Archive for May, 2013

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Monsoon preparations- Recharge wells – managing aquifer recharge

May 31, 2013

Many parts of the city of Bangalore have lateritic soil and highly weathered rock. By designing storm=water drains correctly and placing recharge wells such as this one, rainwater can be allowed to infiltrate and recharge the aquifer. This recharge well built in June 2004 will be completing 9 years shortly. On an average it has been sending in 1 million litres of rainwater into the ground each year. More such appropriately designed recharge wells will help improve groundwater levels , of course when balanced with managed and controlled withdrawal.

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A nutrient recycling system – looking at urban sanitation differently

May 30, 2013

City Ecosystem services and their management

A city needs a vast hinterland to support its population base as well as its economic engine. From here will come the food, water and other resources to keep it going. Of these water is a crucial limiting factor in the sense it has to be physically managed in large volumes to be delivered to every household daily.

Managing the catchment of the rivers which are the primary source for water will need to figure high on the list of priorities if a city wants to be sustainable and just.Catchment management will ensure that the forests and the groundwaters are protected so that the rivers continue to flow with high quality and quantity of water. These are upstream interventions for a river.

Catchment management can also mean taking care and protecting the water bodies within the city . Lakes and groundwater need to be kept away from pollution and encroachment as well as recharged with rainwaters.

Downstream needs : On the other hand the city also needs large areas of land downstream in a certain sense to manage the vast streams of waste that flow from it. Solid waste generated need land-fills as disposal areas. Liquid waste flowing through streams need large areas too for absorption of the nutrients.

In a strange conundrum the valley of the Vrishbhavati river is one of the greenest areas around Bangalore while the surrounding areas suffer from drought and a shortage of water. The city generates waste-water in the millions and about 500 million litres per day should flow out in the Vrishabhavati valley. The Byramangala reservoir , spread over 420 acres of land , receives all this water. It is a surprisingly scenic spot and deceptively beautiful .  Built in 1940 this reservoir continues to provide irrigation water through canals to many a farm field. The reservoir itself used to be a breeding ground for fish but all that has gone with the introduction of the African catfish into it.

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The deceptively beautiful Byramangala lake receives about 50 % of the citys waste-water

Downstream the waste-waters undergo a remarkable transformation. The soil , the vegetation and farmers transform this nutrient rich water into a green bounty. Slowly and surely as the river progresses one sees an improvement in the quality of the waters and by the time it joins the Arkavathy it can hardly be recognized as a foul smelling black stream which leaves the city. The Ecosystem services provided by nature is truly remarkable.

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Slowly but surely nature transforms black-water into better quality

This is not to say that there are no problems. Industrial effluents should not enter the stream at all . Domestic sewage too should be treated to a certain minimum standards before release to the river. Groundwater in around 50 % of the bore-wells was reported as contaminated especially with nitrates and bacteria according to a study. Farmers and field workers too have been reported to suffer from skin disease and other ailments.

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How green is my nutrient laden valley ?

While source control and elimination of the problem there is the best way it is still true that these waters are now essential for the livelihoods of hundreds.

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Can waste-water irrigation be integrated with the ecosystems approach of managing it?

Can the city think of identifying the entire area of the Byramangala reservoir and its command area as a zone which produces ecological benefits and for which the city should support the land and its cultivators ? Can this land be bought by the city and managed with the farmers and a palate of crops developed which will not enter the food chain of the residents of Bangalore? Can the villagers downstream be supported to access safe water and also be rid of the disease impact of using the waste-water? Can we think other than conventional waste-water treatment plants but say vast bio-diverse managed wetlands to clean the sewage that emanates from our city and for which each and every citizen is personally responsible? Can the institutions in our city rise up to the challenge and can the  city become ecological and water wise ? If any city can be the first this city has a fair shot at it.

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Water Blindness – a modern urban disease

May 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.

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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.

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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.

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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.

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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.

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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.

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Cities and water self-reliance

May 25, 2013

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Examining a recharge well – storm water will be infiltrated into the aquifer here
It is the last fortnight of May and the monsoon is eagerly awaited by the people dependent on dams for water. The Krishnarajasagara dam on the Cauvery had to get an infusion of water from the Hemavathi Dam upstream just to keep the water supply to the cities of Mysore and Bangalore going. Being on the banks of the Cauvery did not help Mysore much as it struggles to pump enough water in the pipes.

