RESTORATION OF LAKES AND WETLANDS

The ratio between salt and freshwater is always constant except under extreme climatic conditions. When the climate is very cold, much of the seawater is absorbed by glaciers and ice caps and freshwater increases at the expense of seawater. When the climate is very hot, glaciers and ice caps melt and sea water gains at the cost of freshwater. As a result of global warming, only the second process is taking place today.

Man is inflicting several pressures on lakes, watersheds and underground water sources, such as:

Freshwater diversion

Bioinvasion - aggression of exotic weeds

Depletion of groundwater

Watershed denudation

Pollution

Water mismanagement

Groundwater is a prime source of water. It is an invisible supply of water that seeps beneath the surface, collects in natural underground reservoirs known as aquifers and is a source of springs and wells. Groundwater is stable and reliable than any other resource, but is increasingly under threat due to greater demand caused by the increase in population. The effluents from industries are not disposed properly and it sets of a chain reaction and the toxic contents move through the water cycle and seep into the ground. Excessive withdrawal of groundwater, pollution or mismanagement can deprive future generations of this natural resource.

Groundwater is relatively free from pollutants and can be used for drinking, domestic use and industrial purposes. But once an aquifer gets contaminated, remedial measures can be cost intensive and even impossible. Because ground water is invisible, the dangers to it are often disregarded. High level of nitrate is seen in the groundwater in parts of India. This is because of the increased use of nitrogen fertilizer in the last decade (more than 300 kg/ha). The fertilizer consisting of urea, Ammonium Sulphate, Calcium Ammonium Nitrate and Ammonium Chloride form a layer on the surface. Flood irrigation and rain accentuate the entry into ground water. The other causes for pollution are unplanned urban development without adequate attention to sewage and waste disposal. It has several far-reaching consequences. The high nitrate level in the drinking water may get converted into nitrate in the gastrointestinal tract subsequently forming nitrosamines, which are carcinogenic.

Tailoring of technology in application of fertilizer, manure compost or city waste for crop products is needed. Abandoned dug wells invariably need to be filled. Research efforts should be galvanized to find a solution to the problem affecting millions.

The stench emanating from Varthur lake in Bangalore has made travelling to school or just breathing fresh air an ordeal for the students of K. K. English School a mile away.

Few students from the school had water samples from the lake tested for toxicity at St. Joseph's College, the results of which did not surprise them. Not only did the water show fecal contamination, it also contained bacteria, phosphate and algae. Results obtained from the Department of Environmental Science, St. Joseph's College, revealed that the dissolved oxygen content was not sufficient to even support the fish population. People bathe, wash their vehicles and even cattle in this lake.

They also visited doctors practicing in Varthur, to find that patients complained of gastroenteritis (caused by the E. coli present in the water), fever, vomiting, diarrhoea and bronchitis on a daily basis. That is because the leafy vegetables are first washed in this polluted lake before being sold in the market. Tests revealed that a bacteria Staphylococcus aureus, affecting the face and limbs, eye-infections, localised pain and fever is present in the lake water.

When the test results indicated pollution in the lake, the students and their biology lecturer approached the BWSSB, only to be told that they were working on beautifying other lakes and Varthur would get its turn too. They submitted a report to the State Government and are awaiting a reply.

The biology lecturer Mrs. Alli Rani and her team of students visited households in Varthur and asked them to take efforts to keep the lake clean. Taking inspiration from the above effort, schools and colleges should organise awareness rallies. The students should go on door to door campaigns, especially to the houses near the lakes and educate them about the importance of such lakes and their role in maintaining biological balance. They should give the people suggestions as to how they can help keep the lakes clean.

The Government should also play a crucial role in saving the lakes. It should enforce stringent laws for:

Prohibiting pollution by industries,

Heavy fining of those who use the lakes for dumping the effluents and washing their cattle,

The Government, especially the tourism department to convert the lakes into tourist attractions and the revenue thus generated to be used for the maintenance of the lakes,

The Government to ban the immersion of idols in the lakes,

The people to buy clay idols which are not painted and immerse them in buckets and use the clay in their gardens, and

The BWSSB to take up annual desilting and cleaning of the lakes by checking the growth of weeds.

I would like to thank the Times of India and The New Indian Express for their wonderful articles on this topic which have created awareness among the public. I also like to thank the Manorama Yearbook 2000 and the Britannia Encyclopaedia from which I have procured some information for this paper.