Major Environmental and Sewage Management Reforms Introduced in Karnataka’s Municipalities Model Building Amendment Bye-Laws

On 21 February 2026, the Government of Karnataka notified the Karnataka Municipalities Model Building (Amendment) ByeLaws, 2026, introducing significant changes to the environmental and sewage management provisions.

Key Points of Municipalities Model Building Amendment Bye-Laws:

1. This Amendment revises the Karnataka Municipalities Model Building Bye-Laws, 2017, with the objective of modernizing urban infrastructure standards, promoting sustainable development, and strengthening environmental safeguards across municipal jurisdictions in the state.

2. It focuses on expanding the provisions of clause 15, which relates to environmental conditions and sewage management for large building projects.

3. Clause 15.12.A introduces sewage management provisions, applying to:

   • All new building constructions above 5000 sq.m built-up area

   • Extensions or repair of existing structures

4. It clarifies that these sewage-management requirements do not replace approvals required under other State or Central laws. In case of conflicting provisions, the more stringent rule will apply.

5. The new provisions mandate the installation of dual plumbing systems, consisting of:

   • Freshwater lines for drinking, cooking, and bathing

   • Treated water lines for flushing and other non-potable uses.

6. The bye laws strictly prohibit the discharge of untreated sewage or wastewater into stormwater drains, water bodies, or groundwater. Developers can utilize common off site treatment facilities only if treated water is reused and recycled as required.

7. In Building Category 1 (5000—<20,000 sq.m):

   Projects will provide onsite solid-waste management, install organic waste composting where need, and ensure 100% wastewater treatment via onsite STPs or septic-plus-greywater treatment. In sewered areas, developers can install STPs or discharge only black water with greywater treated onsite.

8. In Building Category 2 (20,000—50,000 sq.m):

   Requires onsite solid-waste systems, full STPs treating all wastewater for reuse, expert certification, compliance with CPCB/MoEF&CC norms, wastewater metering, CPHEEO-compliant sludge disposal, and recycling of treated water even when using common STPs.

9. In Building Category 3 (50,000—150,000 sq.m):

   Large projects will install onsite solid-waste and organic-waste systems, full-capacity STPs with mandatory reuse, certified adequacy, metering, CPCB-standard discharge, CPHEEO-compliant sludge disposal, and recycling of treated water even when using common STPs.

10. By expanding the scope of sewage treatment requirements, mandating dual plumbing systems, enforcing rigorous waste processing norms, and strengthening oversight of wastewater reuse, this amended bye-laws aims to:

    • Reduce the ecological footprint of growing urban centres.

    • Prevent pollution of groundwater and natural water bodies.

    • Encourage decentralized treatment and recycling of wastewater

    • Minimize the load on municipal infrastructure