The Bangalore Water Supply & Sewerage Board (BWSSB) has announced plans to make greywater recycling mandatory for all newly constructed buildings and detached houses in Bengaluru. The policy shift, once formalized, will expand the existing rule (which currently applies to large apartment complexes) to include individual homes.
Under the proposed framework, builders must install separate pipelines to segregate greywater (from bathrooms, wash basins, and laundry) from blackwater (toilet waste). Collected greywater would undergo treatment and be reused for non-potable purposes such as garden irrigation, toilet flushing, and cleaning.
BWSSB officials are preparing the policy details and intend to submit it for government approval by end-2025. The new regulation is designed as a phased rollout, beginning with new constructions, since retrofitting existing homes poses substantial technical and enforcement challenges.
Experts point out that such a mandate could significantly cut Bengaluru’s reliance on freshwater sources, especially the Cauvery river supply, and reduce pressure on sewer networks. Greywater reuse is expected to lower freshwater demand by as much as 40–50% in suitable buildings. Some real estate developers in Bengaluru have already started integrating greywater treatment systems in new projects as a forward-looking measure in response to deepening water scarcity.
Currently, BWSSB’s regulation for wastewater treatment and reuse is limited to apartment complexes having more than 120 units. The proposed expansion will extend its application to homes of all sizes, indicating a stricter environmental direction for the city’s building codes.
As Bengaluru continues to grapple with urban growth and escalating water stress, the move toward mandatory greywater recycling is expected to reshape building designs, increase compliance complexity, and raise expectations of sustainable infrastructure in residential projects.
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