Is Bangalore short of water?

Read in the newspaper this morning that "For 110 villages, Cauvery hope dries up", ref http://timesofindia.indiatimes.com/city/bangalore/For-110-villages-Cauvery-hope-dries-up/articleshow/24506031.cms. It seems the BBMP (the municipal council for Bangalore) had asked permission to take more water from the Cauvery river to supply potable water to the huge area it added to itself in 2007.

Let's do the math: Bangalore should be exporting water to the Cauvery basin, not importing it.

 975  mm rainfall/year (ref http://en.wikipedia.org/wiki/Bangalore)
 741  square km area (ref http://en.wikipedia.org/wiki/Bruhat_Bengaluru_Mahanagara_Palike)
 722,104,500  cubic meters water/year (calculated by multiplying rainfall by the ground area)
 10,000,000  population estimate (8.5 million ref http://en.wikipedia.org/wiki/Bangalore)
 72,210.45  liters water/year/person
 197.84  liters water/day/person

So we should be able to support nearly 200 liters of water consumption per person per day for each of the 10 million people in the 741 square kilometer catchment area of BBMP ... if we invested in water management as civilized cities are supposed to do.

Interestingly, the BWSSB claims to supply  900 million liters per day (ref http://bwssb.org/growth/, claiming 900 MLD = million liters per day). That is 90 liters of water/day/person for 10 million people, and 95% of this is from the Cauvery River. That's a lot of water ... a typical single-family home in the USA uses 262 liters/day (ref http://en.wikipedia.org/wiki/Water_consumption). With this level of supply already in place, we should also examine where all this water is going.

On droughts in India, and mismanagement of water

Strange to read articles about water shortage that do not mention how Jaisalmer or other dry parts of Rajasthan manage water. Jaisalmer gets 21 cm of water each year, and yet has no water scarcity (ref http://www.ted.com/talks/anupam_mishra_the_ancient_ingenuity_of_water_harvesting.html).

Let's compare Jaisalmer in Rajasthan to Jalna in Maharashtra, hit by a drought this year:
* Jaisalmer gets 20 cm rainfall/year (http://en.wikipedia.org/wiki/Jaisalmer)
* Jalna gets 78 cm rainfall/year (http://en.wikipedia.org/wiki/Jalna,_Maharashtra)

In 2012, Jalna received 32 cm, ref http://sandrp.wordpress.com/2013/03/30/how-is-2012-13-maharashtra-drought-worse-than-the-one-in-1972/, and is "hard hit" by drought, leading to shortage of drinking water and the threat of famine (http://in.reuters.com/article/2013/04/11/hunger-maharashtra-villages-drought-idINDEE93A0DC20130411).

Some are talking of mismanaged water, creating a man-made crisis in Maharashtra this year. The Aral Sea disaster (http://en.wikipedia.org/wiki/Aral_Sea) shows how ill-conceived irrigation schemes can cumulate to create an ecological and economic disaster area.

In Bangalore we talk of water shortages in spite of getting 97 cm of rain/year (http://en.wikipedia.org/wiki/Bangalore). We destroy the heritage of water management using lakes and watersheds and then fight about the water available to be taken from the Cauvery river, impoverishing its natural flow and causing uncalculated harm to the ecosystem.

Think: these water shortages are man-made, and can be solved with basic civic sense to manage water at a municipal level. How can Bangalore or Jalna learn from Jaisalmer?