Thirsting for long-term solutions

Thirsting for long-term solutions

Thirsting for long-term solutions

A deadly double trouble stares Bengaluru City straight in the face this summer. Drying up fast, the Cauvery reservoirs might barely meet the city’s rising water demand. But an acute power crisis threatens to derail BWSSB’s contingency plans till June, pushing Bengalureans to the edge.

Pumping water from Cauvery in three stages over 110 km takes a whopping 120 MW of power, every day. Distributing this through 70 pumping stations within the City adds to that huge consumption. Load-shedding, scheduled and unscheduled, could play havoc with the system. Is Bengaluru ready, is BWSSB prepared?

The signs are ominous. Water levels have dipped 25 per cent in the four Cauvery river basin reservoirs of Harangi, Hemavathi, KRS and Kabini. BWSSB says reserving 1.5 tmcft of water every month till end of June might just help tide over the summer demand. But they aren’t so sure.

Power shortage could trigger a water crisis by May-end. Bengaluru’s voracious water demand in the summer heat could advance that crisis to even April.

Here’s why: Like every summer, borewells have dried up in thousands, groundwater table has dipped dangerously, rain-water harvesting and other water conservation efforts are still in their infancy.

BWSSB banks on the Irrigation Department’s assurance that priority will be for drinking water and not irrigation. But will this go well with farmers in the Cauvery river water basin? Lack of a long-term strategy to address the city’s recurring summer crisis makes this tricky balancing act inevitable.

No exclusive reservoir

The problem, as articulated by former BWSSB chief engineer M N Thippeswamy, is this: None of the four reservoirs upstream has water exclusively earmarked for water supply to Bengaluru.

Not a drop! Every year, demand from the city dictates the flow. This need-based system just does not suit a city of 10 million and rising.

Based on Bengaluru’s water demand over the next 25 years, the Australian International Development Agency (AusAID) had prepared a master plan that clearly indicated the need for an exclusive reservoir.

“Two locations were identified in the downstream of Shiva Anicut and upstream of Mekedaatu for a 2 tmcft balancing reservoir. But nothing materialised,” notes Thippe­swamy.

Depleted reservoir levels inevitably lower the velocity of water flow into the City. High evaporation losses further reduces the water volumes. Pilferage both in the river basin and inner city areas is another cause for concern.

Unaccounted water

Eventually, as the Water Board’s Chief Engineer (Maintenance) Kemparamaiah informs, only 600-700 MLD of the 1,370-1,380 MLD that is pumped from Cauvery is accounted for.
That’s a staggering 50 per cent lost due to factors that could have been controlled with better technology and management.

Bengaluru’s growth has largely been on its periphery, vast swathes of which comes under the erstwhile 110 villages brought under the BBMP limits. There is no BWSSB pipeline infrastructure here. The water tanker mafia reigns supreme here, their rates and water quality totally unregulated.

As a contingency measure, BWSSB too has proposed to engage all its 63 tankers and hire another 60 private tankers to cater to any shortage.

These would distribute water supplied by about 8,000 borewells owned by the Board. But many of these and a big proportion of the estimated 3 lakh private borewells could dry up as summer advances.

Depleting sources

Consider this: Barely 200 metres from Bellandur lake, a borewell dug in December could find no water even at 1,000 ft.

This story finds its echo in Marathahalli, Whitefield, Yelahanka, Sarjapur road and beyond. If groundwater table depletion is one issue, heavy chemical contamination of the precious liquid at such levels is another dangerous trend.  

Traditionally, the city’s water distribution network in residential areas has been designed for houses with one or two floors. But the city’s vertical growth, propelled by hundreds of multi-storeyed apartment blocks particularly in the 110 villages, has put a severe strain on the old network. A top BWSSB official admits that the Board can do nothing in areas that fall under the old villages. If the borewells dry up, lakhs of apartment residents here will have no place to go.

In the ultimate analysis, the crisis management clearly shows a gaping hole in planning, policy formulation and poor vision. The stress is always on contingency plans, much less on long-term solutions. As one Water Board insider says with biting sarcasm, even the water conservation awareness starts only by the end of January and lasts till June. This way, the last drop won’t last long. 

Based on City’s water demand over the next 25 years, an Australian International Development Agency master plan had indicated the need for an exclusive reservoir.

Two locations were identified in downstream of Shiva Anicut and upstream of Mekedaatu for a 2 TMCft balancing reservoir. But nothing materialised.

Only 700 MLD of 1,380 MLD pumped from Cauvery is accounted for. A staggering 50% is lost due to factors that could be controlled with better technology, management.

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