We might take it for granted, but water is one of the most precious and scarce natural resources on our planet. Awareness has steadily been on the rise with respect to the importance of water to our survival, especially in a dry country such as South Africa. Take a look at the advantages of rainwater harvesting and why you should consider it.
What is Rainwater Harvesting in South Africa, and Why is it So Important?
Harvesting of rainwater is simple. It involves the collection of water from rainfall and collecting the water for use. Typically, water is collected from places such as the roof of a building, then stored for later use. In rural South Africa, this is a very common practice. Dams are also a method of rainwater collection and are an excellent method of collecting groundwater runoff. Regardless of how it’s collected, all water is precious.
Read more on grey water recycling systems.
Rainwater Harvesting Techniques
Although it’s commonplace in rural South Africa, rooftop rainwater collection can also take place in urban and semi-urban areas as well. All that needs to be in place is a gutter on the roof that directs the rainwater down a tube which connects to a rainwater collection tank. If you’re doing this, you’re playing a huge part in water conservation. Water collected in this way can be stored and distributed for a variety of uses.
Collected rainwater is especially important to those who aren’t in the city water supply. If you’re a city-dweller, it is indeed possible to trade a substantial amount of your water usage for collected rainwater. It’s possible for a large portion of South African households to be largely self-sufficient with respect to rainwater collection and usage.
What Are the Benefits of Rainwater Harvesting?
Rainwater harvesting is a way that we can significantly reduce our reliance on certain types of infrastructure, such as water storage dams. This will significantly increase the lifetime of these dams by placing less stress on them. Also, this will reduce the need to construct new dams. You’ll also be able to significantly reduce your water bills if you collect rainwater.
Another important aspect of rainwater collection is the negating of storm water system overload. When water is captured and recycled for residential use, less water goes into the storm drains. This reduces the risk of floods and other natural disasters that can wreak havoc in communities and neighbourhoods.
What About Dirty Roofs?
If you’re worried about a dirty roof impacting the quality of your rainwater, don’t! There are plenty of ways to bypass this, particularly by the means of a device called a first flush device. This device diverts the initial flow of water away from the rainwater tank, decreasing the likelihood of rooftop contaminants being present in your collected rainwater.
Sizing of Rainwater Storage Tanks
An educated decision must be made regarding the appropriate size for your household’s usage of a rainwater tank. Once the environmental factors are taken into consideration, it’s possible to make a largely informed decision pertaining to the suitable storage capacity of a rainwater storage tank. You’re going to want to consider factors such as rainfall, data, storage performance, and storage capacity, to decide what size water collection tank you’ll need to purchase.
Water Balance for Estimation of Rainwater Storage Capacity
You’ll want to know the area of the roof from which you’ll be collecting your rainfall. The larger the area of the roof, the more rainfall that will be collected.
Assessing Performance of Different-Sized Rainwater Storage Tanks
The performance of an individual water-collection tank is largely centered around its daily water storage capacity. This can be derived from a simple calculation, one that takes into account certain factors, such as rainfall. Make sure you know your storage capacity before you buy your tank!
The storage capacity is computed using a computer model. The model will take daily water balance calculations into account. This includes runoff generated and the daily level status of water storage.
The weather isn’t the most predictable natural phenomenon, and the anticipated storage levels can overflow or be dry. The water must be supplied from other sources, in this case, to meet demand. The aforementioned computer model also takes in to account the exact differences needed if the above scenarios were to present themselves.
Capturing Ground Runoff
Rainwater harvesting certainly isn’t limited to roof catching. Ground runoff can also be a factor that impacts the total water balance of an equation used to calculate storage capacity of a rainwater tank. The computer model can also take into consideration the handling and flow of the water, accounting for minute gains or losses. A lot of factors are taken into account when it comes to ensuring sustainability of our most precious natural resource.
