“A combined cistern typically refers to a type of plumbing fixture that combines two separate functionalities in one unit. It is commonly used in bathrooms for toilet flushing and also serves as a storage tank for collecting rainwater or harvested water. This design is often employed in sustainable water management systems to make the most efficient use of available water resources.
The combined cistern usually consists of two compartments or sections, each with its specific purpose:
Toilet Flushing Compartment: This compartment is responsible for storing and supplying water for flushing the toilet. It works similarly to a traditional toilet cistern, holding a certain volume of water, which is released upon flushing to clear waste from the toilet bowl.
Rainwater Harvesting Compartment: The second compartment is dedicated to collecting rainwater or harvested water from other sources, such as greywater from showers and sinks. This water is stored separately from the toilet flushing water.
How it works:
Water Collection: The rainwater harvesting compartment is designed with a collection system to channel rainwater from rooftops or other catchment areas. It may have gutters, downpipes, and filters to ensure the water collected is relatively clean and free from debris.
Water Storage: The collected rainwater is stored in the rainwater harvesting compartment until needed. This water is kept separate from the potable water supply to avoid cross-contamination.
Water Distribution: When the toilet is flushed, the flushing mechanism draws water from the toilet flushing compartment to clear the waste. The water level in this compartment drops accordingly.
Automatic Switching: There is a mechanism in place that automatically switches the water source for flushing from the toilet flushing compartment to the rainwater harvesting compartment once the water level in the flushing compartment falls below a certain threshold. This allows the system to prioritize using rainwater or harvested water for flushing, reducing the reliance on the main water supply.
Refilling: The rainwater harvesting compartment is continuously topped up with rainwater as it becomes available, ensuring a consistent supply for flushing.
By combining a toilet cistern with a rainwater harvesting system, the combined cistern helps conserve potable water and reduces the demand on municipal water supplies. This sustainable approach can lead to water savings and contribute to environmental conservation efforts. However, it’s essential to ensure proper maintenance and water treatment to avoid any potential health risks associated with using harvested water for toilet flushing.”