Breathing life into city lakes

Breathing life into city lakes
Aggressive measures are being taken to ensure that the city's dwindling lakes are protected
The Times of India


Over the last 30 years nearly 200 lakes have disappeared in the city. Today, there are only about 81 and of these only 34 are recognised as live lakes. And in some of these live lakes, there has been a spate of fish deaths.

Bangalore has always been regarded as a 'garden city'. Years ago it was home to as many as 262 lakes. Lakes are important to human habitation as they address certain hydrological factors, provide a biotic environment, and are useful temperature comforts. Today, lakes have become endangered in the city because of many factors including encroachment and dumping of waste from both domestic and industrial sectors. And according to officials, the contamination of water bodies with waste and sewage has contributed heavily to the fish deaths happening in various lakes around the city.

Today, the government has taken a keen interest in protecting and restoring the lakes in the city. Various government departments have successfully restored numerous lakes like Ulsoor, Lalbagh, Madivala etc, and more such plans are on the anvil.

Action plan
According to environmentalists, the release of effluents into lakes has adverse effects on the ecology and environment. The resulting effect is that the dissolved oxygen level goes down in the water, weeds like water hyacinth proliferate and there's breeding of mosquitoes. Ultimately, this leads to the death of fish and other aquatic life in the lake. However, steps are being taken to remedy the situation and today there are systems in place that are trying to ensure that this is not a recurring problem.

According to officials, when there's a decrease in the oxygen content in the water, chemical treatments, like the addition of potassium permanganate and geolite, are immediately performed to increase the oxygen level. These treatments are as per the recommendations of the University of Agricultural Sciences. The desired dissolved oxygen level in the water for fish to survive is four mg/l and this level falls due to organic pollution. Since there's a tendency for fish to die when there's a decrease in the dissolved oxygen levels in the water, a check is kept on the level with the state's Pollution Control Board conducting tests at regular intervals for oxygen levels.

Another step that is being taken is to divert and shift the underground drainage systems near the lakes. This will ensure that sewage and other effluents don't flow into the lake thereby leading to the death of aquatic life. In fact, for some lakes these sewage systems have already been completely diverted. Sewage treatment plants are also on the anvil. In case the proposal goes through, water treatment plants are likely to come up near lakes in order to restore affected water bodies and to prevent lakes from getting polluted.

Fish in lakes
A senior official in the Horticulture Department says the types of fish released into the Ulsoor Lake for instance, are common carp, silver carp, katla and mrigal. The type of fish released into lakes again depends on the water, etc, but officials have been aggressive in ensuring that the number of fish in the lakes doesn't dwindle. In Ulsoor Lake for example, about three months ago nearly one lakh fish were released. According to officials, people can lease fishery rights for lakes that are managed by the Department of Fisheries at Rs 100 per hectare per year, with preference being given to cooperative societies.

Lakes and the citizens…
There are many things that an individual and resident's society can do to protect lakes and the environment. Here are some
Avoid the use of excess fertilisers and pesticides in your garden. These will eventually wash into storm water drains and thus into lakes
Buy organic products wherever possible
Recycle as much waste as possible
In case you live near a lake and use the shore regularly for walking or jogging, don't throw waste and other items into the lake. Ensure that there are waste bins around the lake
Ensure that storm water drains and sewage systems are separate. Ensure that plastics and the likes don't get into the storm water drains. Keep storm water drains covered
If you find there's a problem of weeds etc. in any lake, contact the authorities concerned