As the cost of living rapidly rises, many Cape Town homeowners are feeling financially strained, and the cost of utilities is only increasing the burden.

According to analysts, the cost of water has increased by up to 400% in the last 10 years across many of South Africa’s municipalities,  not to mention the lingering water tariff in Cape Town following the drought. Besides the cost of water, concerns about ageing infrastructure and the possibility of future droughts, many South Africans have prompted many South Africans to seek alternatives to municipal water supplies. Rain water harvesting is one such solution.

In this blog, we’ll explore the concept of rain water harvesting, its benefits, how it works, and its practical applications for residents in Cape Town.

Rain Water Harvesting: Everything You Need To Know

What is Rain Water Harvesting?

Rain water harvesting involves collecting, storing, and utilising rainwater that falls on your property. This practice serves various purposes, such as reducing the need for potable water from municipal sources. The main objective is to make use of rainfall that would otherwise go to waste as surface runoff or evaporate. By implementing rain water harvesting, you can have a self-sufficient water source and lower the cost you pay for municipal water.

What is a Rain Water Harvesting System, and How Does It Work?

A rain water harvesting system allows you to collect and direct water to your chosen storage tank, where it can be used for various purposes such as irrigation, toilet flushing and more. This system typically includes the following key components:

1. Catchment Surface

The catchment surface is the starting point of your rain water harvesting system. It is the area where rainwater is collected. Common catchment surfaces include roofs, driveways, and patios, essentially any impermeable area. It is crucial for this surface to be smooth and clean to facilitate easy water flow. Rooftops are often the preferred choice as they offer a large and efficient area for collecting rainwater. As rainwater falls onto the catchment surface, it begins its journey towards becoming a valuable resource.

Rain Water Harvesting - Water Pipe and Filter

2. Gutters and Downpipes

To efficiently collect rainwater, it is important to have a well-designed rain water harvesting system in place. Gutters and downpipes are key components of this system, serving essential roles. Gutters are installed along the edges of your roof or catchment area to capture the runoff. They direct the collected rainwater into downpipes, which guide the flow downwards. Strategically placed downpipes ensure that the water is directed to a central point for further processing and storage.

3. Rain Water Storage Tanks

Rainwater that has been collected is then directed into storage tanks or cisterns. Rain water harvesting tanks are available in different sizes and materials, such as plastic, concrete, or metal. The size of your rain water tank will depend on your water requirements and the available space on your property. For properties with higher water demand, larger tanks are suitable, while smaller tanks may suffice for residential use. These tanks serve as reservoirs to hold the harvested rainwater until it is needed for various purposes.

Rain water harvesting - Storage Tanks

4. Filtration System

When collecting rainwater, it is important to note that it is not immediately suitable for use. This is because it can contain debris, dust, and contaminants from the catchment surface and gutters. To ensure the harvested rainwater is of good quality, a filtration system is required. A rain water harvesting system should include a water tank filter and screen that effectively removes larger particles, preventing them from entering the storage tanks.

In addition to the filtration system, a “first flush diverter” can be used. This clever device diverts the initial rainwater runoff, which typically contains the highest concentration of contaminants, away from the storage tanks. By doing so, it helps to ensure that the water stored is cleaner and safer for its intended use.

5. Pump and Distribution System

When you’re ready to use the rainwater, it needs to be transported to areas of your property. For this purpose, a pump and distribution system comes into play. The pump is responsible for pressurising the stored rainwater and allowing it to flow through pipes to where you need it.

Depending on your needs, this water can be distributed to outdoor taps for gardening, a separate plumbing system for toilet flushing, or even to your washing machine. The distribution system is set up to ensure that the harvested rainwater is accessible and ready for use whenever you need it.

Rain water harvesting - Water Dispensing with Bucket

4 Incredible Benefits of Rain Water Harvesting

If you have been wondering ‘what are the advantages of collecting rain water’, here are the 4 benefits of rain water harvesting for your home:

1. Rain Water Harvesting Conserves Municipal Water

Rain water harvesting offers a compelling benefit by helping to conserve municipal water resources. In areas like Cape Town, where water scarcity is a persistent challenge, every drop of harvested rainwater makes a significant impact. By using rainwater for tasks like gardening, car washing, and toilet flushing, you can decrease your reliance on city water supplies. This helps ease the strain on the municipal water supply, allowing it to be used for essentials such as drinking and cooking.

Rain Water Catching

2. Rain Water Harvesting Can Save You Money

Installing a rain water harvesting system is a worthwhile investment that will help you save money on your water bills. By collecting and utilising rainwater for non-potable purposes, you can save money that would otherwise be spent on municipal water. Over time, these savings can be significant, especially if your household has a high water consumption. It also provides protection against future price increases, securing your home’s financial stability through a free and plentiful water supply.

3. Rain Water Harvesting is Environmentally Friendly

Rain water harvesting is not only a cost-saving measure, but it is also an environmentally responsible practice. By collecting rainwater, you are adopting a sustainable approach to sourcing water and reducing the carbon footprint associated with treating and distributing municipal water. By participating in this practice, you are actively protecting natural water sources, supporting local ecosystems, and reducing the overall environmental impact of water consumption.

