Rainwater harvesting would provide Bangalore’s water needs for six months of the year, said the city’s water chief at a conference on urban water development last week. Delhi’s water board has a program to provide technical support and financial incentives for residents and businesses wanting to install a system. The city’s government buildings are already required to have harvesting systems, according to the Tribune India. Its admiring that the Minister of Rural Development are using the funds to build the Rainwater systems, and it’s very good tactic about them giving water bill rebates to those who will be installing the system. The water bill rebate is a great way to ensure that more and more people install this system in their houses. People will definitely build the Rainwater system when they will know that they are provided with water bill rebate. This water bill rebate is definitely a 1 stone 2 bird theory, people will be able to save lots of water and will get money too for installing. Although, Government and minister need to find a way to monitor that everyone is taking advantage of Rainwater harvesting. Also, government should hire people who can go to villages to educate people in villages about rainwater harvesting, so that villagers can take great advantage of this technique for irrigation, and drinking purpose. If villagers understand this technique than India will have higher education rates because the children will focus more on studies and less about going to places to look for water. Now we know what rainwater harvesting is and how we can get the budget and money to build it, the next step is to know about the mechanics of the system.
Rainwater Harvesting system contains Roof Catchment, Gutters, Downpipes, storm drains, Filter chamber, and Ground water recharge structures like pit, trench, and tubewell. The rainwater that falls on the surface or roof top is guided to borewells, pits or wells through small diameter pipes to recharge the underground water which can be used later (Baldev Chugh). There are two main techniques of Rainwater Harvesting: Storage of rainwater on surface for future use, and recharge to the ground water. According to Water Harvesters (Baldev Chugh) :
Recharge to ground water is a new concept of rain water harvesting and the structures generally used are :- Pits :- Recharge pits are constructed for recharging the shallow aquifer which are back filled with boulders, gravels, coarse sand. Trenches:- These are constructed when the permeable stream is available at shallow depth. These are back filled with filter. materials. Dug wells:- Existing dug wells may be utilized as recharge structure and water should pass through filter media before putting into dug well.
Hand pumps :- The existing hand pumps may be used for recharging the shallow or deep aquifers, if the availability of water is limited. Water should pass through filter media before diverting it into hand pumps. Recharge wells :- Recharge wells are generally constructed for recharging the deeper aquifers and water is passed through filter media to avoid choking of recharge wells. Recharge Shafts :- For recharging the shallow aquifer which are located below clayey surface, recharge shafts of 0.5 to 3 m. diameter and 10 to 15 m. deep are constructed and back filled with boulders, gravels & coarse sand.
Lateral shafts with bore wells :- For recharging the upper as well as deeper aquifers lateral shafts of 1.5 to 2 m. wide & 10 to 30 m. long depending upon availability of water with one or two bore wells are constructed. The lateral shafts is back filled with boulders, gravels & coarse sand. (Para 2)
In conclusion regarding rainwater harvesting system techniques, there are many techniques and ways in which you can build a Rainwater Harvesting system in houses; for example: dug wells, hand pumps, recharge wells, pits. The only part you need to be built is the construction of tanks, every other part of this system is easily found in a house. Every house, buildings, and schools has a built in drains, gutter, and downpipes and hence the only job we need to do is getting RCC tanks with bricks which will be elaborated in following paragraphs.
Designing of rainwater harvesting system includes following process. According to Vikas Kumar Singh:
Designing of Rainwater Harvesting system includes the design of gutter, conveyance pipe and storage tank according to the designed volume of rainwater harvested. A storage tank is RCC tank which is used for collecting roof-top water. The tank, used to store water in a rainwater harvesting system, is usually its most expensive component. If we choose to make it very large, the system will make the best use of the water running off the roof but will incur a high cost. If we choose a very small tank, the system will be cheap but will waste quite a lot of the available water because the tank will sometimes overflow. So ‘sizing a tank’ means choosing the best compromise between good performance and low cost. For finding the estimation of tank size based on availability of water, we can use the water budgeting which is for the weekly average rainfall data of monsoon season in hostels and college building. The weekly demand of water for hostels was taken as 70,80,90,100 and 110 m3 and for college building it was 24 m3 (based on 451/capita/day). The water budgeting was done by deducting the weekly demand from weekly availability of water and the cumulative value of this deduction was calculated and that is how we found the minimum required size of a tank. (Singh V. K., Kumar; Santosh, D. T.)
