Citernes

A cistern, or citernes in French, is a container used to store liquids, most commonly water. The term covers both above‑ground tanks and underground reservoirs and can be applied to potable water systems, non‑potable water, rainwater collection, or other liquids. Cisterns are characterized by their purpose, construction, and materials.

Designs range from above‑ground tanks to underground reservoirs, and from vertical cylinders to rectangular vessels. They are commonly lined or coated to suit the stored liquid: concrete, steel, fiberglass, or high‑density polyethylene. Important features include access hatches, inlet and outlet connections, overflow, venting, and, for potable use, internal linings and filtration.

Common applications include building water supply, rainwater harvesting systems, industrial process water, and fuel storage for diesel or other liquids. Sizing depends on demand, supply reliability, climate, and whether the system relies on rainfall or external feeds. Rainwater cisterns are often equipped with sediment control and first‑flush devices.

Maintenance and compliance are essential. Typical requirements include leak testing, structural inspection, corrosion protection, cleaning to remove sediment, and regular checks of lids, seals, and vents. Proper venting, containment, and sanitary practices reduce contamination risks and help meet local health, safety, and environmental standards.