Water storage capacity

  • Water storage capacity is sufficient to meet user's demand for safe water at times of peak consumption throughout the day.
  • Total water storage capacity and safe water available during peak demand reflect differences in regional- and household water consumption.

Key indicators (India example)

  • Untreated and treated water container volumes: 9–12 L.
  • Total device capacity: 18–24 L.

Notes and exceptions

  • Peak demand volumes and total daily consumption will vary by region and market segment.
  • Clean water storage volume is large enough to provide “water on demand,” analogous to having a plumbed water tap in the house.
  • Storage and treatment rates are inversely related. If the treatment rate is higher, water can be made available more quickly, and the burden of storage is lower.

Example from India

  • 4 L per person per day (pp/d) is typical consumption for drinking and cooking in India.
  • Morning and evening meal preparation are periods of peak consumption in India.
  • Upper container volume reflects volume of typical regional water transport or storage vessels: 20 L is common for transport but difficult to pour; 12 L is a common storage vessel (“matka”) size and should be considered the upper limit for easy pouring.
  • Costs increase with increased device volume—a trade-off that must be explicitly made.

Supporting evidence

Girl standing and holding a large water storage container on her shoulder.

A family of five may consume 20 L of drinking water in a day, often making several trips to their water source. Photo: PATH.