Designing of a tank is also based on the basis of system cost, amount of rain to be collected, volume of rain and its distribution, the size of catchment area , the expected runoff water supply, area of roof, and level of external support. Last step for the design process is: Catchment area is carefully observed and then slope & availability of space around the building, the catchment area was divided into parts and the tank was constructed for each parts separated according to the harvested rainwater collected to it (Kumari R). Rainwater Harvesting system process can be done in any houses, building, or congested places because of the design of pipes and tanks as this materials are found easily in every markets and shops. Storage tanks can be expensive but if you make a small tank than it’s not worth it. It’s better to make a tank which is strong and can hold all the water. This process can be challenging but if you know the process and what data is required to build a system than you can have a rainwater harvesting system in no time.
The cost estimation to make the tank economically reasonable is by making the walls of the tank by bricks and the base to be made of RCC. The required capacity of a single tank was 366 m3 . Cost of digging of tank was estimated to be Rupees 16470 ($248), The required RCC base is 0.5 mm thick and total volume of RCC required is 60 m3, the total cost of the RCC base was estimated to be Rupees 264000 ($3990) Brick walls were assumed to be 0.23m thick and the total volume of brick walls were 30.86 m3 The total cost of the brick walls was estimated to be Rupees 60188.70 ($909) and the total cost of construction of a single tank was estimated to be Rupees 340658.70($5161). The junk value was assumed to be 0. The life of structure was assumed to be 25 years. Depreciation was Rupees 13583.08/year after 25 year. The interest was Rupees 17087.02/year @ 10 % per annum. The maintenance cost was Rupees 6813.17/year @ 2% per annum. The cost per liter of water harvested was Rupees 0.103/liter (Kumari R; Sherring A). The cost of construction of tank of size 81 m3 was Rs 1,61,683 and of size 100 m3 was Rs 1,84,607. For the estimation of cost of surface tank cost of earth work, concrete work, brick work, plastering and their respective electric, water and charges is also considered. The cost of tank of size 8 lm3 and labor charges is also considered. The cost of tank of size 81 m3 and l00 m3 is Rs 161683 and Rs 184607 respectively (Singh V. K., Kumar, A; Santosh, D. T.). After knowing design, process, and estimation of this system, you may still be wondering if there are other systems out there so you can compare and contrast two systems and chose the best among them right?
Rainwater harvesting system is been used for many years now and is the most convenient way of water conservation, but there is another method which is equally popular when it’s about water conserving. The second method which we hear a lot is greywater reuse which is equally eco-conscious just like rainwater harvesting. People usually think that rainwater harvesting and greywater reuse are same but they are totally different from each other. Rainwater harvesting is far better than greywater reuse and you will know the reason why.
Before you all understand the major difference between Rainwater harvesting & greywater reuse and why Rainwater harvesting is preferred, you all need to be familiar with the concept of greywater reuse. Bluebarrelsystems tells us that Greywater means once-used wastewater from domestic sources i.e. washing machines, bathroom sinks. I am sure you all must be wondering why Greywater doesn’t include kitchen sinks and toilets? the reason is kitchen sink water and toilets water is called blackwater (bacterial load with chemical and biological contaminants) (paragraph 4). Greywater systems must be either purified from home or it can get redistributed. Now you all understand what Greywater system is so now it’s time to know the difference between Greywater and Rainwater Harvesting
There must be some people out there who must like being able to redirect water from sinks and showers to their garden or for irrigations or for other purposes but this Greywater is not at all sanitary here is the reason why. According to Bluebarrelsystems, Greywater contains lint or hairs and soap suds hence we should not be using this system for irrigations, plantations, and plotted plants. Bluebarrelsystems also tells us that Greywater should never be stored for drinking purpose (paragraph 7) as it needs to be filtered like 10–20 times because of all the bacteria and other contaminated stuff. As its mentioned earlier, many people collect Greywater from showers and sinks but according to Bluebarrelsystems these system requires a permit in most authority and help of professional (para10). In conclusion, Greywater can be a good way to do-it-yourself water conservation but it takes up lot of effort and lot of time/money because of the permit and professional help and also because it requires lot of filtering as greywater is not free of chemicals. In compared to Greywater, rainwater is fresh precipitation coming straight from the sky, completely free of salts, bacteria, chemicals, and minerals. Rainwater is natural, pure and cleanest water and hence doesn’t require filtered much compared to Greywater. Because Rainwater is clean it can be stored for drinking purpose and for irrigation and potted plants in compared to Greywater. The major difference between rainwater and greywater is that rainwater is simple, effective, and less time consumer and rainwater comes directly from sky or water which is runoff whereas greywater is unpurified waste water from home. In the end whichever option you end up liking or believing in, Rainwater Harvesting is a perfect solution for reusing the water available to us as the system stores pure and natural water and can be used for drinking purpose too whereas greywater is only used for outside purposes (redistribute to places in your home)
