RAINWATER HARVESTING SYSTEM, a complete guide

What is a Rainwater Harvesting System (RHS)?

A rainwater harvesting system is the process or technology that enables houses and buildings to A gather and store rainwater for occupants’ domestic use. Good example ranges from simple rain barrels to more complex constructions with pumps, tanks, and purifying systems to produce potable water.

General Purpose of Harvesting Rainwater

DOMESTIC USE 

In addition to rainwater being able to be purified for human consumption, the non-potable water can be utilized for car washes, laundry, toilet flushing, and landscape irrigation. 

HELPING THE COMMUNITY

Due to water shortage becoming a major issue in many densely populated locations, rainwater harvesting systems can provide homes and businesses with water during dry seasons, thereby reducing the demand on the municipal level. 

ENVIRONMENTAL IMPACT

Rainwater harvesting is an important component of sustainable development as a whole. Encouraging the wise use of water resources and minimizing the environmental impact of human activity, it is consistent with the ideas of sustainable living. 

USES OF HARVESTED NON-POTABLE RAINWATER

Looking Back: A Brief History

The construction and use of cisterns to store rainwater can be traced back to the Neolithic Age, when waterproof lime plaster cisterns were built in the floors of houses in village locations of the Levant, a large area in Southwest Asia, south of the Taurus Mountains, bounded by the Mediterranean Sea in the west, the Arabian Desert in the south, and Mesopotamia in the east.

Many ancient cisterns have been discovered in some parts of Jerusalem and throughout what is today Israel/Palestine. people dug and carved out cisterns out of solid rock during the dry summer months to contain large amounts of water from the rainfalls. Cisterns were domestic gathering places and centers of life in the Near East, and sometimes the object of strife.

ANCIENT CISTERN RUINS FOUND IN PALESTINE

Importance and Benefits of RHS

1. One comparatively clean and cost-free source of water is rainfall.
2. Your water supply is completely under your control, which is great for cities with water restrictions.
3. The system is environmentally compliant and socially acceptable.
4. It encourages sustainability and aids with water conservation.
5. Rainwater is more preferable than chlorinated water for gardens and landscape plants.
6. Stormwater discharge from residences and businesses is decreased.
7. It can give you free water and resolve any drainage issues on your home.
8. Straightforward, low-cost, and easily maintained technologies are used.
9. It can serve as both a primary and a backup supply of water for municipal water systems and wells.
10. The technology is simply installed during the construction of new homes or retrofitted into an existing building.
11. Systems are very adaptable and can be modular, enabling relocation, reconfiguration, and enlargement when needed.
12. It can offer a reliable backup supply of water in an emergency.

Basic Components of RHS and How it Works

Types of RHS in terms of Collection Methods

BARREL TYPE

This is the most often used approach, and it is well known to most people. To collect rainwater, this entails putting a barrel at a gutter downspout. The actual barrel could be a brand-new, commercially manufactured rain barrel or one that has been repurposed. Rainwater collected can usually be transferred by the scooping method or by installing a faucet at the bottom.

Pros:

Anyone can easily do this at home.

You can easily find barrels in your neighborhood or online at a number of different retailers.

Barrels can be used in any setting because they don't take up much room.

Cons:

Usually, capacity ranges from 50 to 100 gallons.

Overflows readily and squanders gathering possibilities

In case you decide to go for the barrel-type RWHS, you might want to try this accessories and fittings kit.

DRY SYSTEM

This setup is similar to a rain barrel setup, but it requires more storage space. Since the collection line empties straight into the top of the tank, it essentially "dries" after every rain event.

Pros:

able to hold a substantial volume of rainfall

Ideal for regions with sporadic rainfall and heavy storm activity

Can be implemented at a low cost

simpler system means easier upkeep

Cons:

The location of the storage tank must be next to your home.

WET SYSTEM

Using this method, you can link many downspouts from various gutters by burying the collection pipes. Rainwater will fill the subterranean pipes, rising through the vertical pipes and overflowing into the tank. Watertight connections must be made between the subsurface collection piping and downspouts. The tank inlet's elevation needs to be lower than the house's lowest gutter.

Pros:

The capacity to gather information from your whole collection surface

The capacity to gather from several drains and gutters

The tank may be situated distant from your residence.

Cons:

More costly to install because of subterranean plumbing

There must be a sufficient gap between the tank inlet and the gutters.

