How to install a Rainwater Harvesting System

Harnessing the power of rainwater has become a popular way to contribute to sustainability, conserve resources, and reduce water bills. Installing a rainwater harvesting system enables you to collect and store rainwater efficiently, which can then be reused for various purposes such as garden irrigation, flushing toilets, and more. This guide will walk you through the step-by-step process of installing a rainwater harvesting system, ensuring you make the most of this eco-friendly solution with minimal hassle.

Why Harvest Rainwater?

Rainwater harvesting is not only environmentally friendly but can also reduce your dependency on treated water supplies. By capturing rainwater from your roof, you’re effectively reducing runoff that can lead to soil erosion and pollution of local waterways. Let’s dive into the simple steps to set up your own system.

Step 1: Pre-Installation Planning for your Rainwater Harvesting System

1. Assess the Suitability of Your Property

• Check Roof Type and Condition: Ensure your roof is suitable for rainwater collection. Ideal materials include metal and tiles. Avoid roofs with toxic materials.
• Evaluate the Catchment Area: Measure the size of your roof to gauge how much rainwater you can collect, maximising the system’s efficiency.
• Space for the Tank: Plan where to install your storage tank, considering surface or underground options based on your property’s layout and local regulations.

2. Gather Necessary Tools and Materials

• Tools: Measuring tape, level, and plumb line; shovel or excavator; and safety gear like gloves and goggles.
• Materials: Gravel for the foundation, pipework for connections, and a suitable rainwater tank.

3. Legal and Safety Considerations

• Research Regulations: Familiarise yourself with local building codes and obtain necessary permits. In the UK, the Water Supply (Water Fittings) Regulations 1999 and BS EN 16941-1:2018 provide guidelines for rainwater harvesting systems.
• Prevent Cross-Contamination: Ensure complete separation between non-potable rainwater and drinking water supplies by implementing an air gap, as required by UK regulations.

Step 2: Excavating the Site

• Determine Excavation Depth and Location: Plan for an underground tank by factoring in local soil conditions and the frost line. Ensure ample space for a gravel base beneath the tank.
• Consider Groundwater and Slopes: Install away from high groundwater areas and stabilise structures on slopes to prevent shifting.

Step 3: Install the Storage Tank

• Level the Tank on Gravel Base: Carefully position the tank in the excavation site, ensuring it is level to function correctly.
• Secure the Tank Turret: Attach the turret tightly to prevent leakage and allow for surface access.

Step 4: Set Up System Components

• Filter Installation: Fit a filtration system to clean the water before it enters the tank, protecting the system from debris.
• Connect Downpipes and Overflow Systems: Run pipes from roof gutters to the tank inlet and set up overflow systems to handle excess water.

Step 5: Backfill the Installation

• Use compacted gravel to backfill around the tank, supporting the structure and maintaining balance with water in the tank.

Step 6: Complete Rainwater Harvesting System Setup

• Install Dome Shaft and Control Panel: Ensure the dome shaft is level with the ground for maintenance access and configure the control panel.
• Connect Usage Points: Route pipes to connect the tank to garden taps or other non-potable sources. Clearly label all rainwater pipes to avoid confusion.

Step 7: Test and Maintain the Rainwater Harvesting System

• Conduct System Tests: Verify the flow of water through the system, checking for leaks and proper pump operation.
• Regular Maintenance: Clean filters, inspect pumps, and check control panels regularly to maintain system efficiency.

Have questions or need help? Contact our experts for personalised guidance on optimising your rainwater harvesting system today.