Chennai — CMWSSB connection compliance
Applying for a new CMWSSB water connection? You need an RWH compliance report first.
Chennai's mandate has been law since 2003. CMWSSB will not issue a new water or sewer connection without verified rainwater harvesting in place. Skip the rejection — generate your spec here, then pick from CMWSSB-area installers who've done it before.
Independent — we never install. Why →
Takes 60 seconds. The output is a one-page spec you take to a CMWSSB Resource Person inspection.
What CMWSSB requires
| Trigger | Rule |
|---|---|
| New CMWSSB water connection | Functional RWH structure must exist; connection denied otherwise. |
| New CMWSSB sewerage connection | Same rule. CMWSSB inspectors verify before connection is energised. |
| Building completion certificate | Withheld by local authority until RWH compliance is documented. |
| Existing buildings | Maintained RWH required — penalty + connection threats since 2014 enforcement push. |
Source: CMWSSB rules + regulations · CMWSSB rainwater harvesting page . Last verified 2026-05-12.
What happens if you skip it
- Connection application returned without action
- Sewerage application similarly returned
- Building completion / occupancy certificate withheld by Chennai Corporation
- Resale / mortgage paperwork delayed (most banks ask for the OC)
- Re-application requires fresh inspection + paperwork — 4–8 week delay
The four-step path to a working connection
- Generate your spec — our calculator returns roof area, system size, recharge pit count, and a compliance report PDF.
- Pick a CMWSSB-area installer — directory pre-filtered to Tamil Nadu installers with active CMWSSB inspection references.
- Install + photograph — installer commissions, you take catchment + tank + recharge photographs.
- Resource Person inspection + CMWSSB connection — inspection within 1–2 weeks, then connection issued.
Frequent questions
Is a self-generated PDF enough for CMWSSB?
Treat it as a planning document. CMWSSB's stated process requires inspection by a CMWSSB-approved Resource Person before connection issue. We generate the spec; the Resource Person verifies the install. The directory we hand you next includes installers who routinely work with CMWSSB inspectors.
How long does the inspection take?
Most CMWSSB Resource Persons can inspect within 7–14 days of install. Bring the RainbowHome-generated spec, installer's job-completion certificate, and a recent photograph of the catchment + storage + recharge.
What if my plot is too small for a separate recharge pit?
CMWSSB accepts storage-only systems for plots that genuinely cannot accommodate a recharge structure. Our calculator picks the appropriate system for your roof area and plot constraints. You can also recharge into an existing dug well or borewell with proper filtration.
Is this only for new buildings?
No. Tamil Nadu has required RWH for every building since 2003. New-connection time is when CMWSSB enforces it most strictly — that's why we built this funnel for that moment.
How does RainbowHome make money?
We get a one-time referral fee from the installer you pick. The compliance report and the comparison are free; we never take commission on conversion or mark up the installer's price.
Regulation reference: Tamil Nadu RWH mandate full guide. Last verified 2026-05-12. This self-generated spec is a planning document; CMWSSB acceptance requires inspection by a CMWSSB-approved Resource Person — see the CMWSSB website for the current list.