Ironically it is been pouring on the cities themselves. Bangalore has received more than 150 mm of rain as pre-monsoon showers. The rain accompanied with squalls on Wednesday evening was 40 mm as measured. What does this mean to the city?

Taken as a whole, the 1250 square kilometre of the city of Bangalore has received 187500 million litres of rain. At 1200 million litres per day this is the equivalent of 156 days of its water. These are staggering volumes especially because it has been raining on the city and not in the catchment of the dams. The rain gods are telling us to go and think local.

If every house had made provisions for rainwater harvesting and every tank in the city had been de-silted and linked to the catchment to collect the rainwater runoff, groundwater would have been full and there would be no shortage of water in the city.

Over a 100 square metre of roof area, 150 mm translates to 15,000 litres of water. On a 200 square metre roof area, typical of a 60 x 40 site construction 30,000 litres of rainwater has fallen in the peak months of summer when the rivers and dams are dry.

While the city as a whole may not be going on a war footing to catch the rain many citizens are. In the layout called Rainbow Drive on Sarjapur Road almost every alternate home is digging a recharge well. Typically these wells are 3 feet in diameter and about 25 feet deep. A recharge well can cost Rs 25,000 approximately.

Rainwater from rooftops is filtered and led into the wells. Storm-water flowing from roads and in drains can also be filtered and led into these recharge wells. This way no water is allowed to go waste and all of it goes to make up and recharge the groundwater keeping the bore-wells running.

A reader from Jayanagar 3rd Block, Mr. Chandrashekhar, is a long time resident of Bangalore. He has an old well in his home and has made provisions to direct the rooftop rainwater through a filter to his well.

The well has water for most parts of the year and he saves water for the BWSSB from anywhere between 6 to 8 months in a year. He makes the point that there are many such old open wells in Jayanagar and that all of them can become recharge structures.

People have built special sumps for rainwater and have not had to buy a single tanker of water in these crucial days of shortage.

It is time the good citizens of our cities realized the benefits of local self reliance and looking at the skies above rather than the dams afar for water. Harvesting rainwater in each and every building should be the mantra and the new government should take every step to make this possible as a mass movement.

Coimbatore and the wonderful initiative there called ‘Siruthuli’ is dredging silt from its big tank and making it ready to receive the monsoon. Similarly all tanks in the cities, be it Mysore, Bangalore, Hyderabad or Coimbatore, should be made ready to receive and store as well as recharge as much of the rains as possible.

Big dams alone will no longer be the answer to the growing thirst of our cities. Every effort from all citizens will need to be mobilized. In that lies water wisdom.

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Measuring the monsoon and harvesting the summer rain

May 24, 2013

harvesting the summer showers in a time of shortage

Summer rains are a great blessing to a city like Bangalore. While the dams on the rivers are running dry the city has received 163 mm of rain in the months of April and May. From a 100 sq mt roof area this is 16,300 litres of rainwater. Very, very useful if harvested and used.

Measuring the rain

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A letter from Mr E.A.S. Sarma to the Environment Minister , India

May 22, 2013
To
Smt. Jayanthi Natarajan
Minister of State (Environment & Forests)
Govt. of India
 
Dear Smt. Natarajan,
 
Subject:- Why re-examine the Gadgil Committee report on Western Ghats? How is the new Committee competent to undertake such a re-examination?
 
I refer to the comprehensive report submitted by the Committee constituted under the chairmanship of Prof Madhav Gadgil (HLWG report) and the report of yet another committee under the chairmanship of Dr. Kasturirangan to re-evaluate the HLWG report.
 
Having interacted with Prof Madhav Gadgil in one session while he was in the process of formulating his views on Western Ghats a couple of years ago, I thought that there could be no better person than him to evaluate the ecology of the Western Ghats and recommend measures to protect it. The Committee under his chairmanship had gone about in a systematic and professional manner and come up with suggestions that would save the Western Ghats and its resources for the posterity. I felt disturbed when MOEF had displayed inexplicable hesitation in releasing that report. It was under intense public pressure that your Ministry had to place the report in the public domain.
 
Western Ghats are rich in biodiversity and the health and the well being of their ecology will determine the future of that region for centuries to come. As a result of indiscriminately set up industrial and mining projects, the ecology of that region has already come under a serious threat.  The region cannot bear any additional stress. If at all, the stress that already exists may have to be reduced.
 
In fact, on the same lines as HLWG, I had earlier requested you to set up a similar expert committee to evaluate the threats to the Eastern Ghats. Perhaps, sensing opposition from your colleagues who are clearly in league with the crony capitalist promoters of industry, you have preferred not responding to my appeal.
 
