Monday, November 20, 2017

Rain Water Harvesting

Water-saving and rain harvesting

A report released in early October 2009 by the Water Research Commission of South Africa found that South Africa has 4% less water than 20 years ago.

Rand Water is predicting that demand for water in South Africa will outstrip supply by 2025. It also believes that Gauteng is potentially facing a water shortage as early as 2013. In Cape Town the scenario is not much better, with a water shortage prediction by 2016.

This means that, if South Africans continue with their wasteful water practices, there simply will not be enough water to meet the country's future needs and, more importantly, we may have to start paying even more for water. However, Rand Water and the Water Research Commission of South Africa's project director, Brian Middleton, notes that South Africans can change the scenario by changing their behaviour towards water usage. We need to become water wise and savvy about rainwater harvesting.

So what is rainwater harvesting?

Rainwater harvesting is the term used for the collection, storage and distribution of rainwater. This water can be used anywhere you use tap water. The idea of using drinking water to flush our toilets and water our lawns is wasteful and irresponsible, especially in light of the population growth and water shortages across the country. And, rainwater collection greens your home and lessens your environmental footprint.

The many benefits of rainwater harvesting

There are many benefits to rainwater harvesting, including:
• It is an absolutely free source of water.
• Water stored in water tanks provides you with water security when the municipal water is cut off for any reason whatsoever.
• It reduces flooding and erosion caused by storm water run off.
• Rainwater harvesting is environmentally responsible.
• A rainwater harvesting system can be easily retrofitted to an existing structure or built during new home construction.
• The process uses simple technologies that are inexpensive and easy to maintain.

How much can you harvest?

Just 1mm of rain allows you to harvest one litre of water per 1m² of roof area – simply by ensuring that your gutters are installed to direct rainwater to rainwater tanks. An annual rainfall of 500mm on a roof surface of 50m² amounts to 25 000 litres of usable water that can be preserved (40 litres per day for 625 days). In South Africa, the water allocation per day per person is 25 litres. Water tanks, such as JoJo tanks for example, are available in a variety of sizes, from 260-litres to 20 000-litres.

Things to consider when investing in a water tank

• When you purchase a water storage tank, make sure that it is completely sealed to prevent evaporation and mosquitoes from breeding. Naturally, you will need to provide for an inlet pipe or gutter.
• Make sure that the tank has a filter to catch leaves and twigs that flow down the gutters, and that it has an over flow.
• Make sure the tank has a guarantee – top brands usually come with a five-year guarantee.
• Only the best raw food grade material should be used to ensure that the tanks can withstand the harshest South African weather conditions.
• The tanks need to be UV-resistant and lined with carbon black to stop algae growth and ensure that the stored water remains clean.

Other ways to save water

Look out for leaks: Leaking taps, toilets or pipes can waste a huge amount of water over a month – check them out and have them fixed as soon as you can. To ensure that you have no water leaks, check your water meter last thing at night, and then again first thing in the morning. If nobody used any water during the night, the meter dial should not have moved. If it did, it means you have a leak. To check your toilet, put a few drops of food colouring in the cistern and don't flush it for about an hour. If colour appears in the bowl, it means there is a leak.

Install a dual-flush toilet: It is estimated that new dual-flush toilets can use up to 66% less water than single-flush cisterns, and 30% less than older, dual-flush models.

Fit tap aerators: These are easy and inexpensive to install and can cut the flow of water from your tap by up to half without reducing water pressure – so you won't even notice the difference.

Only switch the dishwasher and washing machine on when they are full: Running your dishwasher with a full load will generally use less water than washing the same number of dishes by hand in the sink. Similarly, washing machines are at their most water-efficient when they have a full load.

Shorter showers: It is common knowledge that showering is far more water-efficient than bathing. However, reducing the amount of time you spend in the shower is another very effective way of saving water. Try and keep your shower to around four minutes if possible.

– Antonella Dési