The 12 Steps of Rain Harvesting™
Rainwater harvesting is more than just installing a rainwater tank and connecting a few downpipes—it’s about building a smart, efficient system that maximises water collection while keeping it clean and ready for use.
At Stratco, we’re backed by decades of experience in Australian-made rainwater harvesting solutions, delivering quality, durability, and efficiency.
The 12-step approach, developed by Rain Harvesting™, provides a structured method to design a high-performance rainwater system tailored to your home, garden, or property.
Step 1: Understanding Your Rainwater Needs
Let’s start with the basics—how much water do you need, and what do you plan to use it for? Thinking about your water needs early helps you design a system that delivers both the right quantity and quality of water. Not sure how much water you’ll need? A quick look at your past water bills can give you a solid estimate.
Step 2: Choosing the Right Storage Solution
Now that you know how much water you need, let’s talk about where to store it. Stratco offers a range of water tanks in different sizes, materials, and styles to suit your needs.
· Above-ground tanks: easy to install, highly accessible
· In-ground tanks: space-saving, discreet, and ideal for large volumes
· Polyethylene tanks: lightweight and cost-effective
· Steel tanks: highly durable and suitable for residential and commercial use
· Concrete tanks: long-lasting and built for high-capacity storage
Placement is key too—make sure your rainwater tank is positioned for easy maintenance and connectivity. If your water needs grow over time, you can link multiple tanks together to increase your capacity!
Step 3: Optimising Your Roof & Collection Area
Your roof plays a key role in collecting rainwater, so keeping it clean and free from contaminants is essential.
· Avoid old lead-based paint, rusted metal, or cracked tiles
· Keep gutters clear of leaves and debris
· Install Blue Mountain Gutter Mesh to reduce maintenance and improve flow
· A well-maintained roof ensures higher quality water and less system upkeep
Step 4: Keeping Leaves & Debris Out
Leaves and debris can clog your system and impact water quality. Rainheads are a simple yet effective way to stop leaves before they enter your pipes.
· Rain Harvesting™ Leaf Eater filters out leaves at the downpipe, reducing blockages.
· A Rain Harvesting™ Tank Screen keeps out insects and fine debris.
With these in place, your system stays cleaner and more efficient.
Step 5: Diverting the First Flush of Rainwater
First Flush Diversion: Protecting Your Rainwater Quality
In Step 4, larger debris was removed. Now, the focus shifts to eliminating fine sediment, dissolved solids, and pollutants from your roof.
After dry periods, dust, leaves, and pollutants accumulate on your roof. When it rains, these contaminants wash into your system—unless you use a first flush diverter. This essential component redirects the initial, most polluted runoff before clean rainwater enters your tank.
Understanding Pollutants
There are two main types:
· Dry deposition – Dust, dirt, leaves, animal droppings, and airborne particles from roads or industry.
· Wet deposition – Pollutants like smoke, acid rain, or jet fuel from rainwater itself.
During the first few millimetres of rainfall, most contaminants are washed off—similar to hosing a dirty car. First flush systems divert this initial runoff, ensuring cleaner water enters your tank.
How Much Water Should You Divert?
The volume depends on your pollution level and water quality needs:
· Low pollution areas (low-density housing, no overhanging trees) → Divert 0.25mm of rainfall (25L per 100m² roof).
· Medium pollution areas (near roads, industry, or flight paths) → Divert 0.5mm of rainfall (50L per 100m² roof).
· High pollution areas (near heavy industry, agriculture, or dense tree cover) → Divert 1mm of rainfall (100L per 100m² roof).
There are different first-flush solutions, from small chambers to automatic diversion systems. Whichever you choose, diverting the first flush is crucial for maintaining high-quality rainwater.
Step 6: Securing Your System Against Contamination
Keeping your system secure prevents unwanted contaminants from affecting your water quality.
· Mosquito-proof screens prevent insects from breeding inside tanks
· Tank covers block sunlight, reducing algae growth
· Air gaps protect against backflow contamination
With Straco’s Rain Harvesting™ range, you can safeguard your water supply year-round.
Step 7: Choosing a Pump or Gravity-Fed System
With your rainwater collection optimised, it’s time to decide how water will move through your system. Your water usage, system design, and property topography will determine whether you use a gravity-fed system, a pump, or both.
Gravity-Fed System
Ideal when there’s sufficient height between storage and usage points, gravity-fed systems work well for low-pressure needs like irrigation or pool top-ups. If you have enough elevation, this is an efficient, power-free option.
Pump System
Pumps provide consistent pressure regardless of your system’s layout. When selecting a pump, consider water demand, required flow rate, elevation changes, and tank type. Consulting a specialist ensures the right choice for optimal efficiency.
Combination System
A pump can transfer water to a header tank, creating a gravity-fed system with built-in pressure. This setup lets you pump water at convenient times, such as when power is cheaper, improving efficiency and reducing energy use.
