Many of the lakes in Bangalore have "disappeared" along with their water-spreads and irrigated and catchment areas as rapid, unbridled urbanisation has taken its toll on the country's IT capital, a study has said.

The research study published by a city-based think-tank, Institute for Social and Economic Change (ISEC), paints a grim scenario on the preservation of lakes, the condition of many more of which would worsen if the State Government does not get its acts together.

The research, funded generously by the Sir Ratan Tata Deferred Endowment Fund, found that the available data with the Irrigation Department and the Directorate of Economics and Statistics surprisingly neither show any decline in the number of lakes nor irrigation potential created, in sharp contrast to the actual situation, an ISEC release said on Thursday.

"Besides this, the data on several aspects is missing," says the monograph's author, Dr P Thippaiah. "Even the existing information on various aspects shows wide variations across sources. For instance, the information on water-spread area of 125 lakes varies across sources."

The survey found beds and drainages of several tanks and had been utilised for forming residential layouts, construction of roads, public offices and shopping complexes, without any concern for the consequences such as flooding during monsoon.

The research which tracked the present characteristics of lakes, encroachment issues, rejuvenation of lakes and tank maintenance measures, underlined the need for the government to take sufficient care to keep the lake/tank inlets and outlets, catchments, natural drainages, tank structure and the command areas in tact while planning new projects and residential layouts.

"If possible, the tanks/lakes and their irrigated area (which is more fertile) should be kept out of acquisition, and dry land around them may be used for residential purposes," Thippaiah suggested in the monograph, titled 'Vanishing Lakes: A Study of Bangalore City.'

The government should also initiate appropriate action against individuals and companies who encroach on the tanks in collusion with officials by fabricating documents of encroached lands.

The study said Lake Development Authority (LDA), supposed to coordinate with several civic agencies and maintain a good data base about the tanks,has failed to prevent encroachments, largely due to lack of manpower and inadequate finances.

The management of all lakes, currently under LDA, should be transferred to Bangalore Development Authority and Bruhat Bangalore Mahanagara Palike, as they have sufficient resources and manpower to implement restoration programmes, it said.

There were also cases wherein private lease holders were found to overuse the lakes for commercial purposes and also encroach for expanding their activities.

Thippaiah suggested creation of Tank Users Groups (TUGs) who can be trained by LDA in matters of maintenance, for rehabilitation of lakes.

"It is the right time to take back leased out lakes from different agencies and departments, and entrust the same to the local residents for maintenance on the lines of TUGs in the rural areas," he observed.

It was seen that the rapid growth of IT, IT-enabled services, corporate sector and other business establishments in the city has caused rapid urbanisation, affecting several tanks.

In several parts of the Garden City, irreparable damage has been done to lakes with private individuals dumping wastes and discharging sewage water into them.

"Public awareness should also be created about the lakes. Schools and colleges should be involved in the maintenance of lakes," Thippaiah stressed adding "Engineering colleges are aplenty in Bangalore and can be directed to develop and monitor a lake/tank each."

It was also noted that restoration of lakes had become essential to enrich groundwater recharge, to mitigate drinking water shortage, particularly when bore-wells in Bangalore are drying up due to the overexploitation and loss of water bodies.