Rainwater harvesting reduces municipal water consumption, lowers utility bills, and supports sustainable building certifications (LEED, BREEAM, Green Star). Modular sectional tanks offer a flexible, scalable storage solution — from 1,000-liter residential systems to 10,000-liter commercial installations and beyond.
How Much Storage Do You Need?
Tank sizing depends on catchment area, local rainfall patterns, and intended use. A simplified approach:
- Catchment volume = roof area (m²) × annual rainfall (mm) × collection efficiency (0.8–0.9)
- Storage target = 2–3 weeks of average demand for the intended use
Common modular tank sizes for rainwater projects:
- 1,000L — single-family homes, garden irrigation
- 3,000–5,000L — multi-unit residential, small commercial
- 10,000L — schools, hotels, landscape-heavy commercial sites
- 50–100 m³ — municipal parks, industrial campuses, agricultural
Choosing Tank Material
GRP / SMC Fiberglass
The most popular choice for rainwater storage. Food-grade resin prevents algae growth on interior surfaces. Lightweight panels simplify rooftop and underground installation. Natural insulation reduces temperature swings that promote bacterial growth.
Stainless Steel
Ideal for containerized systems, premium residential projects, and applications where harvested water may be treated for potable reuse. Advanced sealing technology ensures leak-free performance in compact footprints.
Installation Options
Above ground — simplest and lowest cost. Place on a level concrete pad with adequate load bearing. Underground — saves space and keeps water cooler; GRP tanks excel here due to corrosion immunity. Container / modular skid — pre-assembled stainless units for rapid deployment on construction sites and remote locations.
System Components
- First-flush diverter to discard initial roof runoff
- Inlet strainer and insect screens on overflow vents
- Sediment filter before pump suction
- Level sensor and automatic pump control
- Backflow prevention if connected to mains water
Maintenance Tips
Clean inlet strainers monthly during rainy season. Inspect overflow and vent screens quarterly. Drain and rinse tank interior annually to remove sediment. Check gasket joints every 6 months — modular tanks make panel-level maintenance straightforward without replacing the entire vessel.
Planning a Rainwater System?
Tell us your catchment area, intended use, and available space. We will recommend tank size, material, and configuration.
Get Rainwater Tank Quote