Saving Water

4. Mitigates Flood Risk

In Cape Town, heavy rainfall can result in localised flooding and soil erosion. When rainwater flows off paved surfaces and into stormwater drains, it can overwhelm the drainage system, leading to flooding in low-lying areas. To address this issue, rain water harvesting serves as a practical solution. By capturing and storing rainwater, you not only reduce runoff but also create a means of redirecting excess water to where it’s needed. This helps manage flood risk by preventing water accumulation in areas prone to damage, safeguarding your property and the surrounding environment.

Rain Water Harvesting: 3 Frequently Asked Questions

1. How Much Water Can Be Saved by Rain Water Harvesting?

One study conducted in Paris found that rain water harvesting efforts could save a total of 11% of potable water. The City of Cape Town estimates that the demand for water throughout summer in 2023/2024 will reach as much as 1200 million litres per day! Presuming the study’s estimation is correct, rain water harvesting could save 132 million litres of water per day in Cape Town alone!

As for your household, a family of four can use anything between 300- 800 litres of water per day or at a maximum of around 292,000 litres per year. Using the study’s estimate of 11%, this equates to 32 120 litres a year that could be saved by using rain water instead of municipal water!

That being said, the amount of water saved and collected through rain water harvesting depends on several factors, including the size of the catchment area, the frequency of rainfall, and the capacity of your storage tanks.

For example, different rooves yield varying amounts of harvested rainwater. A 100 square metre metal roof can produce 1,000 litres of rainwater with 11 mm of rainfall, while a tiled roof of the same size needs 16 mm of rainfall to generate the same amount. As you can see, roof type significantly affects rainwater collection.

Rain Water Tank

2. Is Rain Water Safe to Drink?

Rainwater, in its purest form, is a safe and essential water source for many communities worldwide. However, it’s important to acknowledge that not all rainwater is suitable for consumption. Various factors, both physical and environmental, can contaminate rainwater and pose health risks. Parasites, bacteria, and viruses can be present, leading to disease outbreaks.

Furthermore, rainwater collected in heavily polluted areas or contaminated with substances like animal waste or heavy metals may not be suitable for drinking. Therefore, it’s crucial to ensure the cleanliness and safety of rainwater before consumption.

In conclusion, while rainwater is not inherently unsafe, it’s recommended to exercise caution and prioritise your health by ensuring that the water collected from rain water harvesting is free from harmful contaminants.

3. Can I Collect Rain Water?

In South Africa, there are fortunately no limitations when it comes to the collection of rainwater and the installation of rainwater tanks. This allows you to collect and store this precious resource without any hindrance or regulations.

Collecting Rain Water

Rain Water Harvesting: 4 Common Residential Uses

Here’s how you can maximise the use of harvested rainwater in your home to save water and reduce your environmental impact:

1. Irrigation

Rain water harvesting is an eco-friendly option for watering your garden and plants. By using rainwater for irrigation, you can reduce your reliance on municipal water and promote healthier growth. It’s a natural, chemical-free source that improves soil quality and minimises the ecological impact of your landscaping. Harvest rainwater and direct it to your garden’s irrigation system to conserve potable water and support a sustainable garden.

Watering the Garden

2. Toilet Flushing

Toilets use a significant amount of indoor water. Reduce your environmental impact and save on water bills with rain water harvesting and a dual plumbing system. Using rainwater for toilet flushing is a practical solution. By diverting rainwater from storage tanks to toilets, you can efficiently use harvested rainwater for non-potable purposes. This conserves drinking water and promotes sustainable water management at home.

3. Laundry and Car Washing

Both laundry and car washing are tasks that do not require potable water. By using harvested rainwater for these activities, you can make a significant impact on water conservation. Connect the rainwater from your storage tanks to your washing machine and outdoor taps to wash your clothes and vehicles. This approach not only reduces your water consumption but also reduces your reliance on municipally treated water for tasks where rainwater is equally effective.

Car Washing

4. Outdoor Cleaning

Rainwater is highly suitable for outdoor cleaning purposes as well. It’s ideal for tasks like stoep, driveway, patio furniture, and outdoor equipment cleaning. By utilising rainwater for these activities, you can ensure that your property maintenance has a lower environmental impact.

Absolute Plumbing: Rain Water Harvesting Systems and More!

Rain water harvesting is an excellent solution to reduce your reliance on municipal water supplies and save both money and water. If you prefer not to install a rain water harvesting system yourself, our team of professional plumbers is just a call away. We offer expert assistance in choosing the most suitable system for your home, providing all the necessary equipment and ensuring a seamless installation on your property.

Besides rain water harvesting systems, Absolute Plumbing also provides specialised and general plumbing services in Cape Town. We can assist with leak detection, drain cleaning, pipe relining, bathroom renovations and more.

If you are ready to start saving money on your water bill through rain water harvesting, reach out to Absolute Plumbing today! Your search ends here; no need to keep looking for ‘plumbing services near me’ or ‘plumbers near me’ online. Absolute Plumbing is your trusted plumbing company, catering to all your plumbing needs. Give us a call at 084 872 2758 for a FREE quote!

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