Everything in this world has con and pro, just like that rainwater harvesting has some cons too. Rainwater is collected when it falls on the earth as rainfalls, which is stored and utilized at a later point but what if you don’t get rainfall at all? Rainfall is very hard to predict in India especially in places like Rajasthan where they don’t get lot of rainfalls and sometimes little or no rainfall can limit the supply of rainwater. It is not advisable to depend on rainwater alone for all your water needs in areas where there is limited rainfall. Rainwater harvesting is suitable in those areas that receive plenty of rainfall(Rinkesh Kukerja). In other words, if there isn’t much rainfall then how will one be able to save the rainwater and how will rainwater harvesting be useful to them? It may be true that rainwater harvesting will be not be advisable to places where there is not much rainfall but just because that place doesn’t get that much rainfall doesn’t mean they shouldn’t be having rainwater harvesting system in their house. It’s not like they will never get rainfall hence when they get rainfall they can use up the system to store it for later, especially if they got heavy rainfall last year then they will have lot of water stored to use it for future when they won’t have enough rainfall. They believe that the collection and storage facilities may also inflict some kind of restrictions as to how much rainwater you can use. According to them during the heavy downpour, the collection systems may not be able to hold all rainwater which ends up going to drains and rivers(Rinkesh Kukreja). In other words, if a place get a heavy rainfall than the chances are that the rainwater collection system will not be able to take all that rainwater in its storage area which will result in losing all the extra water. However, if you build a big storage tank then you won’t have problem at all about this downpour. Building a storage tank can be costly but it’s onetime fee and when you will have a big storage tank then you will be able to store more and you won’t have much problem about having a downpour.
In the end, I would like to conclude by saying Baldev’s last words which was: “Rainwater Harvesting has a bright future ahead in India and soon every state in India will have this system mandatory. Also, this system will soon be used in many places like Africa, Ethiopia, The Gambia, Mauritian, Mali, California and Senegal where there is most scarce of water.” (Baldev Chugh). All the reasons discussed in this paper is the reasons why Rainwater harvesting is a necessity in India and every single corner of India should have a mandatory for Rainwater Harvesting for better future of India. India has the power to avoid this dark future if people take action immediately: start conserving water, and begin to harvest rainwater.
Baldev Chugh, who is Registered with Central Ground Water Board, Ministry of Water Resource, Govt. of India and Active Member of International Rainwater Harvesting Alliance, Geneva. (personal communication,September 25,2015)
Brooks, N. (2007, August 1). Imminent Water Crisis in India. Retrieved October 26, 2015, from http://www.arlingtoninstitute.org/wbp/global-water-crisis/606
Chugh, Baldev, & Rainwater Harvester. A TYPICAL ROOF TOP RAINWATER HARVESTING SYSTEM comprises of: Rainwater Harvesting.
College, B. (2009, September 14). Rain Water Harvesting, India and beyond 9 min. Retrieved September 5, 2015, from https://www.youtube.com/watch?v=2jIQcKlKr_w
Govt., TN. Rain Water Harvesting. Retrieved October 26, 2015, from http://www.tn.gov.in/dtp/rainwater.htm
I India Cities Focus on Rainwater Harvesting to Provide Clean Drinking Water — Circle of Blue WaterNews. (2010, January 4). Retrieved September 12, 2015, from `http://www.circleofblue.org/waternews/2010/world/india-cities-focus-on-rainwater- harvesting-to-provide-clean-drinking-water/
Kukreja, R. (2013, June 10). Advantages and Disadvantages of Rainwater Harvesting — Conserve Energy Future. Retrieved October 11, 2015, from http://www.conserve-energy-future.com/Advantages_Disadvantages_Rainwater_Harvesting.php
Kumari, R., & Sherring, A. (2012). Planning and cost estimation of roof rainwater harvesting structure “A case study”. International Journal Of Agriculture, Environment & Biotechnology, 5(3), 225–232.
Rainwater vs. Greywater — BlueBarrel Rainwater. (2014, July 30). Retrieved October 3, 2015, from https://www.bluebarrelsystems.com/blog/rainwater-vs-greywater-can-i-do-both/
Singh, V. K., Kumar, A., & Santosh, D. T. (2011).Planning and Design of Roof water Harvesting System. International Journal Of Agriculture, Environment & Biotechnology, 4(4), 375 381.