Water crisis in Bengaluru: Reviving lakes critical

“Water, water, everywhere, not drop to drink”, from The Rime of the Ancient Mariner seems apt for Bengaluru with most of its lakes and ponds polluted and frothing.

Despite covering about 70% of the earth’s surface, only 3% of freshwater is fit for human consumption. Water shortage in Bengaluru is a common phenomenon, especially during the summer months.

Many lakes in the city have been drained and the remaining ones are drying up. With over three lakh borewells pumping out groundwater, the water table is receding. The governments are doing precious little to revive the lakes. The only source of water for our city will be the pumped water from Cauvery.

Most of the ancient civilizations developed in different parts of the world in places where natural resources like water, fertile land and animals to hunt were available in abundance. Mohenjo-Daro and Harappa civilizations were located in the Indus valley.

Similarly, the region between rivers Tigris and Euphrates, the Mesopotamia region, witnessed settlement of many civilizations including the Persians, Greeks and Romans. Water is essential for the survival of humans, animals and plants. Thus, most of the civilizations evolved on riverfronts.

Even in modern times, most of the cities are located on riverbanks. Bengaluru is one of the few large cities in the world that is not on any major waterfront. Of course, there were many lakes in the city that provided enough water to the city population.

Water from the natural underground streams fed by rainwater was the input to these lakes. Thus, it was a self-sustaining system that worked for many centuries.

According to reports from the Indian Institute of Science, there were more than 265 water bodies in Bengaluru in 1972 when the city was spread over 161 sq km. But by 2016, there were 194 with the city extending to 741 sq km.

The trend of the city expanding and the number of lakes decreasing is because of the encroachment into the lake basin and concretisation of the catchment areas. Many lakes are intentionally dried up to create new residential colonies and for sand quarrying.

Bengaluru, with its population of 1.2 crores, requires 20-30 TMC of water for domestic use. Bengaluru urban district, on an average, receives about 870 mm of rain annually and amounts to about 22 TMC of water.

This water is not being saved because the city is mostly concretised and not much greenery or open land is left for the rainwater to seep into the ground to raise the underground water table.

Whatever water that collects in the remaining lakes is unusable because of the presence of pollutants.

The city is water-stressed and a majority of its water need is coming from the Cauvery river with Arkavathy river chipping in with a small fraction.

The reality is that 7,35,000 units of electricity are consumed to transport 4,700 crore litres of water into the city every month from KRS and Kabini reservoirs at a cost of Rs 46 crore.

This electricity can be used to develop some of the smaller towns and rural areas in the state to provide jobs to people. The exodus to Bengaluru will come down and the associated stress on infrastructure will automatically reduce.

All this is possible only if we can allow rainwater to seep into the ground and replenish the lakes and other water bodies.

The city and state planners, and administrators have to think of solutions to stop the random growth of the city simply because they also have to live in this city. A time may come when we have money, but we may have no water to buy.

Given the water situation, as citizens of the city, where can we save water? If one walks on the road during morning hours, in front of almost all the houses, there is a puddle of water from washing their front yard and vehicles.

In doing so, we are not only wasting water but also dirtying the roads. Vehicles going over the puddle of water will splash dirt back into our yard. The puddle of water on the roads also bothers pedestrians.

Senseless wastage

The bigger houses have bigger puddles of water because the entire driveway gets washed using hosepipes with water flowing continuously. Often, three or four cars belonging to big bungalows, are washed, including tyres, with hosepipes every day and then they are driven over the water puddles, dirtying the tyres.

These amount to senseless wastage of water. Wiping the vehicle with a dry cloth first followed by a wet cloth will give the same effect. The saved-up water from each house can be supplied to poorer localities and public toilets for encouraging “Swacch Bharat Abhiyan”.

The water distribution system is also very disproportionate in the city. The rich, powerful and influential localities have overhead tanks overflowing even during summers whereas less affluent localities suffer from water shortage.

Even if we are using borewell water, we should be conscious that we are depleting the groundwater and year by year, the water table in Bengaluru is going down.

According to a BBC report, Bengaluru is one of the 11 cities around the world that will run out of water. Pumping water uphill from Cauvery using large amounts of electricity (which is also in short supply) will be the only option for water supply for the city.

Borewells that are over 1,500 ft deep can only supplement water to some extent. It is not too late even now if the lawmakers along with BBMP can revive the lakes by clearing the catchment areas and polluting them.

The citizens also have to be responsible and sensitive to senseless wastage of water.

(The writer is with Energy and Environment Research Programme, School of Natural Sciences and Engineering, National Institute of Advanced Studies, Bengaluru)