Charged Rainwater Collection

Author: Brian Ashworth November 25, 2013

Thanks to SaveH2O, of Supadiverta

This diagram indicates a charged rainwater collection system. These are sometimes called either a “wet” or a “pressure” system.

NB. This diagram has been simplified for clarity. A leaf diverter, and an adequate overflow, must also be fitted.

With this type of system a section of the pipework always remains full.

As the pipes are under pressure it is essential all the joints in above ground and underground pipework are fully watertight.

ADVANTAGES

Allows you to discharge water at a height above the ground level at the down pipe (But not at the top of the tank – see the post: Inlet Improvements)
Neater than above ground pipework
Additional down pipes can be connected without diverting pipes along walls.

It is more likely to block as the flow through the pipes can be fairly slow and the low points can collect silt. (It is also more difficult to unblock.)
Higher cost than above ground systems due to trench excavation, and additional inspection fittings.
Potential for mosquito breeding in water unless appropriate screes are installed.
Harvesting additional downpipes without adequate overflow capacity can result in the tank overtopping during heavy rain.