The monsoon is India’s biggest opportunity to recharge your borewell. Miss it, and you wait another year.
An average 1,500 square feet roof can harvest 80 thousand litres during the monsoon season. Most of it flows into drains because systems aren’t ready when the rains arrive. According to NITI Aayog’s Composite Water Management Index report, 21 Indian cities, including Bengaluru, Delhi, and Chennai, are at risk of running out of groundwater, making rainwater harvesting not just beneficial but essential for urban water security.
Whether you’re installing a new system or maintaining an existing one, this guide ensures you capture every drop.
For New Installations: Don’t Miss This Monsoon
If you’ve been thinking about rainwater harvesting, now is the time to act. Installing during the monsoon seems logical, but it’s actually the worst time. Plumbers get busy with emergency calls. Testing becomes difficult. You’ve already lost the first few valuable rains by the time installation completes.
The installation itself takes just 2-3 hours in dry weather. But the cost of waiting is substantial. Your average roof loses around 80,000 liters of harvestable water if the system isn’t in place. That’s water worth ₹12,000 to ₹20,000 going to waste. Your borewell stays stressed for another full year, and the next monsoon opportunity is 12 months away.
Start by choosing your NeeRain filter based on roof size. The NRU 150 works well for household applications and uncontrolled public habitats, while the NSS 240 is for industrial and institutional use. Book your plumber now before the pre-monsoon rush begins. Complete the installation and test everything with buckets of water to ensure proper flow. When the first rain arrives, your system will be ready to capture every drop.
Systems installed before the monsoon catch 100% of the available rainfall. Mid-monsoon installation means you’ve already lost precious weeks of harvest. The investment of ₹5,000 to ₹12,000 one-time enables you to capture 80,000liters annually. Explore NeeRain systems and install before the clouds arrive.
Understanding India’s Water Challenge
India receives an average annual rainfall of 1,170mm, which translates to 4,000 billion cubic meters of water. However, with groundwater extraction rates far exceeding natural recharge in most urban areas, individual rainwater harvesting efforts have become critical. The Central Ground Water Board’s 2024 assessment shows that while groundwater recharge has increased by 15 BCM compared to 2017, the overall stage of groundwater extraction stands at 60%, with several states exceeding 100% extraction rates.
Your rainwater harvesting system directly addresses this imbalance by returning water to the aquifer during monsoon months, contributing to the national effort to restore groundwater levels.

The Pre-Monsoon Checklist
For those with existing systems, proper preparation makes the difference between capturing 90% or 50% of available water. Start your preparation about four weeks before the monsoon typically arrives in your area.
Begin by inspecting your filter housing thoroughly. Look for any cracks or damage that might have developed during the off-season. Make sure the lid closes properly and creates a good seal. Check that the wall mounting remains secure after a year of weather exposure. If you have a NeeRain filter with a transparent lid, ensure it’s clear enough for visibility during operation.
Cleaning both filter stages is essential. Remove the first stage filter that catches large particles like leaves and twigs. Then remove the second-stage filter that handles fine filtration. Wash both thoroughly under running water. For stubborn deposits that won’t wash away easily, soak the filters in a mild soap solution for about 30 minutes. Rinse them completely to remove all soap residue, then let them dry before reinstalling. A helpful tip: take photos before removing anything so you remember the correct placement when putting it back together.
Next, walk the entire route from your roof to the borewell. Check every pipe and connection carefully. Look for joints that have loosened over time. Examine pipes for cracks or damage. Clear any blockages you find in downpipes. Tighten any fittings that have worked loose. Make sure pipes maintain a proper slope so water flows naturally without pooling anywhere.
Your roof and gutters need thorough cleaning. Remove all accumulated debris, including leaves, bird droppings, and dust that has settled over the dry months. Clear gutters completely so water can flow freely. Check downpipes for obstructions that might block water flow. Remember, the cleaner your roof is at the start of the monsoon, the cleaner the water you’ll harvest.
