Rainwater harvesting cost in Changlang
That buys a filter on the downpipe and a recharge pit with a 120 ft recharge bore, which sends about 1,84,195 litres of Changlang'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.
Cost by building size in Changlang
Each recharge pit (2 × 2 × 2.5 m with a 120 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 | 1,84,195 L | ₹1.1 lakh to ₹1.7 lakh |
| Large house or villa | 250 m² (2,691 sq ft) | 1 | 4,60,488 L | ₹1.1 lakh to ₹1.7 lakh |
| Small apartment block or office | 600 m² (6,458 sq ft) | 3 | 11,05,170 L | ₹3.1 lakh to ₹4.8 lakh |
| Housing society, school or factory | 2,000 m² (21,528 sq ft) | 8 | 36,83,900 L | ₹8 lakh to ₹12 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 Changlang?
Changlang pumps out 0.5% of the groundwater that can safely be taken out each year (2023, 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 18 water tankers of 10,000 litres a year.
Rainwater harvesting rules in Arunachal Pradesh
Official replies say rooftop rainwater harvesting has been made mandatory through amended building bye-laws. The 2009 Arunachal Pradesh Building Byelaws (a final draft) require RWH provisions inside the plot on residential plots over 2,000 sq m and non-residential plots over 1 hectare. No smaller-plot rule was confirmed.
Get a quote in Changlang
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 Changlang?
A rooftop rainwater harvesting system with a recharge pit for a house with a 100 m² (1,076 sq ft) roof costs about ₹1.1 lakh to ₹1.7 lakh in Changlang, including GST, with a 120 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 Changlang?
Changlang gets about 2,167 mm of rain a year, so a 100 m² roof sends about 1,84,195 litres into the ground each year, roughly 18 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 Changlang?
Official replies say rooftop rainwater harvesting has been made mandatory through amended building bye-laws. The 2009 Arunachal Pradesh Building Byelaws (a final draft) require RWH provisions inside the plot on residential plots over 2,000 sq m and non-residential plots over 1 hectare. No smaller-plot rule was confirmed.