Water storage systems hold collected [[Rainwater Catchment]], [[Well Systems]] water, or delivered water for later use. Storage provides a buffer against supply interruptions, whether from drought, power outages, or equipment failure. Storage options include above-ground tanks, underground cisterns, and flexible bladders. The storage volume required depends on the number of users, the intended uses, and the reliability of the water source.
Polyethylene tanks are the most common above-ground storage option. They are available in sizes from 100 to 10,000 liters, are UV-resistant, and are food-grade safe for potable water. The tank is placed on a level, compacted gravel or concrete base. A dark-colored tank prevents algae growth by blocking light. The tank includes an inlet screen, overflow pipe, and a drain valve at the bottom.
Fiberglass tanks are more expensive than polyethylene but are stronger and more UV-resistant. Galvanized steel tanks are durable but require a food-grade liner for potable water. Concrete tanks are the most permanent option but are heavy, expensive, and can develop cracks over time.
Underground cisterns are buried below the frost line, providing cooler water that is protected from freezing and algae growth. They are constructed from concrete, polyethylene, or fiberglass. The cistern is buried with 30 to 60 centimeters of soil cover. Access hatches provide entry for cleaning and maintenance. A vent pipe screened against mosquitoes allows air exchange. A submersible or external pump draws water from the cistern.
Pillow-style bladders are used for temporary or emergency water storage. They are made from reinforced PVC or polyurethane and are available in sizes from 500 to 50,000 liters. Bladders are set on a smooth, level surface free of sharp objects. They are not suitable for long-term potable storage but are excellent for irrigation or livestock watering.