Water Blindness – a modern urban diseaseMay 30, 2013
2013 has been a strange year. April and May is seeing a staggering case of ‘water blindness’ in Bangalore. The media is full of reports on how the Krishna Raja Sagara dam on the Cauvery ( about 14 km. from Mysore City ) has reached dead storage level. The new Chief Minister of the State of Karnataka, India had to be consulted and water released from an upstream dam at Gorur on the Hemavathi River to the KRS dam. Police protection had to be ensured so that no farmers ‘stole’ the water en-route from one dam to the other. Water is released from the KRS dam and it reaches the Shiva Anicut downstream, from here the water is diverted to the Netkal balancing reservoir and is then pumped a distance of 95 kilo-metres and to a height of 300 metres to be distributed to the thirsty population of Bangalore.
As this riverine drama was going on, it was raining on the city itself. In the months of April and May, the driest and hottest months all across India, it poured all of 163 mm on the city. If you did the math, on the city of 1250 sq. km. which is the Comprehensive Development Plan area, the total volume of rain that fell would be a staggering 1,87,500 million litres. At the demand from the city of 1200 million litres per day, this water if harvested would have provided for 156 days of requirement. Granted that not all of it can be harvested and some is required for nature but even 50 % efficiency in collection would mean 78 days of supply.
Measuring rain is the first step to understanding it
Bangalore has made rainwater harvesting mandatory (www.bwssb.org). All old sites with over 240 sq mt plot area and all new sites with 120 sq. mt. mt. of plot area must have a rainwater harvesting structure. The rules are also simple – create 20 litre storage or recharge structure for every square metre of roof area. For the paved area on the plot, create storage or recharge structure of 10 litres for every square metre. The recharge structure itself should be 1 metre in diameter and at-least 3 metres deep.
If the good citizens of Bangalore follow the law there should be no water shortage in the fair city.
Individual examples: Some fascinating examples stand out. Mr. Balasubramanian, in the layout called Vidyaranyapura,in the northern suburbs of Bangalore has an old open well. The well which is 5 feet in diameter and about 30 feet deep had gone dry . He has recharged it using a simple drum filter filled with sand. The rooftop rainwater comes in through the filter and into the well. Since 2008 his well has not gone dry and provides him water right through the year. The water too costs him Rs 2.30 /- a kilo-litre, the cheapest water in the city. The quality of water in the well is only improving with time and recharge.
Mr Balasubramanian recharges the old open well in his house from rooftop rainwater
The well provides him all the water he needs for the year
Such is also the case with Mr. Chandra Shekar of Jayanagar 3rd Block in the Southern part of the city of Bangalore. He too has rejuvenated a well which is 50 years old. The fact is that rainwater harvesting keeps these wells alive and in an emergency even when there is no power water can be drawn through buckets thus providing electricity independent water.
The 50 year old open well of Mr Chandra Sekhar , recharged with rooftop rainwater and now full
Dr B.R. Hegde on the other hand has built a separate rainwater sump tank of 5000 litres capacity. He stores the rooftop rainwater and uses it for non-potable purpose.
Dr Hegde stores rooftop rainwater in a 5000 litre sump tank with the steel cover.
Rainwater Harvesting Theme Park: The Bangalore Water Supply and Sewerage Board have set up a theme park on rainwater harvesting in Jayanagar 5th Block. Here citizens can see more than 50 different types of rainwater harvesting possibilities including recharge structures as well as landscape and storm-water design which is rain friendly. A free consultation is also available with Engineers for a basic rainwater harvesting design. The BWSSB will also put you in touch with trained plumbers to carry out the job.
Rainwater harvesting theme park in Jayanagar 40th Cross,5th Block Bangalore
All in all rainwater harvesting is slowly but surely establishing its foothold in Bangalore. Once it becomes a mass movement, water should no longer be a constraint for the growth of this city. It is time to look to the skies and act rather than to look to the dams and complain.