Rainwater harvesting rules · sources up to 2026

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.

Note: The 2026 bye-laws were still a draft in the source. Check whether they have been notified.

Mandatoryfor new buildings

plots of 1,000 sq m and above (2006 Act); draft 2026 bye-laws propose 100 sq m and abovewhere the rule starts

Bihar Ground Water (Regulation and Control of Development and Management) Act, 2006; Bihar Building Bye-Laws, 2014the rule

Does it apply to your building?

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What the rule says

Applies to	residential, commercial, government
Rebates and subsidies	5% exemption in holding tax for buildings with RWH (Bihar Municipal Property Tax Rules, 2013)

Sources

Rules change and cities add their own. Check with your municipal body or development authority before you build.

Rainwater harvesting cost in Bihar

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Frequently asked questions

Is rainwater harvesting mandatory in Bihar?

Which buildings need rainwater harvesting in Bihar?

plots of 1,000 sq m and above (2006 Act); draft 2026 bye-laws propose 100 sq m and above: residential, commercial, government.

Is there a subsidy or rebate for rainwater harvesting in Bihar?

5% exemption in holding tax for buildings with RWH (Bihar Municipal Property Tax Rules, 2013)