We explain how to go from roof to storage, so you can plan a safe and reliable rainwater tank connection for your home. In the very first step we cover core plumbing priorities: screened inlets, first-flush diverters, ball valves, flexible couplings and overflow routing.
Our aim is to make the process clear. We focus on keeping debris out, protecting fittings, and ensuring a steady water supply to garden and household outlets. We also flag when to call a licensed plumber.
Practical tips: fit mosquito-proof strainers (≤1 mm), use a 200–500 mm inlet and a lower outlet with a ball valve and flexible coupling to absorb movement. Install a first-flush diverter to discard the initial runoff and fit covers to block sunlight and algae.
For urgent help with planning, installation or repairs in Melbourne, phone OnCall Emergency Plumbers on 1800 571 216. We’re available 24/7 for blocked drains, burst pipes and reliable, affordable plumbing work.
Key Takeaways
- Plan from roof catchment to outlet to keep water clean and system efficient.
- Use screened inlets, first-flush diverters and flexible couplings to protect fittings.
- Fit covers and pump enclosures to prevent algae and reduce noise.
- Check valves and overflows regularly to avoid leaks and compliance issues.
- Call OnCall Emergency Plumbers on 1800 571 216 for complex or urgent jobs.
Why harvest rainwater in Australia and when to call OnCall Emergency Plumbers
Collecting rooftop runoff can cut mains drinking water use by up to 40% and save roughly $200 a year. We see the biggest returns when captured water supplies gardens, toilet flushing and washing machines.
Proper installation matters. For systems tied to indoor fixtures, mains top-up or any electrical pump, hire a licensed tradesperson. We also recommend an electrician for safe power and auto-switching setups.
- Noisy or failing pump — call us urgently.
- Sudden loss of supply or blocked downpipes — get prompt help.
- Visible leaks or suspected cross-connections — contact us to protect your property.
| Typical use | Benefit | When to call a plumber | Outcome |
|---|---|---|---|
| Garden irrigation | Low running cost, quick payback | Blocked delivery or low pressure | Restored supply and efficiency |
| Toilet & washing supply | Reduces mains demand | Integration with internal plumbing or backflow needs | Compliant, safe system |
| Backup for outdoor taps | Resilience in dry periods | Noisy pump or suspected leaks | Reliable service and reduced lifecycle costs |
We provide 24/7 emergency plumbing across Melbourne. For fast help or scheduled installs, call OnCall Emergency Plumbers on 1800 571 216.
Plan before you plumb: regulations, location and sizing
Before any pipework starts, we map approvals, site constraints and sizing to avoid costly rework. Proper planning keeps your installation compliant and practical for long-term use.
Know the rules: council approvals, inspections and backflow prevention
Local councils may exempt systems up to 10,000 litres, but conditions apply. When you link supply to toilets or washing machines, a licensed plumber must arrange inspections and obtain a Certificate of Compliance.
We advise selecting the correct backflow device for any cross-connection and booking council or plumbing checks early.
Site and foundation: ground stability, mains avoidance and safe access
One thousand litres equals roughly one tonne. Design a base engineered for the load and avoid siting over water or wastewater mains.
Provide safe access for service work and keep pipes clear of trip hazards and obstructions.
Tank size, roof catchment and downpipe layout for optimal water supply
- Match roof area, local rainfall and daily use to pick the right size.
- Plan downpipe runs and pipe falls with minimal bends and serviceable inlets.
- Use compatible materials such as pvc with proper primer and confirm inlet and pipe diameters for the intended supply rate.
For regulatory advice, backflow selection and inspection-ready installs in Melbourne, we can coordinate compliant plumbing and emergency readiness. Call OnCall Emergency Plumbers on 1800 571 216.
Essential tank plumbing components and fittings that make the system work
Correct placement and quality parts keep systems reliable and easy to service.
The tank inlet should be a 200–500 mm top opening fitted with a ≤1 mm mosquito-proof screen and a snug cover to block light and reduce algae. Fit the outlet in the lower half with a ball valve and a ~300 mm flexible coupling to absorb movement.
Overflow belongs at the top and should discharge to stormwater or a secondary tank via screened elbows to stop pests.
Screens, diverters and valves
First-flush diverters capture the initial ~60 L of runoff and include a serviceable drain valve for cleaning. Floating intake screens on a hose draw water from below the surface and away from sediment at the bottom.
| Component | Purpose | Recommended material |
|---|---|---|
| Inlet screen | Keep insects and leaves out | Stainless mesh ≤1 mm |
| Outlet assembly | Controlled draw-off and isolation | Brass ball valve + flexible PVC hose |
| Overflow elbow | Safe discharge, pest exclusion | PVC with screened cap |
We favour brand-backed fittings, PVC with proper primers and compatible ABS adapters. For premium parts and professional installs, call OnCall Emergency Plumbers on 1800 571 216.