Modern Technology and Innovations

UV-RESISTANT STORAGE TANKS

In order to increase efficiency and broaden applicability, modern rainwater collection techniques include cutting-edge technology. Among them is the use of premium, UV-resistant storage tanks to guarantee long-term water storage and inhibit the formation of algae. The materials and designs of gutter and downspout systems have also changed, resulting in fewer obstructions and less upkeep needed. 

UV STERILIZATION AND FILTER SOLUTIONS

The use of collected rainwater for drinking has become possible due to significant advancements in water filtration technologies. To guarantee the safety and quality of the water in your rainwater collection system, some suppliers offer UV sterilization and filter solutions that can be incorporated into your projects.

What law Regulates RHS in the Philippines?

The law that currently regulates rainwater harvesting systems in the Philippines is what is commonly known as THE PHILIPPINE GREEN BUILDING CODE, issued June 2015, as A Referral Code of the NATIONAL BUILDING CODE OF THE PHILIPPINES, PD 1096, under Section 11.2. However, such provision covers only that of non-potable purposes. Potable water regulated by other government agencies will not be discussed.

Implementation and Execution

PLANNING AND DESIGN CONSIDERATION: Thorough planning is the first step, and it entails determining the capacity and requirement for rainwater gathering. This comprises figuring out the average rainfall, calculating the catchment area, which is typically the rooftop, and figuring out how much storage is needed depending on usage requirements. It's also critical to take the local weather and environment into account. Water safety and durability should be taken into consideration while choosing materials for the collection surface, gutters, and storage tanks. In keeping with the intended application, the design must also incorporate suitable filtration and purifying systems consulted with the experts.

INSTALLATION PROCESS: Installation comes next after the design. Firstly, determine the catchment area, which is typically the rooftop that usually exists. Installing or modifying gutters and downspouts is necessary to properly direct water into the storage system. To stop leaks and blockages, care must be given to make sure these parts are properly aligned and fastened. The location of the storage tank, which may be above or below ground, should take safety, maintenance, and user accessibility into account.

MAINTENANCE: RHS are known for requiring little upkeep, so with little

effort, you can still contribute to the long-term success of your installed system. This entails clearing the debris from the catchment area and gutters and inspecting the prefiltration, which may taint the water or create obstructions. It is important to routinely check the storage tanks for leaks, fractures, or the growth of algae. Regular inspections are also necessary to maintain the efficiency of filtration and purification systems.

Application

It is important that we be aware of our responsibility to the environment that we live in. One of the best ways to do this is through water conservation that can be practiced by applying the system of Rainwater Harvesting, not only in our own residences, but also in our farms and livestock. In this way, we can create a sustainable, self-sufficient living, as we revive on Earth. 

We have prepared a quick study to include affordable materials, sizes, and prices, handy for our reference. It would be much cheaper to use DIY methods rather than purchase sophisticated RHS components.

Final Thoughts

Water is a naturally occurring resource that is virtually free. Global population growth is driving rising demand for treated water. A balanced supply and demand for water may be maintained by using it responsibly. The most common and environmentally friendly method is to use a Rainwater Harvesting System in both residential and commercial structures for both potable and nonpotable uses. This could lead to a more ecologically responsible way of life by reducing the strain on the processed supply water. On a smaller scale, all these processes and technologies are always applicable here in the Philippines. It should begin in us.

Therefore, once we have completed a project like this, let us share our experiences to promote awareness on the subject of Rainwater Harvesting Systems. Our goal is to reach out to the world and show that we care.

CITATIONS AND PHOTO SOURCES:

https://en.wikipedia.org/wiki/Rainwater_harvesting

https://www.britannica.com/technology/rainwater-harvesting-system

https://www.dpwh.gov.ph/dpwh/references/laws_codes_orders/pgbc

https://pinoybuilders.ph/rainwater-harvesting/

https://rainwatermanagement.com/blogs/news/rainwater-harvesting

https://www.watercache.com/education/rainwater-harvesting-101

https://bible-history.com/biblestudy/ancient-cisterns#google_vignette

https://jewishaction.com/content/uploads/springs.jpg

https://yogishenna.com/gutter-price-list/

https://jomprice.ph/pvc-pipe-price-list/

JOEY CASTANEDA

Architect

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