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Soup bowls, good or bad?

Lake Ecology
Last Updated 15 February 2010, 10:50 IST
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In recent months, there have been angry and despairing comments about attempts to restore the dead and dying lakes of Bangalore. There is an outcry among birders who find that in several erstwhile wetlands where a variety of waders and waterfowl were seen in winter they now see massive earth moving equipment creating “soup bowls” in lake beds ostensibly for the storage of water. This  changes the ecology of the place making it unsuitable for many species of birds.

Apart from ducks, geese, cormorants, pelicans and fish eaters, several smaller species like sand pipers, plovers, blackwinged stilts, egrets and herons need squelch and only ankle deep water for hunting their aquatic insect prey. Deep waters keep them away, but human beings need water desperately, and storage in lakes from treated water from urbanised modern catchments, and rain of course, is the only handy source projected for the future. Groundwater has descended to unreachable limits by over use, and the Cauvery has been strained to its limits.

What then is the solution? We will come to it later, but here is not an irrelevant interjection. In July/August ‘07, when the Hebbal lake bed was dredged, birders and other groups were opposed to a private business house taking care of a natural public asset, and also bemoaning the fact that the physical change caused to the lake bed and its surroundings would result in several bird species disappearing.

Hebbal, a well-managed lake

According to the AT Ramaswamy Committee report on land encroachment, 2139 acres had been encroached on Forest Department land. Since the private house had the muscle and the finance to protect the area from land sharks around, it was decided that it would be best to leave management in their hands provided they agreed to the ecological imperatives which birders and conservationists suggested.

Today Hebbal is a well managed, well protected lake of great asset to Northern Bangalore. In fact it has offered free supply of water to the Horticulture Department for watering the plants on the airport road. The BBMP and others should now do the same with regard to their major plans of developing 143 lakes.

This is also the time when we must get the facts straight. Can the lakes of Bangalore be restored to their original ecological condition in the light of the enormous changes which have taken place to their catchments in the last three decades ? It seems to be impossible, but even if it is feasible, in view of our projected needs for water, “soup bowls” in our tank beds will have to be created for human needs in our major tanks. For the birds, a few of the smaller wetlands could be recreated on lines suggested by knowledgeable birders familiar with past conditions.

Soup bowls and their importance

Why are “soup bowls” necessary? V Balasubramanian, former Addl. Chief Secretary explains, “Bangalore is facing a ticking time bomb of drinking water famine by 2015. Its population in 2007 was estimated at 70 lakh in the BBMP area of 790 sq kms and the population has been growing at 4.9 pc annually.

At that rate, it will exceed one crore within five years from now. The final phase of Cauvery Water Supply Scheme of 500 million litres per day (MLD) will be completed by 2012 or 2013. With its completion, the total supply from all the Cauvery schemes will be 1310 MLD. The only other source is from Tippegondanahally whose availability has shrunk to 70 MLD thus making a total gross availability of 1380 MLD.”

There are no viable alternative schemes on the anvil to increase water supply. There is only talk of rainwater harvesting, digging more borewells, bringing water from Nethravati river, Almatti dam and diverting West-flowing rivers towards Bangalore, etc. Since the inlet channels and natural drainages have been blocked by widespread and blatant encroachments, rainwater does not flow into the cascading lake system of Bangalore devised by Major Sankey and instead, even with a 25 mm rainfall Bangalore, sitting atop a rock of 2900 feet, gets flooded. There are already 150,000 borewells in Bangalore whose water level keeps going down.

That leaves the only obvious, viable, common sense solution of making use of the lakes of Bangalore. It is not necessary to convert all the lakes into sources for drinking water. It is enough to select a few bigger lakes such as TG Hally, Bellandur, Hebbal, etc., and divert sewage drains from entering them and install Sewage Treatment Plants and use proven technologies such as clean-flow technology to clean up the selected drinking water lakes and supplement the Cauvery source.

There are over 900 lakes in Bangalore Urban district of 2,200 sq kms. Many of these can be restored for birds, marine life and use of citizens. Only a few lakes need restoring and cleaning to supply 1,000 MLD of drinking water.

Here then is the solution to one of our most serious problems. If the state government makes “soup bowls” in a few of the larger lakes, and restores the others keeping in mind the interest of birds and aquatic life generally, and as recreation areas, it will certainly improve our quality of life.

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(Published 15 February 2010, 10:50 IST)

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