Almost every Hyderabad house has an underground sump, an overhead tank and either a septic tank or a sewer connection, and many have a borewell. Their positions are both a Vastu decision and an engineering one — and both are best made before the foundation.
Commonly Followed Positions
| Element | Common Vastu position | Commonly avoided |
|---|---|---|
| Underground sump | North-east (north or east as alternatives) | South-west, centre |
| Borewell | North-east | South-west |
| Overhead tank | South-west | North-east |
| Septic tank | North-west | North-east, south-west, centre |
Construction Rules That Matter Just as Much
| Concern | Practice |
|---|---|
| Septic tank vs water sources | Keep the septic tank as far as possible from the sump and borewell, on the opposite side |
| Sump vs footings | Keep sump excavation clear of column footings; deeper excavation beside a footing can undermine it |
| Overhead tank load | A full tank weighs about 1 kg per litre — 2,000 litres is about 2 tonnes plus the tank; design columns and slab for it |
| Waterproofing | Sumps and tanks need waterproof concrete and plaster, and a pond test |
| Access | Covers for cleaning and inspection |
| Setbacks | Underground structures in setbacks must follow local rules |
Building the Sump
- Excavate to the designed depth, away from footings.
- PCC bed, then a reinforced concrete base and walls, or masonry with waterproof plaster where specified.
- Waterproof concrete with an admixture, and waterproof plaster inside.
- Cure thoroughly; then fill and test for leaks before backfilling around it.
Plan It All Before the Foundation
Sump and septic tank positions affect excavation, the drainage line and setbacks; the overhead tank position affects column and slab design. Give all four positions to your architect and engineer at the start.
The Short Version
Sump and borewell north-east, overhead tank south-west, septic tank north-west — and, just as important, septic tank far from water sources, sump clear of footings, and the structure designed for a full tank.
