Hi Edreep,

just would like to share some input in your question.

Having an existing water tank in the school is already a good start. The task would then be to maintain them properly so that the existing facilities can still be used in the long run. 

Before looking at adding more water tanks, which usually require a good amount of investment, I would suggest looking first within the school for opportunities to conserve water especially looking at Sanitation and Handwashing facilities.

I would like to share some publications available in the SuSanA library which showcases water saving facilities.
-  Handwashing Facilities - Overview and Decision Support Tool
-  Compendium of Sanitation Systems and Technologies (1st Edition)

You can dig further in the library to find some publications that may of help in your context.

Of course, looking at the hardware / facilities side is one, but also equally important to look at how the schools manage these facilities to improve water saving techniques such as making sure that water outlets are not left open when not in use or by attending immediately to repair a leaking water connection.

I urge you to also sign up as part of the WinS network where we organize webinars around the WASH in Schools Topic across the globe.

Hope this helps.

Fred
WinS Network Secretariat

Many established African schools have put up some water facilities especially water tanks; you find that they are not enough for the entire population.
How best can such schools be supported?