Water tank vastuVastu
Vastu for Water Tanks, Borewells and Septic Tanks: Placement on Your Plot
Where Vastu practice puts the sump, borewell, overhead tank and septic tank, what Indian public-health codes require between a well and a soak pit, and what to do when the two clash on a small plot.
Published on 10/16/202610 min read
About the guidance below: Vastu placements are described as practitioners and the classical texts state them. They are a tradition, and there is no scientific evidence that the direction of a tank changes a family's health or prosperity. The distances, by contrast, come from Indian public-health codes and protect your drinking water. Where the two conflict, follow the code, and check your city's own rules, which can be stricter.
Vastu practitioners commonly place an underground sump, well or borewell in the north-east, an overhead tank in the south-west, and a septic tank in the north-west. Indian public-health codes add a rule Vastu does not mention: a soak pit or dispersion trench should be at least 18 to 20 m from any drinking-water well, and 6 to 7 m from the house.
On most city plots you cannot meet both. This guide sets out each placement, the practical rule beside it, and what to do when they clash. For the rest of the house, see our practical guide to Vastu for a new home.
The common Vastu layout
Most practitioners give the same broad pattern:
- Underground water (sump, open well, borewell) in the north-east (Ishanya), with north or east as alternatives. Never an overhead tank or septic tank here.
- Overhead tank on the roof over the south-west (Nairutya), with west as the usual alternative. Most charts avoid the north-east, the south-east and the centre for it.
- Septic tank and soak pit in the north-west (Vayavya), with west as the usual alternative. Most charts avoid the north-east, the centre and above all the south-west corner.
Cement makers' home-building guides, such as UltraTech's pages on water tanks and septic tanks, repeat this pattern. Practitioners differ on the details: UltraTech's septic tank page, for example, allows the south side of the south-west zone in some conditions while forbidding the corner itself.
The classical texts are less uniform
The north-east rule for water is modern practice more than a single classical verse. In P.K. Acharya's 1934 translation of the Manasara:
- a well or tank goes in the north-east (Isa) plot of a temple complex (Chapter XXXII, verse 88);
- wells for a settlement go in the Antariksha, Agni and Pushan plots (XXXVI.27), which the same text places on the east side and at the south-east (VII.88 to 96);
- a royal palace's tank is dug in the north-west or the south-west (XL.100).
If someone says "the texts say north-east", it is fair to ask which text, and for which building.
Underground sump, well and borewell
Vastu: north-east, or north or east.
The practical rules:
- Size. The general guidance in the Model Building Bye-Laws 2016 asks for underground storage of 200 litres per person in new construction (clause 4.37).
- Distance from sewage. Keep the sump and borewell well away from the septic tank, soak pit and sewer line. The bye-laws' rainwater-harvesting chapter asks for recharge structures to be kept away from "sewer lines, septic tanks, soak pits" for the same reason (chapter 9).
- Permission. According to a Ministry of Jal Shakti comparison of the central groundwater guidelines, the 2020 guidelines exempt groundwater use by individual households, rural and urban, from needing a no-objection certificate. The same document notes that states can add stricter provisions, so ask your local body before you drill.
- Surface water. Our guidance: the sump's access cover should sit above the surrounding ground and seal well, so rainwater and floor-wash cannot run into stored drinking water.
Overhead tank
Vastu: on the roof over the south-west, or the west. Practitioners like it to be the highest point of the house.
The practical rules:
- Weight. A litre of water weighs about a kilogram, so a 2,000-litre tank holds about two tonnes of water. It needs to sit over beams or columns designed for that load, so tell your structural engineer where it goes before the slab is designed.
- Height limits. The bye-laws do not count roof tanks and their supports up to 1.0 m in height towards the building's height (clause 4.29.3), and they allow a screening parapet around tanks on the terrace (clause 4.12, note ii).
- Pressure. In practical terms, the higher the tank sits above the highest tap or shower, the better the flow.
Septic tank and soak pit
Vastu: north-west, or west. Avoid the north-east, the centre and the south-west corner.
First question: is there a sewer? If your street has a public sewer, connect to it and the soak-pit problem disappears. The CPHEEO manual describes on-site systems as "interim measures" until a decentralised or full sewerage system arrives (section 9.1).
Where a septic tank is needed, the Bureau of Indian Standards code IS 2470 (Part 1) says it should be open to the sky, as far as possible from the building's walls, not in swampy or flood-prone ground, and accessible for cleaning (clause 3.3.1). Plan for a desludging vehicle to reach it, which often argues for a spot near the gate.
Most of the risk comes from the soak pit or dispersion trench, where effluent soaks into the ground, rather than from the watertight tank. These are the distances the codes give:
| What | Minimum distance | Source |
|---|---|---|
| Soak pit or dispersion trench to any drinking-water source, such as a well | 18 m | IS 2470 (Part 2) cl. 5.3; Model Bye-Laws cl. 4.15.1 |
| The same | 20 m | CPHEEO Manual on Sewerage (2013), Part A, 9.3.4.4 |
| Soak pit or dispersion trench to the nearest building | 6 m (IS, bye-laws) or 7 m (CPHEEO) | As above |
| Leach pits of a twin-pit toilet to a tube well or dug well | 3 m in dry conditions with fine soil, 10 m where groundwater rises within 2 m of the pit bottom | CPHEEO, 9.3.3.3.1 |
Two more points from the same sources:
- Soil matters. CPHEEO recommends soak pits and trenches for porous soils, with a percolation rate below 25 minutes per cm and the water table at least 2 m down. It does not recommend them in limestone or fissured rock, where pollution can travel far. It also cites a National Institute of Technology Calicut study in laterite soil that worked out a safe well-to-pit distance of 21 m.