If you have a first flush system installed, check that the valve works properly. Clean out the chamber and verify it empties correctly. If you don’t have one yet, consider adding this ₹1,300 component.{Add built in flush link} It prevents the dirtiest water from the season’s first rain from entering your borewell.
Don’t wait for actual rain to discover problems. Pour several buckets of water from your roof and watch it flow through the entire system. Check for leaks at every connection point. Verify that water actually reaches your borewell or recharge pit. The time to fix issues is now in dry weather, not during heavy rain when problems become emergencies.
Legal Requirements and Standards
Rainwater harvesting isn’t just a good practice—it’s mandatory in many Indian cities. The Bureau of Indian Standards has established comprehensive guidelines for rainwater harvesting system design and installation under IS 15797:2008 for rooftop systems and IS 14961:2001 for hilly areas. Properly implemented systems can significantly reduce groundwater extraction and cut water bills substantially.
Cities like Chennai, Bengaluru, Delhi, and Pune have made rainwater harvesting mandatory for buildings above certain sizes. If you’re in these cities, ensuring your system is ready isn’t optional—it’s a regulatory requirement. More importantly, it’s an investment in your water security.
During the Monsoon: Maximise Your Harvest
The first rain of the season deserves special attention because it carries the most dust and debris accumulated over dry months. When the rain starts, let the first rain wash your roof naturally. This initial flush clears away accumulated dust and prepares your roof for clean water collection. After this first wash, your system will harvest clean water for the rest of the season. If you have a NeeRain filter with a transparent lid, you’ll actually see the filtration working.
During intense downpours, understand that your system is designed to handle heavy rainfall. Water should flow smoothly through the filter. You might see some overflow if rainfall intensity exceeds the filter’s processing capacity, but this is normal and not a problem. The overflow mechanism exists specifically to prevent damage. Clean water should be reaching your borewell continuously. Don’t try to adjust anything during heavy rain. Let the system work as designed. NeeRain filters are built for the intensity of Indian monsoons.
After two or three heavy rains, do a quick inspection. Open your filter and check whether debris has accumulated inside. If needed, clean it out, which typically takes about 10 minutes. Remove any leaves that might have collected in your gutters. If you spot small issues, address them before they become bigger problems.
You can track your harvest impact with simple math. Multiply your roof area by the rainfall amount and then by 0.8 to get litres harvested. After a 50mm rain, your 1,500 square feet roof has captured 5,600 litres. That’s equivalent to 1water tankers worth in just one day.
Government Initiatives Supporting Rainwater Harvesting
The government’s commitment to water conservation is evident through multiple initiatives. The Ministry of Jal Shakti’s “Catch the Rain” campaign launched in 2021, has become an annual nationwide effort covering all districts with five focused interventions, including rainwater harvesting, water body restoration, and awareness generation. The campaign emphasises “Catch the rain, where it falls, when it falls” as a core principle for water security.
Under the Master Plan for Artificial Recharge to Groundwater-2020, the Central Ground Water Board has proposed 1.42 crore rainwater harvesting and recharge structures across the country to harness 185 billion cubic meters of monsoon rainfall. Your individual system contributes to this national vision of water security.
Common Mistakes to Avoid
Many people skip pre-monsoon maintenance, thinking that since the system worked last year, they can check it during the monsoon. This usually results in a clogged filter, lost water, and potential overflow problems when you least want them.
Another common mistake is not cleaning the roof beforehand. People assume rain will wash everything away naturally. The reality is that months of accumulated debris will clog your filter almost immediately, reducing efficiency dramatically from day one.
Some wait to test their system until actual rain arrives. This means discovering problems when fixing them is difficult or impossible. Testing with buckets in dry weather reveals issues that you can still address easily.
Installing during the monsoon itself leads to rushed work, water already being lost, and difficult testing conditions. Small issues that could wait in dry season become urgent during rains. A small leak grows bigger. A partial blockage becomes complete.
