Hi Neeraj,
From your description it sounds like the device you want has multiple components. And it might be possible to measure, graph and communicate water usage with a number of device designs. You might want to narrow the possibilities by further defining the device. For example, is the device fully automatic? Is the water meter connected to the main household water supply?
You could conduct some background research on water meters used to measure residential water consumption. Also you might gather some information about how data from water meters might be transmitted to a smartphone (or computer) and graphed.
The Science Buddies project guide section on background research may be helpful to you as it includes information about how to outline and start your research:
https://www.sciencebuddies.org/science- ... earch-plan
Also, there is a Science Buddies project on water consumption. It describes a manual method for testing water usage that you might modify for your project. And some background information is provided that may be useful:
https://www.sciencebuddies.org/science- ... er#summary
I hope this helps. Please ask again if you have more questions.
A. Norman