Currently, I have water from Or Bor Tor (City water) which goes through a filter into a 2,000 litre tank from there to the pump and into the house.

But supply is virtually non existent now and I have had a well dug.

Now I need to connect it to the existing system and I would also like to have a supply of water when the electricity goes off.

My idea is to put a pump next to the well, pump the water to a new 1,000 litre tank that will be placed on the roof (which is above the existing tank, filter and pump).

From the new tank the water will join the existing system before the filter. So it will go through the filter, then the original tank and then the original pump and into the house.

To get a water supply when there is no electricity, I intend to add a "bypass run" starting after the filter and rejoining after the original pump. It would bypass the original tank and original pump.

It would rely on gravity to push the water from the new tank into the existing system.

My question is: will it work both with electricity and without?

I have attached a diagram of my plans.

Any constructive comments gratefully received.

It looks like it would work. I don't see a valve for the bypass when not in use. Valved off only at the filter.

+1 ^^^

Also remember that a full 1000 L tank weighs over a Ton (actually it weighs a Tonne). Please ensure your structure is capable of supporting this load, we don't want you getting a sudden and rather large shower.