Step-by-step rainwater tank connection from gutters to tank
We take a practical, staged approach so the plumbing is durable and easy to service. Follow these steps to convert downpipes, run pipework to the inlet and finish the outlet and overflow correctly.
Downpipe conversion and diverters
Assess fall from gutters and choose appropriate pipe sizes. Convert downpipes using pvc drainpipe and fit a gate valve to control the first-flush diverter.
Use ABS sleeves where needed to adapt Schedule 40 fittings. Dry-fit and mark each joint before gluing. Once cemented, adjustments aren’t possible.
Pipe runs to the tank inlet
Lay out pipes with minimal bends and strap them firmly to walls. Use pvc or pvc/ABS compatible cement for sealed, leak-tight joints.
Connect to the screened entry at the tank inlet, checking height and clearance to avoid airlocks.
Overflow routing and outlet assembly
Route the overflow to stormwater or a secondary tank with screened fittings to stop pests. Tee to a second vessel if you want extra storage during heavy rain.
For the outlet, fit a reducer, short nipple and ball valve. Add a flexible coupling and unions to absorb movement and ease future service work.
Intake screens, backflow and mains top-up
Fit a floating intake screen with a lanyard so the pickup stays below the surface and above sediment as levels fall.
Where household continuity is required, install an auto-switching mains top-up and compliant backflow device. For licensed installs, backflow protection or emergency leaks, call OnCall Emergency Plumbers on 1800 571 216.
- Inspect every joint and valve for correct orientation and sealing.
- Ensure all fittings are serviceable and access is clear.
- Strap and support the pipe runs to prevent stress and future leaks.
Pumps, pressure and household use: from garden taps to washing and toilets
A well-specified pump and pressure tank make the difference between intermittent flow and smooth household supply.
Choosing pumps: external vs submersible, noise, efficiency and intake height
External pumps are robust and easier to service. Submersible pumps run quieter and save space.
Raise any submersible intake a short distance from the bottom to avoid sediment. Match pump size to the planned irrigation, toilet and washing duties to avoid oversizing and high bills.
Pressure management: pressure tanks, water pressure and consistent supply
Add a pressure tank to reduce short cycling and stabilise water pressure. This improves pump life and lowers energy use.
Install an auto-switch mains top-up for continuity with compliant backflow protection. For pump selection, electrical safety and pressure troubleshooting, we’re on call 24/7 in Melbourne on 1800 571 216.
Filtration considerations: drinking vs non-potable use and clogging risks
Decide filtration by intended use. Simple screens work for irrigation but filters for drinking need regular service.
Clogged filters can starve the pump. Fit a pump cover to cut noise and protect equipment, and check hoses, unions and seals regularly.
| Option | Pros | Cons |
|---|---|---|
| External pump | Durable, easy access for service | Noisier, needs weatherproof housing |
| Submersible pump | Quiet, space-saving | Requires intake lift from bottom to reduce sediment |
| Pressure tank | Stabilises pressure, reduces cycling | Requires additional space and periodic checks |
Testing, maintenance and troubleshooting for long-term performance
The final stage of any install is commissioning: pressurise, inspect and verify that pumps and safety devices operate as intended. We check every joint for leaks, confirm outlet operation and test electrical isolation for safe pump starts and stops.
Commissioning checks
We pressurise pipe runs and observe fittings under load. We verify pump cut-in and cut-out, confirm pump priming and measure water pressure at service points.
Routine maintenance
Keep gutter guards and downpipe screens clear of leaf build-up. Service first-flush drains and ensure overflows discharge correctly to stormwater or secondary storage.
Common issues and quick fixes
- Noisy or failing pumps — may be electrical or mechanical; test supply and replace worn seals.
- Low pressure — check for air ingress, blocked screens or hidden leaks in pipes.
- Ground movement — inspect straps and supports; resecure or replace stressed fittings.
For urgent plumbing repairs, burst pipes or ongoing leaks, we offer 24/7 response across Melbourne. Call us or book a roof plumber in Rockbank via roof plumber Rockbank for fast, reliable service using trusted components.
Conclusion
Finishing your system correctly ensures clean capture, durable fittings and trouble-free tank water for years. Fit screened inlets (≤1 mm), a first-flush diverter, secure outlets with ball valves and flexible couplings, and protect pumps with covers.
Choose the right water tank size for your roof and use, pick durable parts and unions, and route pipe runs to allow service access. Avoid siting the tank over mains and provide a stable base for safe, compliant installs.
We offer design, installation and rapid response across Melbourne. For dependable help with rainwater tanks, tank plumbing or urgent repairs call OnCall Emergency Plumbers on 1800 571 216.
FAQ
What plumbing considerations should we check when connecting gutters to a water storage unit?
We ensure the inlet is screened, sized correctly and positioned to avoid splashing and air entrainment. Downpipe falls, sealed joints and flexible couplings reduce stress and leaks. An overflow must discharge to a compliant stormwater point. We also allow access for inspection and maintenance.
Why harvest rainwater in Australia and when should we call OnCall Emergency Plumbers?
