As we know our population is increasing one comes in which it will replace the china in population this is also the reason that our most valuable natural resource that is water is going to decrease water reservoir has its own issue. In the Ancient method, water is enough for people because the population is in control but now days are changed. We are trying to save water on our campus so that we can use that water easily we can full fill the daily requirement of water. We need better technique than this but till then this is a cost-effective technique and we need to think for alternative cost-effective technique but anyway Rainwater harvesting is one of the best methods of fulfilling water requirements. In that project we are calculating the water from the rooftop and consider as the catchment area of our institutional building of JDCOEM campus we also design a tank for collecting the water The average rainfall in Nagpur is 896 mm in 2018 and that much quantity of water is going waste. With the help of rainwater harvesting, we can save water.