Read more on harvesting rainwater in South Africa
Advantages of Rainwater Harvesting
Easy to Maintain: There are certain community advantages that come with rainwater collection. Firstly, rainwater harvesting allows us to sustainably reuse a precious resource. Drinking water is not renewable, which makes this practice of utmost importance. Systems for rainwater harvesting are simple.
The entire cost of the installation and operation of rainwater harvesting equipment is extremely cheaper than the likes of a water purifying system, for example. There are little time and energy required for the maintenance, and substantial results can be visibly seen without purification
Reducing Water Bills: This is a no-brainer. Water that’s harvested through rainwater can be immediately used for several, non-drinking water functions. This can ultimately lead to huge reductions in utility bills for both businesses and residential buildings. When it comes to industrial buildings, harvesting rainwater can provide the perfect amount of water to reduce any operation’s operating costs, ultimately saving a ton of money. There is also the added bonus of not having to use the nearby water sources extensively, especially with respect to farms.
Soil erosion is significantly reduced, as well. The land will thrive on recycled water. This water can be used whenever necessary; storage is simple and easy!
Suitable for Irrigation: Save money on building expensive, natural water irrigation systems! Forget the new infrastructure. Stemming mainly from rooftops, rainwater harvesting can be a sufficient supply for any irrigation system. You’ll also save money on fuel, by having to use less machinery.
Rainwater is free from a lot of chemicals that are commonly found in most purified water. This alone makes it suitable for irrigation as well as many other things. Storing large collections of rainwater and other harvested water is a great way to help eliminate forest fires if you live in an area where forest fires are prevalent!
Reduces Demand on Groundwater: With a rapid increase in our planet’s population, demand for water is also increasing. The result of the increasing demand for fresh water is that industries and communities alike are forced to dig down to aquifers to satisfy their operational demands. Groundwater has become increasingly scarce, because of this. In areas that have large water scarcities, this can be of particular danger.
Reduces Floods and Soil Erosion: During any rainy season, rainwater is harvested in immensely large tanks, reducing the risk of flooding in areas which are prone to it. Soil erosion is also alleviated through rainwater harvesting because of the lack of acid rain runoff in both lakes and ponds.
Can be Used For Multiple, Non-drinking purposes: Rainwater that’s harvested can be used for a variety of non-drinking purposes, such as flushing toilets, gardening, washing clothes, and washing cars. Why use pure drinking water when you can use what the sky provides, with the same effect?
Disadvantages of Rainwater Harvesting
Unpredictable Rainfall: Nature isn’t the most consistent, especially when it comes to rainfall. Rainfall can be hard to predict. Sometimes, little to no rainfall can completely halt the collection of sustainable rainwater harvesting. Rainwater area is primarily suited to areas that have moderate to high levels of annual rainfall
High, Initial Price: Although some can be cheap, many rainwater harvesting systems can be hugely pricey at first. Although they pay for themselves in the long run because of the eventual utility bill reduction. The long run is usually ten to fifteen years.
Regular Maintenance: Rainwater harvesting systems can be tiresome to maintain. Depending on where you live, many types of rainwater harvesting systems can be prone to many types of pests. If they aren’t maintained, they’ll become the breeding ground for a plethora of unwanted animals.
Rooftop Chemicals and Animal Droppings: You’ll never be totally certain of what is on top of your roof. Certain rooftops may be prone to chemical accumulations as well as bird droppings. Know the risk of what you’re installing before you pollute your plants or car!
Storage Limits: There is a limit to everything. Even when it comes to the amount of rainwater a system can hold. Unless you own a reservoir, rainwater collection systems can be prone to overflow, if the season is particularly wet.
Rainwater harvesting is relatively new but is gaining a decent amount of traction. Areas the experience large volumes of rainfall will benefit greatly from harvested rainfall. Dry areas will be able to experience the rainfall harvested if it’s distributed to these areas. The benefits of rainfall harvesting cannot be overlooked, regardless of where you live!
Read more on living life in the green zone.