Is Rainwater Harvesting Worth It for Businesses?
02/06/2025
Introduction – What Is Rainwater Harvesting?
You may be wondering what rainwater harvesting is and whether it is worth it for your business. It is the process of collecting rainwater from roofs and hardstanding areas for non-potable reuse within properties. Collecting from roof areas is considered best practice in the industry, as rainfall from this surface is the cleanest compared to surface water and therefore requires the least amount of filtration. This makes it the simplest and most cost-effective option for non-potable reuse.
Rainwater harvesting in commercial buildings can be installed either during the new build stage or via retrofitting. It works by collecting water from a building’s drainpipes into an above or below-ground storage tank, where it passes through a pre-tank filter before storage. The water is then pumped out via submersible pumps, either to a secondary header tank or directly to the point of use, depending on the system type. Systems with a secondary header tank pump from the header tank to points of use. At Stormsaver, we size our header tanks to provide the optimum capacity to meet the peak demand.
Applications
Rainwater is suitable only for non-potable uses, including:
- Flushing toilets
- Irrigation
- Vehicle washing
- Cooling systems and other industrial processes
- Washing machines
Benefits of Rainwater Harvesting
Installing rainwater harvesting in your business can have many benefits…
Financial Benefits
Rainwater harvesting reduces your mains water consumption, which in turn lowers your water bills. Traditional return-on-investment models assume the cost of water remains flat, this underestimates actual savings. In reality, water prices rise every year.
That’s why our expert team has developed a more accurate way to calculate your payback period - Progressive ROI.
How it works
Progressive ROI calculates the current cost of water in your area, estimates how much water your system will save, and applies the average annual water bill increase figure of 2.6% (based on Water UK data). It then projects cumulative savings over the next 25 years, providing a clearer picture of long-term value. You may even want to input your own data into our calculator, based on your past water price rises.
Get in touch with our team to find out more about how Progressive ROI works for your site.
Non-Financial Benefits
Rainwater harvesting offers numerous non-financial advantages, including:
- CSR & Reporting Compliance
Many large organisations must report on sustainability through frameworks such as the Task Force on Climate-related Financial Disclosures (TCFD). Incorporating water reuse supports the risk management aspect of these disclosures. - BREEAM Certification
Water reuse can contribute up to six BREEAM points if it meets 95% of the building’s non-potable demand, helping you achieve an Outstanding rating. This places your development within the top 10% of sustainable buildings in the UK. - Flood Resilience
Collecting and reusing stormwater helps reduce pressure on local drainage networks during heavy rainfall, minimising combined sewer overflows and reducing flood risk on-site. Local flood authorities and planning departments also view developments with water reuse more favourably due to the practice of sustainable water management, increasing your chances of planning approval. - Water Scarcity Resilience
Water utility providers are not legally obligated to supply water to non-domestic sites. In areas under serious water stress, new connections are being denied. Incorporating water reuse can be essential for securing approval for your connection. - Net Zero Alignment
Most people don’t realise that water reuse reduces carbon emissions. Reclaimed water undergoes far less carbon-intensive treatment compared to mains water, making rainwater harvesting a valuable strategy for reducing Scope 3 emissions.
FAQs
Can you retrofit a rainwater harvesting system?
Absolutely! Our expert team of estimators will assess your site, taking into account your roof area, applications, and average annual rainfall. A feasibility survey may be required before installation to determine the best system location. Our most popular retrofit solution is the StormStation, thanks to its convenient plug-and-play setup.
What system should I choose?
All of our rainwater harvesting solutions are bespoke. One of our estimators will design your system from scratch, ensuring it fits your site and requirements precisely.
Are there any other considerations?
Yes — rainwater harvesting systems require ongoing maintenance. At Stormsaver, we recommend biannual maintenance to ensure reliability and efficiency. Think of it like servicing your car!
Takeaways
Rainwater harvesting is a forward-thinking, sustainable solution that helps businesses save water and meet environmental targets. With a range of financial, environmental, and planning advantages, it's a smart investment for both new builds and retrofit projects.
Start your water-saving journey — contact our team today.
