Underground water tank in Lahore

I've been living in Karachi for the past 2 years and something new and inspiring for me were the underground water tanks built in homes. Now that i am back to my own home in Lahore i was amazed by the scarcity of water developed here in Johar Town since the last 3 years or so.

Today at sehri there was no more water left in the tanks so I turned on my pumpjack there was still no water filling up in the tanks.. so without water doing sehri was a misery, however i managed somehow. I drove to the nearest WASA tank and tubewell supplier to my block and was told by the person there that their tubewell has been running up all night.

So when WASA turn on their tubewells and we turn on our donkey pumps there was still not even a drop in the taps or filling up in the tanks. Later when i got home my neighbours turned their pumpack off I got eventually the chance of filling up my tanks slowly.

This happens everyday that we rarely get a chance to fill up our tanks the whole day, In the coming years I see this problem getting worse. Drilling my own well and pumping water directly out is also not possible as we have tried this a decade ago and after a year or so there was no more water left under our home so we eventually got connected to the WASA grid.

Iv'e been thinking up on maybe building a underground water tank in our car porch as this will enable water flowing from the main water pipeline of our area directly into this tank, and there would be no need for a pump as this will be at the same level of that to the pipeline. Then using a conventional motor this water in the underground tank will be delivered to the tanks above.

However the question stands that here in punjab there is lots of rain all the time and lots of toads and frogs and other insects always there. Building an underwater tank maybe prone to these types of things attacking the water inside. I dont think anyone in our neighbourhood i know have made a below the surface tank, however some have basements in thier homes.. so i do not want to take any risks here in this investment.

I wanted to know if anyone of you already have a functional undergound water tank in lahore and problems related to it. Does the tank needs to be washed and chemicals added to it often? Is the water drinkable? will this be successful in saving up energy costs used to drive the Pumpjack (Donkey pump) ? And the big question that will the tank fill up efficiently than filling up the roof tanks directly using the pumpjack?

Every banglow have underground tanks, and the issues you are pointing out are something you should be handling in your own way.

Cleaning twice a year is a recommended practice, and using water filters for drinking water is most recommended.