Using rainwater for different purposes in the house to save water consumption is known as a rainwater harvesting system. It is a technology to collect, store, and purify rainwater to remove pollutants and supply it with a proper plumbing system inside the house.
How to Use Rainwater For Toilet Flushing? You can use rainwater for flushing toilets by installing a rainwater harvesting system, which works by a gravity or centrifugal pump to draw water into the toilet tank. It provides many benefits, such as saving a lot of water, energy, and water bills, and an environment-friendly way to conserve natural resources. It is better to consider the tank size, space available to install it, tank material and price, and water consumption and pressure.
The process of rain harvesting reduces flooding and extra water collecting in the house or garden and utilizes it for better purposes. There is no need to filter it as you can use it for flushing without filtration or treatment if you have a low budget.
How can you use rainwater for flushing the toilet?
You can use the rainwater to flush the toilets through a gravity-fed harvesting system and use a centrifugal pump, which draws the water into the toilet tank.
The gravity-fed system does not need centrifugal pumps because the water moves down the cistern by gravity.
The harvesting system will need a centrifugal pump if the butt is placed at ground level and takes water to the cistern above ground level.
It is better to install two fill valves, such as the main water inlet and the rainwater valve. The main fill valve can fill the toilet tank when there is no more stored water inside the barrel.
Install all necessary plumbing connections from the rainwater tank or barrel to the toilet tank using PVC pipes from the barrel to the back wall of the bathroom. Connect the pipes to the tank and install a brass ball valve at the barrel base that controls the water pressure.
Attach the filter or screens and flush diverters to the downpipes, which prevents debris and other foreign particles from entering the tank water. It also diverts the water flow from the harvesting system to the toilets tanks.
Secure all the plumbing connections, and the rainwater barrel is ready to supply water to the bathroom or toilet. The water from the barrel runs towards the toilet tank and fills it with pressure when you push the lever or handle to flush the waste.
Why would you use rainwater for toilet flushing?
It takes approximately 11-12 liters of water per flush, and the average water use by each person is 30-35 liters per day which is a huge amount to consume in a day.
Water is a natural resource that is decreasing day by day because of excessive and improper use. Using rainwater for flushing the toilet can save a lot of water and conserve drinking water.
The water coming from the harvesting tanks is not drinkable, but you can use it to water the plants, flush toilets, and clean your garage or backyard.
It is an environment-friendly way to store and use natural resources and save them for future generations. Less water consumption causes a decrease in the bills and also saves the energy to draw more water into this place to fill the tanks.
There are chances of more water bills if you have a large family, as each person consumes many gallons of water daily. Therefore, people install the rainwater harvesting system to reduce their bills and save money.
It is easy to install the tanks to store and supply rainwater into the house through the pipes connected to the plumbing system. Use it as a backup source when the main supply line is interrupted due to plumbing repairs.
You can do the task of installing this system if you know the basic plumbing system and the connection of the pipe.
However, I called a professional plumber to install and connect the rainwater tanks and the harvesting system to the toilet tanks for automatic tank filling and flushing.
What are the disadvantages of using rainwater for toilet flushing?
Although there are many advantages of using rainwater for flushing toilets, some people avoid using it due to different reasons. For example, the water coming from the rainwater tank is naturally soft, but it may contain many pollutants from the gases in the atmosphere.
These pollutants and hard water can cause mineral deposits inside the tank and bowl. In addition, the components can get rusty if you use them without any filter or purifying unit.
The pH of rainwater is also high, such as it ranges between 5-5.5. This pH increases when it combines with other chemicals like nitrogen dioxide and sulfur dioxide in the atmosphere.
Unpredictable rain makes it difficult to rely only on the rainwater harvesting system for toilet flushing, as sometimes it does not rain for months.
Moreover, this system requires regular cleaning and maintenance, as it is prone to bacteria, mold, algae, rodents, and other insects. The initial costs for installing this system are high, such as it costs from $300-$2500.
It depends on the water volume you want to store and the number of people using the bathroom where the rainwater harvesting system is installed.
It can cause the water inlets to get locked if you do not install a high-quality filter to remove the pollutants, which also causes you to replace the plumbing fixture components.
Things to consider when installing rainwater tanks for toilet flushing
You should know these points when installing rainwater tanks to flush your toilet.
Size of tank and space available to install it
They have various sizes, and you can select the size depending on the space to place them.
Some people install underground systems to save space if they want to add a large barrel for more water storage. The size and shape of the barrel depending on the space available to install the system.
It is better to place it above the ground, as it becomes easy to clean and maintain the water barrels. In addition, it is easier and less exhausting to install the system above the ground as compared to the underground system.
Material of the tank
There are different types of rainwater tanks available in the market, such as fiberglass, polyethylene, and steel.
You can select a material that is durable, less prone to damage and mold accumulation. For example, polyethylene tanks are more durable and can resist intense UV rays.
People also install fiberglass tanks because they are more resistant to corrosion, rust, and extreme temperature changes. However, you can select concrete and steel tanks because they are also durable and budget-friendly.
Water consumption for flushing
It is better to consider the water consumption for flushing the toilet, as you need a larger tank to store more water if you have a large family.
More water consumption causes more bills; therefore, finding other ways to save money is better. For example, you can install a larger rainwater harvesting system if you have a busy household and often have overnight guests.
People install more than one tank to store and collect more water if the water consumption is high; however, it needs more space to accommodate more tanks.
Price of the tank
The price of the rainwater tank depends on the size of the tanks you want to place in your house. For example, a 2500-3000 L tank is sufficient for a family of 2-3 persons, and it can cost $2000-$3200, depending on the material and size of the tank.
It can cause more money if you hire a professional to install the system and select the filters and other components. However, installing this harvesting system is worth it because you can save approximately $200-$250 per year from your water bills.
Water pressure is another essential factor to consider because it can cause problems in flushing if the pressure is too low. As a result, it cannot flush the waste properly into the drain and causes clogging or another issue over time.
Rain often comes after months, and the pressure inside the tank becomes low; therefore, it is better to connect the main water inlet with the tank to get sufficient water pressure when there is no rain at all.