It may seem as if we are surrounded by an endless supply of water, however, with only 1% of the global water available for human use, it’s a far more finite resource than means the eye. Managing water use is essential; It helps to sustain municipal water supplies and saves money on water use too. Recycling and reusing rainwater is an excellent technique for water preservation, especially in countries like the UK that face heavy rainfall yearly (avg. 1432 millimetres PA according to statista[i]). On the reverse, the average person in the UK uses about 142 litres of water a day. [ii]Sustainable, environmentally friendly and financially responsible, rainwater harvesting is one of the most efficient means of saving tap water for menial household and garden tasks.
Can You Drink Rainwater?
Drinking rainwater may seem like something out of a survival film but it is a genuine solution with some treatment. It’s certainly not advisable to just stick your head under the tap of your water butt when you’re thirsty. As it falls from the sky and runs over roofs on its way to the pipe, the water can easily pick up bacteria and viruses, as well as heavier sediments and minerals. All the contaminants picked up in the process render the water unsuitable for human consumption.
You can treat the water ready for drinking or cooking by properly filtering the water. One method of achieving this is by distillation or using a proper water filter, such as a UV filtration system, to prepare the water for human consumption.
Bathing and Laundry.
One of the most efficient, multi-beneficial methods of using rainwater is bathing and laundry. Rainwater is naturally soft (fewer minerals such as calcium and magnesium). This makes it easier for soap and detergents to dissolve. Washing hair with rainwater has great results, due to the neutral pH and lack of heavy metals. As well as hair, using rainwater to wash is beneficial for people who suffer from sensitive skin.
Rainwater is good for your washing because the detergent dissolves much easier. With hard municipal water, a lot of detergent you use remains in your clothes or down the drain. The build-up of soap residue can lead to clothes going grimy and discoloured.
Rainwater for Toilet Flushing.
People in average in the UK use 34.4 to 71.2 litres a day flushing the toilet. This is a staggering amount, with the average flush using 6-13 litres of water. This accounts for a third of daily water usage in UK households and the single biggest use of water in UK households.[iii] Granted, flushing the toilet is not something that can be avoided, but we can limit the amount of fresh water supply used by manually flushing with rainwater.
Collecting run-off rainwater for flushing presents a solution for the overuse of precious municipal freshwater supply, taking pressure off such a vital system.
Watering Gardens, Lawns, and Houseplants.
Rainwater is better for your plants than tap water. After all, plants would naturally rely on rainwater for their survival, so it makes sense to save your rainwater for use in your garden. The minerals in tap water can raise the pH of the soil around the roots, affecting the ability of plants to absorb nutrients. The acidity of rainwater raises the pH of the coil, releasing the micronutrients such as zinc and iron that are so essential for plant growth.
Another benefit of rainwater is that fewer salts reach the roots of plants. This salt build-up, just like the build-up seen in kitchens and bathrooms, can lead to water being rejected by plant roots. In addition, increased oxygen levels are beneficial for plant growth.
Plants outdoors naturally get exposure to natural rainwater, but houseplants love it too. Saving rainwater for this purpose benefits your plants and saves tapwater.
Washing your car
It will come as no surprise to anyone that washing cars are an extremely water-intensive process. Hosepipes use 10 litres per minute on average, meaning a car owner can easily go through a whole day’s household water consumption in one car wash. The purified tap water is wasted in this process.
Using rainwater has a twofold effect, not just creating efficiency with water use. Streaks and spots are less likely to make your car look as dirty as before it’s clean due to the absence of sediments, minerals and salts in the water.
As well as the five efficient uses mentioned above, there are more ways rainwater can save tap water. Water features and fountains work well with rainwater due to the absence of minerals and sediments that can block up pipes and prevent them from operating. It also has a good chemical build-up for use in composting, making it perfect for pretty much everything you find in most gardens.
Employing these tactics is a fantastic way to limit tap water use, in areas where rainwater may even be more effective for the purpose. For plants and washing, rainwater is ideal due to its natural properties, and the absence of minerals and sediments that would be otherwise harmful. For other purposes where treatment is needed before use, good water filtration such as UV sterilisation would make efficiencies in the long term (despite the initial costs).