Water Tank / JoJo Sizing Calculator — South Africa

Water Storage for South African Households

Water security has become a significant concern for South African property owners. Municipal water supply interruptions — from infrastructure failures, drought restrictions, and load shedding affecting pump stations — can leave households without water for days. A properly sized water storage tank provides essential resilience.

The Department of Water and Sanitation (DWS) urban standard is 150 litres per person per day for full domestic use including drinking, cooking, bathing, toilets, and laundry. For planning a backup tank, this figure combined with your desired days of autonomy gives you the minimum required storage volume.

Standard JoJo Tank Sizes in South Africa

JoJo Tanks is the dominant manufacturer in South Africa. Their tanks are made from LLDPE (food-grade plastic), UV-stabilised, and available nationwide. Standard sizes are:

• 500L: Garden irrigation, small backup — R800–R1,500
• 1,000L: 1–2 person short-term backup — R1,500–R2,500
• 2,500L: Most popular residential choice — R3,000–R5,500
• 5,000L: Family backup 5+ days or rainwater primary — R5,500–R9,000
• 10,000L: Large property / small farm — R9,000–R16,000
• 20,000L: Farm, smallholding, commercial — R18,000–R30,000+

Rainwater Harvesting in South Africa

Rainwater harvesting collects water from roof surfaces during rainfall for storage and later use. The collection formula is: Annual collection (L) = Rainfall (mm) × Roof area (m²) × Runoff coefficient. Typical runoff coefficients: IBR/metal roof: 0.85; clay/concrete tile: 0.80; thatch: 0.60.