Who owns Bangalore's rainwater?

Who owns Bangalore's rainwater?

We owe it to ourselves to harvest the rain to recharge the groundwater table, if we want to keep the bore wells brimming and our rivers alive, writes Malvika Tegta as she tracks the water conservation success story of a layout on Sarjapur road that makes every drop count

Malvika Tegta



It is monsoon time again. The time when the city brims with the problems of storm water drain management. Step one in tackling this issue is for each one of us to understand that it can be dealt with at the household level. Rainwater management, through simple and affordable rainwater harvesting (RWH) solutions, can not only take care of runoff but also capitalise on the substantial amount of rain Bangalore catches, in order to recharge its groundwater. Given that large parts of the city survive on groundwater and the rivers themselves depend on groundwater to stay alive, we owe it to ourselves to replenish the water table we draw from. It might help to know that one of the main reasons the city's former water source, Arkavathy, dried up, was over-exploitation of groundwater that had kept the river's base flow alive.
Consider this. Bangalore's water demand is 1,500 MLD (million litres per day) as against the current supply, 910 MLD. This shortage is made good by bore wells dug through the length and breadth of the city or by sponging groundwater resources of nearby villages. In the absence of comprehensive data, a guesstimate by Rainwater Club, an organisation that works on RWH solutions, a huge 40% of the city relies on tanker water from bore wells. "This is evident from the thriving water market and the number of water purifiers available to remedy the often bad quality of bore well water," says Avinash Krishnamurthy, executive director, Biome Environmental Solutions Pvt Ltd, the private avatar of Rainwater Club.
A 2007 study by the Institute of Social and Economic Change puts the number of these bore wells at somewhere between 2-4 lakhs, with no agency monitoring the amount of water they pull out. In the absence of groundwater recharge, many bore wells either dry out or have to go deeper for more water. "But as we dig deeper, the rule of thumb says that the amount of Total Dissolved Solids (TDS) go up, causing the water quality to deteriorate," says Krishnamurthy.
What is then keeping a city that receives an average of 3,000 MLD rainfall - double the daily demand - over 60 rainy days (a meteorological department report that looks at the rainfall pattern of Bangalore over the past 30 years) from RWH?
There are the obvious reasons: A bill for groundwater regulation that is yet to become a law; poor implementation of building laws that call for mandatory investment in RWH and lack of individual initiative among others. And then there is the multiplicity of agencies. RWH is an integrated approach as it aids storm water management. To ensure that the rain does not contaminate the groundwater by mixing up with wastes in the catchment areas, waste management is key to the process. "In Karnataka, though, groundwater comes under the department of mining and geology, water supply comes under BWSSB, storm water under BBMP and the lakes under the Lake Development Authority. So there is no one body for integrated implementation," says Krishnamurthy.
"Fortunately, RWH need not be done at the central level, necessarily. Question is, if the citizens want to be a part of the problem or the solution," asks S Vishwanath of Rainwater Club. Here are a few lessons to take away from a success story his organisation helped residents of Rainbow Drive layout execute.

Back to where it came from
When the new residents of Rainbow Drive on Sarjapur road started moving into the layout with notions of plenty ten years ago, they probably spared little thought to the water equation they were dealt with. Being on the city's periphery, they were not under the BWSSB wing and were comfortable with six bore wells at their disposal. As the number of families went up on the 34-acre layout that houses 350 plots, four of the six water sources dried up, partly on account of indiscriminate usage. Despite two bore wells left to serve two halves of the layout, the wasteful did not cross over to the conservationist.
Exasperated with the lack of initiative, one of the residents, Jayawanth Bharadwaj, stepped up. "Five years ago, the residents got serious and stopped private bore wells," he says. In end 2007, Bharadwaj mapped the consumption pattern, tracking down those who were consuming unusually high amounts of water. "It turned out that 60 people were using up 50% of the water being pumped," he says.
The reason, he soon discovered, was the price that only reflected the cost of pumping the water. So, he proposed moving to another tariff plan that reflected the 'real' cost of water. But first, the resistance had to be explained away. For that, Bharadwaj went door to door making the residents understand that the new tariffs were based on, apart from the maintenance cost of the bore wells and the pumping cost, the operating cost of the Sewage Treatment Plant (STP) "because the high users of water were also the ones who were loading the STP more ". "The moment we added sewage treatment cost, we realised we were unduly subsidising water."
The next logical move was pushing for groundwater recharge, if the two remaining bore wells — their only water source - were to remain. So he advocated construction of recharge wells in houses, "a minor investment when compared to the cost of constructing a house". Out of the maintenance cost, they dug another 20 community recharge wells across the layout.
The tariff plan the layout subsequently implemented had inbuilt incentives for the mindful and penalty for the wasteful. It starts at Rs10 for the first 10 kilolitres and grows more than proportionately to Rs60 for 40 kilolitres and above. Plus, whoever digs a well gets a discount of Rs100 per month. There are currently 60 recharge wells in the layout, that Bharadwaj considers a "pathetic number". Bharadwaj shows us his basic RWH system that involves two 2,000 litre-each tanks, the overflow from which can either be diverted to the sump or invariably goes into the 3 feet by 20 feet recharge well. "That's where we give it back to where it came from," he says. The family next door, due to lack of space in its main compound has punctuated their storm water pipe with a well that catches the running water.
The gains have been substantial, if not as big as Bharadwaj would like. "The number of people washing cars has come down after the exercise. And the residents have seen for themselves that we haven't had flooding since we dug the wells. It is still the beginning; it requires leadership, which is not forthcoming," he says.
He maintains that rainwater harvesting cannot be as an individual thing — it doesn't matter if my well recharges my groundwater or yours. "At the end of the day, do you ask whose groundwater are you using when you dig a bore well?"