The Platin Retention Cistern is a dual-purpose rainwater system that combines stormwater attenuation with rainwater harvesting in a single underground tank.
Designed to relieve pressure on sewers during heavy rainfall, it uses a floating drain choke to release excess water into the channel at a controlled, delayed rate of between 0.05 and 2.0 litres per second, depending on site requirements.
Water held below the short-term maximum level remains available for reuse through a pressure-sensitive submersible pump that starts when a tap opens and stops when it closes, while an emergency overflow protects against extreme weather events.
The low-profile Platin tank is made from 100% recycled plastic and can be installed with simple gravel backfill, reducing installation costs and making it suitable for most Irish ground conditions. Available in sizes from 3,000 to 7,500 litres.
By combining retention with rainwater harvesting, the system can cut mains water use by up to 50%, supplying water for garden irrigation, outdoor cleaning, toilet flushing and washing machines