Collecting roof runoff lowers mains use, cuts bills and supports gardens during dry spells. Harvesting also reduces stormwater volume from your property. Call OnCall Emergency Plumbers on 1800 571 216 if you find leaks, pump failure, contaminated supply or suspected backflow — especially outside business hours.
What approvals and backflow prevention do we need before we plumb a system?
Council requirements vary. We check local regulations, obtain any approvals, and schedule inspections. A backflow prevention device is essential when the stored supply interfaces with mains so we prevent contamination and comply with plumbing codes.
How do we choose a site and foundation for a cistern to avoid damage?
We pick firm, level ground clear of mains services and with safe access for installation and maintenance. A concrete slab or compacted base prevents settlement and movement that can stress pipes and fittings.
How do we size the system for our roof catchment and household demand?
We calculate roof catchment area, average rainfall and intended uses to recommend storage size. Downpipe layout and fall determine collection efficiency. It’s important to balance supply with irrigation, toilet flushing and appliance needs.
What are the essential components and fittings for a functional installation?
Key items include a screened inlet, first-flush diverter, appropriately sized outlet, overflow with strainer, ball valves, unions and flexible couplings. Quality PVC and ABS parts, plus reliable pumps and covers, keep the system durable and serviceable.
Where should the inlet, outlet and overflow be positioned and sized?
The inlet sits near the top but away from turbulence; the outlet sits lower for gravity feed or pump suction. Oversize the overflow to handle heavy storms and route it to legal discharge. Strainers at inlet and overflow prevent debris and mosquitoes entering the supply.
How important are screens, leaf guards and sun protection for the system?
Very important. 1 mm mosquito-proof strainers and leaf guards stop pests and coarse debris. UV-protected covers reduce algal growth and slow material breakdown. Regular cleaning keeps performance high.
Do first-flush diverters matter and how do they work?
Yes. They divert the initial, most-contaminated runoff away from storage to protect water quality. The diverted water either drains away or returns slowly to the tank once the chamber refills.
Which valves and couplings prevent leaks and stress in pipe runs?
Ball valves and gate valves provide isolation for service and repair. Flexible couplings absorb movement and reduce mechanical stress on joints, lowering leak risk during ground shift or temperature change.
What materials and parts should we specify for longevity?
We use PVC pressure pipes, ABS adapters where required, stainless steel or brass fittings for valves, and quality pump brands. UV-rated accessories and solid unions make future servicing easier.
How do we convert downpipes to feed the tank and maintain correct fall?
We install diverters and adaptors at the downpipe, maintain correct fall to avoid ponding, and fit gate valves or isolation points for maintenance. Proper sealing and screening at every junction is essential.
What are best practices for pipe runs to the inlet?
Keep runs as short as possible, use correct pipe diameter to limit head loss, seal joints and screen the tank entry to prevent pests and debris. Slope the pipe gently and support it to avoid sagging.
How should overflow be connected to stormwater systems compliantly?
Overflow pipes must lead to an approved stormwater point or soakwell, include a strainer and be sized for peak events. Avoid discharging to neighbouring properties and follow local council rules.
What outlet plumbing is required for irrigation and garden taps?
Fit a ball valve, unions for easy pump removal, and flexible hose or piping to irrigation lines. Include isolation valves and an accessible sampling point so we can isolate and service the supply quickly.
How do we integrate mains top-up and protect against backflow?
Use an automatic switchover or top-up valve that includes backflow prevention. That prevents mains water entering the storage and keeps supply compliant with plumbing regulations.
How do we choose between external and submersible pumps?
We compare noise, efficiency, suction lift and ease of service. Submersible pumps sit in the water and are quiet; external pumps are easier to access but need priming and weather protection.
How do we manage pressure for household appliances?
We size pressure tanks and pressure switches to match pump output so supply remains steady. Pressure regulators protect appliances and ensure consistent flow to toilets, washing machines and taps.
What filtration is needed for drinking water versus non-potable use?
Drinking supply requires multi-stage filtration and disinfection; non-potable uses can rely on coarse and fine filters. We design systems to prevent clogging while meeting health requirements for potable use.
What commissioning checks should we perform after installation?
We conduct leak checks, pressure tests, verify electrical safety on pump installations, and confirm correct operation of valves, overflows and backflow devices before handing the system over.
What routine maintenance keeps systems working well?
Regularly clean gutters and leaf guards, service first-flush diverters, inspect strainers and overflow points, and test pumps and valves. A simple schedule prevents most failures and preserves water quality.
What common issues should we watch for and how do we troubleshoot?
Low pressure can mean pump faults, blocked filters or air in the line. Leaks often occur at joints or due to ground movement. We check seals, clear filters and test pumps; call us for complex faults or continuous leaks.
How quickly can OnCall Emergency Plumbers assist in an urgent situation?
We offer 24/7 emergency repairs and can be reached on 1800 571 216. Our team responds promptly to pump failures, major leaks, backflow risks and contamination events to protect property and supply.