Many of us felt distressed and distraught when your ministry had constituted yet another committee, this time under the chairmanship of Dr. Kasturirangan, Member of Planning Commission to re-evaluate the Gadgil Committee report. How is that committee more qualified to question Gadgil Committee’s studies? Did it not result in wasting the tax payer’s money?  Apparently, the Gadgil Committee report would hurt the interests of several corporates and, therefore, is unpalatable to the rulers of UPA! The way the HLWG report has so far been handled by the Prime Minister, the Planning Commission and MOEF confirms my strong feeling that most decisions of UPA are dictated these days by crony capitalists who seem to permeate the system like never before!
 
What worries me most in the latest report (Kasturirangan’s) is that it contemptuously dismisses the role of the people at the grass-roots in economic decision making. The authors of the latest report seem to be oblivious of the fact that the Indian Constitution begins with the words, “We, the people of India…” Ours is a democratic system. The authority that is implicit in the Constitution emanates from the people. The Gram Sabhas are a Constitutionally created entity. The real wisdom and the knowledge about the ecology of any region rest in the local communities. To think that the ultimate wisdom rests with the Planning Commission, or the South Block, or Paryavaran Bhavan, is to delude oneself.
 
I feel pained to read the letter written by Prof Madhav Gadgil to Dr. Kasturirangan on the latter’s report. I have enclosed a copy of that letter for your ready reference. I am sure that several persons among the civil society have also written to you, expressing their concerns.
 
I realise that MOEF has fixed a ‘deadline’ for submitting comments on the report and it so happens that today is that deadline! When the ecology of the country comes under the threat of crony capitalism of the worst kind, these deadlines have no relevance.
 
I fully endorse what Prof Madhav Gadgil has said in his letter to Dr. Kasturirangan. I wish Dr. Kasturirangan and his colleagues in his committee had the courage and conviction to tell MOEF that they would not re-evaluate Prof Gadgil’s report.
 
I request MOEF to reject Dr. Kasturirangan Committee report and, instead, accept HLWG report without any hesitation. The sooner that MOEF does this, the greater will be its credibility as a body obligated under Article 48A of the Constitution to protect the environment of this country.
 
I am confident that you will accede to this appeal unhesitatingly.
 
I have marked copy of this letter to the Prime Minister and Deputy Chairman of Planning Commission, hoping that they would introspect on what I have said here..
 
Regards,
Yours sincerely,
 
 
EAS Sarma
Former Secretary to GOI
Visakhapatnam
 
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Approach and solutions- Water crisis in Bangalore

May 17, 2013

As a blogger and a columnist in a newspaper it is still very pleasant to get e-mails like this below. 

Water Shortage – an Open well Rainwater Harvesting solution.

 
These are the days of water shortage. Krishnarajasagar (KRS dam on the Cauvery) is at an all time low in water level. Water rationing is round the corner.
 
Bangalore is well known for its open wells. So why don’t we revive and take care of our open wells?  Places like Malleswaram, Basavanagudi, Jayanagar and VV puram have large wells in the gardens of houses.
 
Of course, many old houses have been demolished giving way to apartment blocks. These depend on borewells and tanker supplies for their water needs. Occasionally BWSSB water is supplied.
 
I have a house in Jayanagar which is 50 years old. I have a well which is 35 feet deep and about 3 feet in diameter. Many years ago – around 15 years ago I installed rooftop Rain water harvesting structures. I collect around 1 lakh litres of rainwater each year of  three rainy seasons. I filter the collected water from the roof and feed it to the well. In about two weeks of rainfall, the well is full of filtered water. The attached photos will show the well Imagebrimming with water. These photos were taken last season.
 
I have estimated that I consume around 40,000 litres of water  each year from the well. The remaining 60,000 litres feed the ground water acquifers.  This is a substantial amount of water both for home consumption as well as ground water recharging. During the rainy season I am happy to shut off the BWSSB supply valve. When I use well water for all our needs, I not only save on my BWSSB bills but also precious Cauvery water which is now available for other users. 
 
The rain water harvesting solution is simple and one can do it oneself. It is a self help aid. The cost involved is only for the PVC pipes and filter. In my case I did the plumbing work myself.
 
I wish other citizens of our State help themselves and become self reliant as regards water needs. 
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Kindly publicise and popularise this concept so that we can overcome the present water crisis.
 
Thanking you,
 
S. Chandra Shekar.