What Is A Commercial Rainwater Collection System?
The commercial rainwater collection system can also be called rainwater harvesting system. That is, rainwater is accumulated on-site for other purposes without losing rainwater. The commercial rainwater collection process can be completed according to five steps: collection, storage, filtration, storage, and utilization.
The Applicable Scope of a Commercial Rainwater Collection System
Commercial rainwater collection systems can installed in various places such as airports, stadiums, factories, communities, agricultural irrigation, etc.
The Main Process In a Commercial Recovery Collection System
- Collect rainwater
There are two ways to collect rainwater: one is pulling the tube from the eaves or the top floor ground. The other is collecting from the ground surface. There are different ways of collecting rainwater according to different methods. - Store Rainwater
Rainwater will pass through pipelines into any form that can store; for example, water tanks. - Filtration
This process is to remove impurities, and sediment, and even disinfects, which turns the rainwater into clean water that is ready to use. - Store Cleaned Water
The filtered and purified water is stored respectively in other water pools. - Application
The purified water can either support groundwater or be used for various purposes: plant irrigation, toilet flushing, floor washing, etc.
The Application of Rainwater
- Gather into public groundwater
- Greening environment: planting irrigation, ecological pool
- Domestic use: toilet flushing or floor mopping
- Reduce the impacts of emergencies or natural disasters: water restrictions, droughts, fires, etc.
- Non-drinkable water sources - other industrial uses or agricultural irrigation.
The Benefits of Utilizing a Commercial Rainwater Collection System
- Reduction in cost: In the long term, utilizing an on-site water supply can effectively reduce your water bills, electricity bills, carbon emissions, and potential urban development costs.
- Reduce dependence on public water supply: Rainwater can be used for domestic purposes, such as washing floors, plant watering, ecological pool replenishment, etc. This system can save the usage of tap water enormously.
- Balance the pH of groundwater near coastal areas: If the purified water recovered from rainwater integrates into the public groundwater in coastal areas, it will help moderate the salt content of groundwater and balance between saltwater and freshwater.
- Alleviate land subsidence: If rainwater recycling, can replenish groundwater. As a result, this will help maintain the groundwater level and reduce the risk of seawater intrusion in coastal areas.
- Boost the supply and demand of the rainwater recycling industry: By promoting the benefits of the rainwater recycling system, it can help the relevant sectors to achieve a more extensive economic scale.
The Considerations of Building a Commercial Rainwater Collection System
- Evaluate the on-site space for the system and the volume of rainwater storage. Assess the available area to see where and how can the rainwater recovery system work, which includes the water storage of the rainwater and purified water.
- Define the purpose of the commercial rainwater collection system: define the application of how the rainwater would be used. For example, domestic use can be flushing toilets, planting, and watering.
- Synchronize with the new project planning: If there are new construction projects, the rainwater recovery system should be considered in the construction planning to maximize its capability.
- Evaluate the waterway planning of the building: use the floor plans to plan out the waterway for the existing area and the potential impacts of changes. The considerations include water collection, drainage, other water sources, etc.
The Pre-planning of Building a Commercial Rainwater Collection System
- Add filtration and purification to the system: Consider extending the service life of water storage tanks and plant irrigation systems, it is suggested that the commercial rainwater collection system integrates with a desilter, leaf separator, or UV sterilization.
- Consider the blockage issue of plant irrigation: the plant irrigation system can have different spraying modes - full-automatic, semi-automatic, and manual. It is recommended to avoid fully automatic watering mode to prevent sediment from clogging the tubes.
- Separate the storage for different water resources: It is important to avoid pollution by mixing water resources in the same water pool. For example, tap water mixing with industrial pure water.
- Follow the relevant laws and regulations for the differentiation of water supply pipes: For example, in Taiwan, it is required that the surface of rainwater supply pipes should have a label every meter with the word "rainwater", adding the direction of where the water will flow to. In addition, if a rainwater pipe is going to expose outside, the tube should be colored green or at least painted green.
- Plan ahead the long-term maintenance plans: According to the application of rainwater, develop its maintenance process which can make a budget.
An Example of Building a Commercial Rainwater Collection System
Layana‘s headquarter is located in Lukang, Taiwan. The closest reservoir to provide local water is 104 kilometers far away. Moreover, this industrial zone is next to the coast, which makes it the factory more challenging to have water resources. Therefore, during the construction period of the factory, we designed numerous water tanks by creating a raft foundation in the basement, which has a capacity of more than 2,900 tons of water storage with an area of 135,948 square feet. The water pools can store various water resources - rainwater, purified water, tap water, and industrial water. The way that the factory collects rainwater is from the top floor which has holes in the floor to collect rainwater.
These holes have a layer that is a stainless-steel filter screen, which can filter containment such as leaves or stones. Then rainwater goes down to the collection tanks in the basement. The sediment in the rainwater collection tank will settle down over time, and the filtered water will go to a separate water pool. This filtered water can water plants and flush toilets. These rainwater collection pools can save up to 7,184 tons of city water every year, saving about USD$3,080 in water bills.
The rainwater recovery system has become the most outstanding feature of the headquarter.
Conclusion
Taiwan's agricultural period happened between 1953-1960, during the period, rainwater was a gift for farmers from God. Since the development of industrialization, rainwater has become a burden on the city. As societies progress, we can evolve the ways we use rainwater. Nowadays, we often face natural disasters caused by extreme climates. If we could build residential or commercial rainwater collection systems in cities or industrial areas, we can solve water shortages caused by emergencies and climate disasters. Let the rain that falls from the sky no longer regard as a burden for the city, but as a blessing.
The East Coast of Taiwan