When it comes to rainwater harvesting systems, one size doesn't fit all. The best system for you depends on factors like your local climate, the size of your property, and how you plan to use the collected water.
If visiting a store, don’t just ask for a tank. Let our experts understand the purpose so they can guide you into choosing the right tank and components. Watch out for the rainwater calculator that helps you estimate how much rainwater you can potentially collect based on your region’s rainfall patterns and property size.
For most homeowners, a simple rain barrel system is a great place to start. These are affordable, easy to install, and perfect for watering gardens or washing cars. If you're looking to go bigger, underground water tanks and cisterns can store larger volumes of water and can even be connected to your home's plumbing system for uses like toilet flushing and laundry.
Easy Steps to Set Up A Complete Rainwater Harvesting System
Complete Plastic Mart Rainwater Kit Contents for a Simple Rainwater Harvesting System
Although the number of accessories may defer depending on your unique application, here are the top 7 rainwater accessories we recommend for simple rainwater collection systems.
- Water level gauge for your water tank.
- A Flap Valve vent screen for the overflow piping
- A valve setup to fully utilize the water harvested
- A high water level overflow kit for higher collection capacity plus sufficient drainage space
- A leaf and debris filter
- First flush setup. We recommend one with different adapters to adapt with different pipe sizes.
Lastly, you’ll need your tank with an inlet screen to trap anything that shouldn’t enter the tank.
12 Guided Steps to Set Up Your Rainwater Harvesting System
Rainwater harvesting sounds exciting? We’re about to take it up a notch higher. It’s time to look at how to set up our rainwater collection system. Here are 12 steps to follow for setting up a simple dry/direct pipe rainwater harvesting system:
Start by ensuring the tank is standing on a firm foundation. This especially helps if you have erosion-prone soils or sandy soils.


1. Ensure Roof Surface is suitable for collecting quality rainwater. Get rid of extended branches as this will minimize the cleaning and maintenance costs.


2. Install Gutter Mesh to prevent debris and leaves from clogging downspouts. Ensure calculations are precise to avoid water blockage.

3. Next, fit the Gutter Outlets from the underside of the gutter to prevent obstruction of water flow
4. Fit your Leaf Eater or Leaf Beater rain heads to downspouts to further prevent blocking. Rain Heads deflect leaves and debris and keep mosquito out of the water pipes.
5. Install your First Flush Water Diverters (also called roof washers) to prevent the first flush of most contaminated rainwater from entering the tank. Fit to each downspout that supplies water to the water tank, cistern, or rain barrel, or install a large diverter that can handle multiple downspouts, beside the water tank or in-ground.
6. Install the Tank Screen to keep pests and mosquitoes from invading your tank.
7. Now setup the Rainwater Tank, Cistern, or Rain Barrel. While choosing the right rainwater tank size, consider annual rainfall, roof catchment area, and water usage.
8. Fit insect proof screens or Flap Valves to the end of all pipes to the tank screen and to tank/cistern overflow outlets to keep mosquitoes and pests out. Also ensures the rainwater tank is properly ventilated.
9. Utilize a Tank/Cistern ‘Top Up’ system if necessary to automatically top up from the mains water when the water levels fall to a designated minimum level.
10. Select a Pump System if need be to distribute water for use inside or outside the home.
11. Fit a purpose designed Rainwater Filter after the pump to help lower residual sediment, color and odour.
12. Finally, install a Water Level Monitor or indicator to assess water usage. Wireless systems are more convenient as you'll get the readings inside the home.
Rainwater System Installation and Maintenance: Keep Things Simple
Don't let the technical aspects scare you off – installing a basic rainwater collection system can be a fun weekend DIY project. However, for more complex systems, it's best to consult with a professional to ensure everything is set up correctly.
Maintenance is generally straightforward. Regular cleaning of gutters and filters, along with occasional tank inspections, will keep your system running smoothly for years to come.
Legal Considerations in Rainwater Collection: Know Before You Collect
Before you start collecting rainwater, it's important to check your local regulations. While rainwater harvesting is legal in most areas, some places have specific guidelines or restrictions. For example, in Colorado, rainwater collection was illegal until recently due to water rights issues. Now, residents can collect rainwater, but with certain limitations.
Most states encourage rainwater harvesting, with some even offering incentives. However, it's always best to do your homework and ensure you're in compliance with local laws.
Calculating Your Rainwater Harvesting Potential
Curious about how much water you could collect?
Here's a simple formula that gives you the average of rainwater collected per month:
Catchment area (sq ft) x Rainfall (inches) x 0.623 = Gallons of water
For example, if you have a 1,500 sq ft roof and your area receives 30 inches of rain annually, you could potentially collect about 28,035 gallons of water per month!
This rainwater collection calculator can ease these calculations.
Rainwater Harvesting: Not Just for Homes
While we've focused on residential systems, it's worth noting that rainwater harvesting isn't limited to homes. Commercial rainwater harvesting systems are becoming increasingly popular for businesses looking to reduce water costs and boost their sustainability credentials. From office buildings to agriculture and factories, the principles remain the same – just on a larger scale.
For instance, we’ve experienced a significant surge in car wash businesses looking to maximize on rainwater collection systems.
3 Common Mistakes When Installing Rainwater Harvesting Systems
- Don't place screens on top of gutter openings. This traps dirt and blocks water flow. Instead, install screens at downspout inlets to effectively filter debris while maintaining proper water flow into your system.
- It’s a good idea to get as much slope as you can so that water can run where needed as quickly as possible, but not too fast as well. A rule of thumb for gutter slope is a ¼“ drop for every 10 feet of horizontal run. This means that for every 10 feet your gutter runs, it should be a quarter-inch lower at the end than at the beginning.
- If you have more 90 degree angles in larger installations, consider using sweeping 90 degree angles for smooth water flow. A sharp 90 will cause water to stab and jolt.
Whatever the case, keep it super simple.
Top Considerations for Commercial and Industrial Rainwater Harvesting
Site Selection Tips
Choosing the right location for your rainwater harvesting system is crucial. Consider the following factors:
Roof Size and Material
Storage Capacity
Gutter and Downspout Configuration
Water Usage
Tank and Pipe Location
Ready To Start Your Rainwater Collection Journey?
As we've explored, rainwater harvesting is more than just a trend—it's a powerful solution for water conservation and sustainability. Whether you're a homeowner looking to reduce your water bill or a business aiming to boost your eco-credentials, implementing a rainwater collection system is a smart investment in our planet's future. By following the guidelines we've outlined and staying informed about local regulations, you can harness nature's bounty efficiently and responsibly.
Plastic Mart provides underground rainwater tanks for reduced visual impact, 54 gallon to 150 gallon rainwater barrels, and a diverse list of specialized rainwater tanks customizable to meet your unique needs.
Are you ready to make the most of that precious free resource? Contact Plastic Mart and let us be a part of your sustainability journey.