Step 8: Managing Standing Water
Maintaining High-Quality Rainwater
Collecting water is only half the battle—maintaining its quality ensures it remains fit for use. This involves managing both the water inside your tank and any water sitting in pipework throughout your system. The three key goals are:
1. Prevent sediment resuspension
2. Reduce algae growth
3. Prevent anaerobic fermentation in pipework
Draining Charged Systems
Wet or charged systems hold standing water in pipes between rain events, increasing the risk of stagnation and bad odours due to anaerobic fermentation. To maintain water quality:
· Minimise organic matter in pipes using rain heads
· Drain charged lines periodically using a manual valve or automatic drainage system installed at the lowest point.
The frequency of draining depends on debris levels, water quality needs, and how much water you’re willing to discard—some systems require draining after every rain event, while others can go weeks or months.
By applying these practices, you’ll keep your rainwater supply clean, fresh, and ready for use.
Stagnant water can lead to bacteria buildup. To keep your stored water fresh:
· Use a floating off-take valve to draw the cleanest water from the top
· Flush pipes regularly to prevent stagnation
· Ensure proper aeration to maintain freshness
Step 9: Installing Final-Stage Filtration
Water quality matters. Depending on how you use it, filtration needs will vary:
1. Irrigation & Garden Use
For irrigation, stored rainwater is generally suitable without additional filtration. However, sediment filters (100 microns or smaller) can protect irrigation systems from clogging and reduce maintenance.
2. Internal Appliances & Toilets
For indoor use, such as washing machines and toilets, rainwater quality must be free from sediment, tannins, and odours to prevent staining. A dual-stage filtration system is recommended:
· Stage 1: Removes sediment and small particles.
· Stage 2: A carbon filter improves water clarity and removes odours.
3. Showering & Drinking
For potable water, filtration must ensure the highest quality. A triple-stage system is ideal.
Your rainwater’s end use determines the filtration setup required. The broader your needs, the more advanced your filtration system should be to maintain clean, reliable water.
Step 10: Optimising Your Overflow System
Tank overflow is often overlooked, but proper configuration is crucial to maintaining an efficient rainwater harvesting system. Since most tanks aren’t designed to be fully pressurised, excess water must escape safely—especially during heavy rainfall.
Key Considerations for an Effective Overflow:
· Match or exceed inlet size – ensures excess water flows out properly, preventing inlet spillage.
· Install a mosquito-proof screen – prevents pests from entering while allowing smooth water flow.
· Choose a large mesh screen – reduces maintenance frequency and minimises blockages.
· Ensure easy screen access – allows periodic cleaning to prevent biofilm buildup and debris accumulation.
A well-designed overflow system prevents wastage, improves system performance, and helps capture more clean water—making it a key part of your rain harvesting setup.
Step 11: Monitoring Your Water Levels & Usage
Monitoring your water usage is essential—whether you rely on municipal supply or a rainwater system. Understanding your consumption allows you to conserve water, plan ahead, and optimise your setup.
Why Track Your Usage?
· Municipal water users can check their water bills for consumption trends
· Rainwater users need a gauge to monitor tank levels and prevent shortages
Modern tracking tools range from basic gauges to smart systems that sync with mobile devices for real-time monitoring. By tracking your water levels, you can:
· Analyse trends over time
· Adjust usage habits
· Optimise system efficiency
Choosing the Right Gauge
· Smart Gauges – automatically track daily and seasonal trends, storing historical data for better decision-making.
· Stnadard Gauges – provide a simple, reliable way to check water levels manually.
No matter which gauge you choose, tracking your usage helps maximise your rain harvesting system’s effectiveness and ensures a reliable water supply.
Step 12: Maintaining Your System for Long-Term Performance
Even the best rain harvesting system requires ongoing maintenance. Once set up, monitor it closely after the first rainfall to ensure everything is functioning properly. Key checks include:
1. Inspect Mesh Screens for Leaves & Debris
· Rain Heads – brush off leaves; covered models require more frequent cleaning
· Tank Screens, Overflows & Air Gaps – backwash or brush as needed to prevent blockages
2. Clean First Flush & Valves
· Check first flush outlets for debris buildup, remove the internal strainer, and backwash them
· Monitor debris levels to determine future cleaning frequency
· Inspect and clear release valves to prevent obstructions
· For wet systems, clean automatic wet-dry valves or manually drain charged lines
3. Check & Replace Final Stage Filtration
· As the last point before water use, these filters need regular checks
· Replace every six months to maintain high water quality
Building a Maintenance Habit
Frequent checks in the first few months after installation help establish a maintenance routine. Over time, you can adjust based on your system’s needs. With the right products and regular upkeep, your system will run smoothly for years to come
Shop Stratco for Rainwater Harvesting Solutions
If you have any questions on how to create your rain harvesting systems, feel free to contact us for more information or visit us in-store where one of our friendly team members will be happy to assist.