Is It Possible to Connect a Cistern to a Rainwater System?

Designing the Connection

Connecting a cistern to a rainwater system requires careful consideration of the system’s design and layout. A typical connection involves installing a first flush device to divert the initial flow of roof runoff, which may contain debris and contaminants, away from the cistern. This device allows clean water to enter the cistern, ensuring the water quality is maintained. A typical first flush device consists of a diverter valve and a small tank that holds the initial flow of water.

Installing the Cistern and Piping

The cistern should be buried at a depth that allows for easy maintenance and access. A minimum depth of 3-4 feet is recommended to prevent freezing in colder climates. The cistern should be connected to the rainwater piping system via a suitable inlet valve. The piping should be sloped to allow water to flow freely into the cistern, with a minimum slope of 1:50 recommended. A check valve should be installed to prevent backflow from the cistern into the piping system.

Maintenance and Upgrades

Regular maintenance is crucial to ensure the cistern and rainwater system function efficiently. This includes inspecting the cistern for signs of damage or leaks, cleaning the first flush device, and checking the piping for blockages. Upgrades can be made to the system as needed, such as installing a larger cistern or upgrading to a more efficient first flush device. A well-designed and well-maintained cistern-rainwater system can provide a reliable source of water for irrigation and other non-potable uses.