Rainwater harvesting cost in Saran
That buys a filter on the downpipe and a recharge pit with a 60 ft recharge bore, which sends about 89,505 litres of Saran's rain back into the ground every year. The bore is the biggest cost, so the final price depends on how deep the water-bearing layer is under your plot; most groundwater monitoring wells in Saran read 5–10 m below ground.
Cost by building size in Saran
Each recharge pit (2 × 2 × 2.5 m with a 60 ft bore) takes the water from a 25 mm downpour on about 280 m² of roof. Bigger roofs need more pits.
| Building | Roof area | Recharge pits | Water put back a year | Cost |
|---|---|---|---|---|
| Independent house | 100 m² (1,076 sq ft) | 1 | 89,505 L | ₹87,000 to ₹1.4 lakh |
| Large house or villa | 250 m² (2,691 sq ft) | 1 | 2,23,763 L | ₹87,000 to ₹1.4 lakh |
| Small apartment block or office | 600 m² (6,458 sq ft) | 3 | 5,37,030 L | ₹2.4 lakh to ₹3.7 lakh |
| Housing society, school or factory | 2,000 m² (21,528 sq ft) | 8 | 17,90,100 L | ₹6.3 lakh to ₹9.6 lakh |
How the bore depth changes the price
The same house with a 100 m² roof, with the recharge bore drilled to different depths. The depth is set on site from the soil and water levels.
What is included
| Item | Rate before GST |
|---|---|
| Recharge pit 2 × 2 × 2.5 m: digging, brick lining, concrete base and cover with manhole | ₹28,000 to ₹38,000 each |
| Filter media in the pit: boulders, gravel and coarse sand | ₹8,000 to ₹12,000 each |
| 150 mm recharge bore with slotted PVC pipe | ₹300 to ₹500 a foot |
| Filter chamber on the roof downpipe (gravel, charcoal and sand) | ₹12,000 to ₹20,000 each |
| Downpipe connections, mesh guards, first-flush diverter and overflow | ₹8,000 to ₹15,000 per building |
GST at 18% is added on top. A storage tank for reusing the water, paved-area drains and silt traps cost extra. Prices are TerraSetu's estimates for 2026 and are confirmed after a site survey.
Is it worth it in Saran?
Saran pumps out 42% of the groundwater that can safely be taken out each year (2025, Central Ground Water Board), rated safe. Groundwater is within safe limits, and recharge keeps it that way as the city grows. A house system puts back about 9 water tankers of 10,000 litres a year.
Rainwater harvesting rules in Bihar
Bihar's building bye-laws require rainwater harvesting in buildings, and owners who install it get a 5% holding (property) tax exemption under the Bihar Municipal Property Tax Rules, 2013. An older rule under the 2006 Ground Water Act required RWH in building plans on plots of 1,000 sq m or more. A June 2026 draft of new building bye-laws proposes making RWH mandatory on all plots of 100 sq m or more, but it awaits Cabinet approval.
Get a quote in Saran
TerraSetu measures your roof, checks the soil and water level, and gives a fixed price for the system.
Frequently asked questions
What is the cost of rainwater harvesting in Saran?
A rooftop rainwater harvesting system with a recharge pit for a house with a 100 m² (1,076 sq ft) roof costs about ₹87,000 to ₹1.4 lakh in Saran, including GST, with a 60 ft recharge bore. The bore depth makes the biggest difference to the price; larger buildings need more pits.
How much water does rainwater harvesting save in Saran?
Saran gets about 1,053 mm of rain a year, so a 100 m² roof sends about 89,505 litres into the ground each year, roughly 9 tankers of 10,000 litres.
How many recharge pits does a building need?
One 2 × 2 × 2.5 m pit with a recharge bore takes the water from a 25 mm downpour on about 280 m² of roof. A house usually needs one pit; a 2,000 m² society roof needs about eight.
How long does it take to install rainwater harvesting?
A house system usually takes three to seven days: a day or two to drill the bore, two or three to build and fill the pit, and a day to connect the downpipes and filter.
Is rainwater harvesting mandatory in Saran?
Bihar's building bye-laws require rainwater harvesting in buildings, and owners who install it get a 5% holding (property) tax exemption under the Bihar Municipal Property Tax Rules, 2013. An older rule under the 2006 Ground Water Act required RWH in building plans on plots of 1,000 sq m or more. A June 2026 draft of new building bye-laws proposes making RWH mandatory on all plots of 100 sq m or more, but it awaits Cabinet approval.