What does a Non-resident think about her Rain-water harvesting theme park visit and what learning does she take from here?

As our guide opens one of the sump tanks to show what’s inside it, all of us present moved towards it slowly in curiosity with 8th standard students giggling, whispering and struggling to find their way to come forward. To maintain the decorum and bring student’s attention back our guide asks them to remain 1 feet away otherwise somebody might fall into it. He asks what do you think what’s inside? There is nothing ‘it’s water only’ and that caused us to burst into laughter.

As I enter the Rainwater Harvesting Theme Park I see a small standing statue of M.Visvesvaraya under the wide punched sky telling the story of the legacy he left behind. This park innovatively amalgamates technology to exhibit live rain-water harvesting models, structure and their functioning. These simulation models allowed all of us to understand the nitty-gritty that goes into the installation, costing and functioning of the system. It allowed us to engage with real things in an experiential way. There were two sections to the park, one is an open space where RWH systems, recharge wells, sump tanks and traditional method of RWH (Which looked to me as some magical pond reflecting the sky and a small tree that reminded me of Fairy Tales) and water wise gardening is exhibited, the other section enclosed by a roof has three galleries namely Water Gallery, Sewerage Gallery and the Centralized Gallery. The entire Gallery is a knowledge hub and the simulation model installed there adds fun to the learning process as we ourselves engage and interact to ponder over some of the critical questions.

Magical Pond?

We started our tour at 11:30 along with 8th standard students who also accompanied us to make sense of the bookish knowledge disseminated inside their 4-walled classrooms. Our Guide, Mr. Nikhilesh patiently makes us familiar with all the installations, types and structures exhibited there. As all the students take out their diaries to jot down all the key points we also start making notes but in our virtual diaries i.e our phones. A small tangent here experts say that writing down with your own hands increases your memory and retention power. As we continue with our tour, to bring back the attention of the 8th standard batch our guide addressing the students says, I will ask questions to check whether you are able to follow. This hit me with a thought that we are at a position where we are on our own, accountable to our own selves and nobody else

Banglore, silicon valley of India is also known for its gardens, man-made tanks and people who take pride in the city’s heritage and what it serves. In the midst of the busy city, crowded metros, places like rain water harvesting theme parks and other parks bring in the calmness even if it's sporadic. The rapid urbanization and increased population is adding pressure on all the limited sources that we have. Post 1980’s the trend of digging borewells started which eventually resulted in water deficit i.e the extraction of groundwater was in excess than the recharge of the aquifers. Not only was the quantity affected but the quality also deteriorated in some pockets where industries were popping up. Rainwater Harvesting is a simple and traditional practice of harvesting the rainwater that assists in recharging the groundwater and acts as a derisking mechanism. It can build resilient communities as the competition for the resources with increased population becomes more fierce. When we say innovative ways we don’t have to invariably think about technological changes as Mr. Avinash Krishnamurthy aptly puts it: “Technology is taking science out of our lives, and we must understand that Sustainability is Science”. This highlights the significance of Nature based solutions and simple techniques like RWH that can be implemented easily.

Virtual Tour of RWH Theme Park

Every house will have a roof having a small gradient from where all the water will go to the downward pipe i.e catchment area. The three basic components of RWH are catchment, conveyance and storage. Conveyance is the pipe which conveys the water to the filtration unit. There are two types of filter: one is a wall mounted filter and another another one is a centralized filter. You can either utilize this water or let it recharge the groundwater. Wall mounted filter is better for small houses. While collecting water in the wall mounted filter the principle of first flush should be taken care of which means the first 5-10 mins of rainfall should not be collected as it contains more impurities and contaminants. The water in the wall mounted filter will filter the rainwater from physical impurities and not from chemical impurities. After the water is filtered it can be stored in a tank called a sump tank. The stored water can be used for secondary purposes other than drinking and cooking.

In big buildings like vidhana soudha, HC wall mounted filters are not feasible. For large buildings the alternative is a centralized filter. In any filter there are two chambers. First one is the first flush chamber which is designed according to the volume. Second chamber has the sand bed filter; it will filter both chemical and physical impurities. Once the sump fills up to its brim, water will overflow and will recharge the wells and percolate down into the groundwater.

These recharge wells are 25 feet deep. In residential buildings minimum depth should be 10 feet because we will have a foundation that go upto 6 to 7 feet deep. In order to bypass that foundation it’s better that we go 10 to 15 feet deep. Covering it with 40 mm aggregate will prevent the silting because if silting happens it will lose its previousness.

V wire technology is not advisable. In a Strata there is a rock which you can’t recharge, a borewell is drilled to bypass the rock strata and on top of it you will have filter media and a feeding channel, overflow water will come here and the water will be directly injected into your aquifers. It is not advisable because of easy contamination of the groundwater and considered as the unscientific way of Groundwater recharge.

Stormwater Drain

Water Wise Gardening

It was indeed a meaningful and a valuable experience. Theme parks like these are an innovative way that assist in wide outreach to the citizens. Combining it with the mandatory legislation allows citizens to understand the need and potential of RWH in sustainable management of the Groundwater. Though in physical terms we are talking about something that is beneath the ground, its sustainable management and care would result not only in the availability of enough water but it will also provide avenues to stride up the ladder to make Bangalore a more progressive city.