Resource detail

Challenge: In recent years Bangalore has seen massive increase in population and urbanization which has put a stress on the available water resources. Fresh water sources have been exploited and polluted; lakes have either been filled up or used by real estate agents to set up property. Open ponds have dried up and bore wells have had to be dug deeper due to decrees in the ground water level. There has been a decline of 5.4m in the depth of water levels in the city over the 1978-96 period.
The primary source of water is the Cauvery River which lies 100km away and at a level 500m lower than the city due to which significant amount of money is spent on pumping the water to the city. As a result of this water scarcity, agricultural productivity suffers and there is not enough water left for domestic consumption either. In fact most government schools in and around Bangalore do not have sufficient water for washing hands, for cooking and dishwashing for the mid-day meal scheme and to run toilets. Bangalore is thus not able to meet the demands for water.

Initiative: Bangalore receives substantial rainfall and is apt for employing rainwater harvesting in order to conserve water. Hindustan Coca-Cola Beverages Pvt. Ltd. along with TERI identified schools in the area where this technology could be harnessed successfully. The architectural design of the schools involved flat roofs that are ideal for carrying out rooftop rainwater harvesting. While the company agreed to bear a larger share of the investment charge, the program was implemented in partnership with schools where the latter undertook 25% of the infrastructure cost. Five branches of Kendriya Vidyalaya School were covered under the same project namely:-

• KV, Army Service Corps
• KV, CRPF Yelahanka
• KV, Hebbal
• KV, National Aerospace Labs
• KV, Indian Institute of Science

Rainwater harvesting filters called ‘Rainy,’ were used to direct rainwater flow into stainless steel screen filters in an angular motion at a specific velocity that creates a cohesive force that segregate dirt particles from clean water, flushing the former out through a drain outlet and passing the latter through a ‘clean-water outlet’ into a tank or well. These filters are made up of HDPE (high density polyethylene) and stainless steel and are corrosion free.

Figure 1. Frictionless rainwater harvesting filter

The cost benefit analysis based on the total water collected and used in the schools indicates that the total rainwater collected compared to the water bills paid by the schools amounts to a payback period of ten years.

Along with investment in technological infrastructure, an attempt has also been made to educate the students about the problem of water scarcity in their region, the need to conserve water as well as the benefits of rainwater harvesting by conducting regular awareness programs during the daily morning assemblies. The MY WATER awareness program is also operational at 13 schools in Bangalore which aims at mobilizing the youth for water conservation.

Outcome/Benefits: The total rainwater collected during 2005 at all the 5 schools amounts to 150m3. The problem of water scarcity has been solved by employing rain water harvesting successfully. Schools have become more or less self sufficient and the expenditure owing to purchase of water has decreased significantly.

Not only is the stored water used for consumption in toilets but is also used for watering the gardens and parks within the school premises during vacations. For example, water collected at KV, Hebbal is used in the boys’ toilet where approximately 450 secondary school students are estimated to use 2025 liters of water daily. The tanks in this institution have a capacity of 12,000 liters. The initiative also brings together students and teachers, providing them a platform for expressing their creativity and ideas for sustainable development. For example, in some schools, students were made to fashion simple drip irrigation systems out of waste material and they came up with the idea of a simple device called ‘Tippy Tap’ water dispensing system which slowly releases only that amount of water that may be stored in the plastic container from which it is made.

Commercially tested: Yes