- Vent pipe. The bye-laws ask for a vent at least 50 mm across, about 2 m high if the tank is 15 m or more from the nearest building, and 2 m above the building's top if it is closer (clause 4.15.2f).
Where Vastu and the codes collide
Draw the usual layout to scale and the problem is plain. On a 30 x 40 ft plot (9.1 x 12.2 m), a borewell in the north-east corner and a soak pit in the north-west are about 7 m apart, and no point on the plot is more than about 14 m from the borewell. On a 40 x 60 ft plot, only a strip at the south end is 18 m away, and that is near the south-west, where Vastu practice least wants a septic tank.
The codes say "any source of drinking water", so your neighbour's borewell counts too. And the open space left after setbacks on a 30x40 or 30x50 plot is small.
Our guidance, in order of preference:
- Connect to the sewer wherever one exists. Then the septic question goes away. If you are still buying, add "is there a sewer?" to your plot checks.
- Do not rely on soil absorption where the distance cannot be met. Both IS 2470 (Part 2) and the CPHEEO manual point to treating effluent before disposal, for example in an upflow anaerobic filter or a biological filter, where a soak pit is not suitable. A local engineer can size one.
- Treat the borewell as non-drinking water unless it has been tested, if a soak pit, yours or a neighbour's, is closer than the code distance.
- Then fit Vastu around the safe layout. Most practitioners accept the west for a septic tank and the north or east for a sump, which gives more room to work with than the strict corners.
Living in a flat?
You cannot move the society's sump, tanks or septic system, and most practitioners focus on the flat's own layout. You can ask whether the building is on a public sewer, when the sump and tanks were last cleaned, and how far the sump is from any soak pit.
Frequently asked questions
Which direction is best for an underground water tank as per Vastu?
Practitioners commonly recommend the north-east, or north or east. Whatever the direction, keep it well away from the soak pit.
Where should the overhead water tank be as per Vastu?
On the roof over the south-west, or the west, and higher than the rest of the house. Make sure the structure below is designed for the weight: about one kilogram for every litre of water.
Which direction is best for a septic tank as per Vastu?
The north-west, or the west. Most charts avoid the north-east, the centre and the south-west corner. A sewer connection, where available, is better than any direction.
What is the minimum distance between a borewell and a septic tank?
The codes measure from the soak pit or dispersion trench: at least 18 m under IS 2470 (Part 2) and the Model Building Bye-Laws, and 20 m under the CPHEEO manual. Your city's rules may differ, so check them with your architect.
Do I need permission to drill a borewell at home?
Central guidelines exempt individual households from a no-objection certificate, but states and cities can be stricter. Ask your municipal body or state groundwater authority before drilling.
Planning a house with a borewell or septic tank? An architect can lay out the sump, tanks and soak pit to meet the code first and Vastu second. Find architects on MOA or interior designers on MOA who can plan your home with Vastu in mind.
Sources
- Central Public Health and Environmental Engineering Organisation (CPHEEO), MoHUA: Manual on Sewerage and Sewage Treatment Systems (2013), Part A, Chapter 9: On-Site Sanitation, sections 9.1, 9.3.3.3 and 9.3.4.4 (pp. 9-1, 9-14 to 9-16, 9-22), copy hosted by NIUA (accessed 16 Oct 2026)
- Bureau of Indian Standards: IS 2470 (Part 1):1985, Code of practice for installation of septic tanks: design criteria and construction, clause 3.3.1, via Public.Resource.Org (accessed 16 Oct 2026)
- Bureau of Indian Standards: IS 2470 (Part 2):1985, Secondary treatment and disposal of septic tank effluent, clause 5.3, via Public.Resource.Org (accessed 16 Oct 2026)
- Town and Country Planning Organisation, MoHUA: Model Building Bye-Laws 2016, clauses 4.12 and 4.15 (pp. 55 to 56), 4.29.3 (p. 66), 4.37 (p. 80) and chapter 9 (p. 112) (accessed 16 Oct 2026)
- Bureau of Indian Standards: National Building Code of India, to which the Model Bye-Laws refer for septic tanks (accessed 16 Oct 2026)
- Ministry of Jal Shakti: Comparison of existing (2015), notified (2018) and revised (2020) groundwater guidelines, slides on applicability and NOC exemptions, hosted by the National Green Tribunal (accessed 16 Oct 2026)
- Prasanna Kumar Acharya (tr.), Architecture of Manasara, Manasara Series Vol. IV (Oxford University Press, 1934), VII.88 to 96 (pp. 39 to 40), XXXII.88 (p. 299), XXXVI.27 (p. 399) and XL.100 (p. 428), via Internet Archive (accessed 16 Oct 2026)
- UltraTech Cement: Vastu for water tank and Septic tank Vastu, cited as examples of common practitioner advice (accessed 16 Oct 2026)