Vastu Shastra recommends some principles for construction of water sump in the building. According to Vastu, water elements should be available in the Northeast of the building. The following are some principles to build overhead and under ground water tanks.
Under Ground Water Tank/Water Sump
The best place for digging the sump is the North-east of the plot. This leads to increase in wealth, prosperity and knowledge. While digging the sump, an axis should be drawn from the Northeast corner to southwest corner. The sump should be dug to the right or left side of axis. The sump in east of northeast is most beneficial and the sump in north of northeast is also good.
Water sump should not be towards Southeast or Northwest. The sump in the Southwest is worst. Avoid water sump at the center of the house.
Overhead Water Tank
Overhead water tank should be in the West or Southwest direction of the building as these are negative zones of the house. Due to water in the tank, it becomes heavy, creates a balance of energies in the house and proves to be useful. Overhead tank in west direction is also beneficial.
Overhead tank should not be built in the Northeast of building. The tank in northeast direction will make it heavy; which is a big Vastu defect. It should not also be built in the South-east as it may cause loss of wealth and has adverse effect on health. Tank can be built in the Northwest of the house, but it should be small in size. Overhead water tank is not good at center of house as it is a heavy structure and will make the center heavy. Tank should be 2 feet above form the slab. There should not be leakage in overhead tank as it can cause outflow of money. Overhead tank should not be made of plastic. If it is of plastic, it should be of black or blue color as these colors absorb sun rays which create positive energy when absorbed in water.
Note: All above principles are applicable to residential as well as commercial buildings.