Quick Troubleshooting
If water stops flowing through your filter, the solution is usually simple. Remove and clean both filter stages thoroughly. Check the inlet pipe for blockages caused by leaves or debris. This typically resolves the problem in about 10 minutes.
When your filter overflows, it usually means filters have become clogged with debris. Clean them immediately and check whether the outlet pipe has become blocked somewhere downstream.
If water isn’t reaching your borewell, trace the pipe from the filter all the way to the borewell. Examine all connection points carefully. Pour water directly into the pipe to test whether flow is happening. This helps identify exactly where the blockage or disconnection occurred.
Call for professional help if you discover structural damage to the filter, major leaks you can’t fix yourself, or issues with the borewell connection itself. Contact your installer or NeeRain support for assistance with these more serious problems.
Calculate Your Monsoon Harvest
Understanding your actual impact helps keep you motivated throughout the season. The calculation is straightforward: multiply your roof area in square feet by rainfall in millimeters, then multiply by 0.8 to get liters harvested.
Consider real examples to see the scale. One moderate rain of 50mm on your 1,500 square feet roof captures 5,600liters. That’s the equivalent of 1 water tanker’s worth in a single day. One heavy downpour of 100mm captures 11,200liters, which represents ₹10,000 to ₹12,000 worth of water in just one rain event.
Over an entire monsoon season with 800mm average rainfall, that same roof harvests 89,600 liters. Since the average family uses about 2,00,000 liters yearly, you’re harvesting around half of your annual consumption. Check weather apps for daily rainfall data in your area. Calculate your harvest after each rain. Share these impressive numbers with your neighbors to spread awareness.
Post-Monsoon Care
When the monsoon ends around October or November, complete one final maintenance round. Remove and clean both filter stages thoroughly one last time. Clear any silt that has accumulated in pipes over the season. Inspect everything for wear and tear. If you notice any damaged parts, replace them now so you’re ready for next year.
Document your season’s performance. Note the total rainfall your area received. Record how the system performed overall. Write down any issues that came up and how you resolved them. Keep these notes for next monsoon as they’ll help you prepare even better.
Set a calendar reminder for April to start next year’s pre-monsoon preparation. NeeRain filters are designed to stay installed year-round, so no winter storage is needed. The system will be ready to start the cycle again when monsoon season returns.
Why This Monsoon Matters
Every liter you recharge helps more than just your own borewell. Your harvest contributes to your neighbor’s borewell since you share the same aquifer. It helps raise the local groundwater table. It reduces urban flooding by absorbing water that would otherwise run off. It decreases pressure on municipal water supply systems.
When rainwater harvesting becomes concentrated in neighborhoods, it changes the local water situation. Areas with high adoption rates see water tables stabilize and eventually begin rising. Your roof’s 80 thousand liters combines with harvests from neighboring roofs to recharge the entire area’s aquifer. You’re not just solving your individual water problem. You’re contributing to your community’s water security.
Don’t Wait Another Year
This monsoon brings 80 thousand to 1 lakh liters of water to your roof. Will you capture it, or let it flow away unused?
If you don’t have rainwater harvesting yet, calculate your roof’s potential today. Choose the appropriate NeeRain system for your roof size. Install by the end of April to capture this entire monsoon season. Every week you delay is thousands of liters lost.
If you already have a system installed, complete your pre-monsoon inspection by May. Test everything with buckets of water. Fix any issues you discover before the rains arrive. Be ready for 100% harvest when the first drops fall.
The monsoon is closer than it seems. April is for installation or preparation. May is for final checks and testing. June is when the monsoon arrives. Ready or not, the rains are coming. Make sure you’re ready to capture every drop.
Explore NeeRain rainwater harvesting systems to find the right solution for your home. Calculate your roof’s harvest potential to see exactly how much water you’re currently losing. Read what other homeowners are experiencing with their systems. Don’t let another year’s worth of free water go to waste. Start preparing today.
