BWSSB Rainwater Harvesting Rules Explained: Plot Sizes, Surcharge and Buyer Checks
A water bill with an unexplained extra line is how many Bangalore owners learn about rainwater harvesting. The line is a surcharge for a missing system, and it grows with time. This guide takes the rule by its numbers: the plots it covers, the water a system handles, how the surcharge works, and how a buyer can test a house, a plot or an apartment. Our team can help with general questions about Bangalore homes.
Three Numbers That Decide Coverage
It is the area of the plot that triggers the duty, not the area of the house. First comes a plot of 30 x 40 ft, about 111 sq m. New buildings on plots this size and larger have needed a harvesting structure since 2009.
The second is a plot of 60 x 40 ft, about 223 sq m. From here the Act reaches buildings that already exist, and the system has to hold rainwater, use it and feed groundwater. In the Act the figure is 2,325 sq ft or 216 sq m, and the amendment of 2021 drew older buildings fully under the rule.
The third is 1,000 sq m. On such plots, old and new buildings need dual piping, which lets stored water serve any purpose other than drinking, cooking and bathing. Almost every apartment project has a larger plot, so this band is theirs.
Who Makes the Rules
Section 72A of the 1964 BWSS Act contains the rule. It arrived with a 2009 amendment, and an October 2021 amendment, notified by the state, replaced the text. BWSSB drafts regulations and applies them through water connections. Within its service area owners and occupiers alike are bound, a tenant's bill shows the effect of a missing system, and a buyer takes the obligation over.
What a System Holds and Moves
The city's annual rain is between 900 and 1,000 mm. A roof covering about 111 sq m receives some 90,000 litres across a year, and that could cover a small household's non-drinking use for months. With no system, nearly all of it escapes into the drain.
The water takes a simple path. Gutters and downpipes receive it from the roof, a filter strains leaves and silt, and the clear water ends in a tank or sump, in a recharge well, or in both. Paved open ground is counted as catchment, just as the roof is.
BWSSB lays down a minimum capacity linked to the roof and paved areas, which storage, recharge or a combination may provide. A usual recharge well is a ring well, 3 m deep or more, about 0.9 m in diameter, dug on open ground within the plot.
The Surcharge and Beyond
A property without a system is charged an extra amount each month by BWSSB, set as a proportion of the combined water and sanitary charge. After three months the share rises, a non-domestic connection pays a higher share, and the charge continues until the Board is told that a system exists.
The same section holds a further power. Should an owner fail to build, the Board can put up the structure itself and collect the cost from the owner or occupier through the route for unpaid land revenue. Rates have been altered more than once, so the area's BWSSB office can give the present figure. At Jayanagar 5th Block, the Board's theme park displays designs for plots of varied sizes.
Budget and Upkeep
The cost for a house is made up of pipes, a filter, a sump or tank and a recharge well. Putting the system in with the house is cheaper, since sump and pipework share jobs with the plumbing. Fitting an older house afterwards costs more, mainly because of digging and changes to downpipes.
Upkeep takes only a few hours in a year. Before the monsoon, sweep the roof and gutters, and during the season rinse the filter now and then. Once a year, clear silt from the recharge well. Let the opening rains run to waste, since they wash down months of dry dust.
Testing a House or Plot
In a house, the system is one of the proofs of legal standing, alongside plan approval and khata. On a site visit, go through these points:
- Compare the plot size with the two house thresholds, about 111 sq m and about 223 sq m.
- Follow every downpipe to the filter, then to the sump or well.
- Go through three recent BWSSB bills for a harvesting surcharge.
- Look in the sump for dirt, and check the well for a sealed top or debris.
- Ask whether BWSSB was told, and whether the system is noted against the connection.
- On a plot, allow in the construction budget for a sump, a filter and a recharge well.
Adding a missing system is simple where the site has free space, and harder where the house fills the plot, so find out where a well could go. If a surcharge is outstanding, the seller should pay it before registration.
Testing an Apartment Project
In a flat, a single system serves the entire building, and the owners' association maintains it. Find out how the project deals with water from roofs, podium and driveways. The developer or the association should say how many recharge wells there are, how large the sump is, and what the dual pipes deliver to flush tanks and gardens, whether rainwater or treated water.
See whether the common-area bill has a surcharge, and find out who cleans filters and wells before each monsoon and what that costs every year. Tanker bills in summer fall when a system works, and so does the water that gathers in basements and driveways in heavy rain. Projects that depend on borewells gain the most, as the recharge wells help those borewells last.
