Rainwater Harvesting and Reuse
Rainwater harvesting or as it is known by its other names; rainwater collection or catchment is simply the collection of runoff from structures built for the purpose or taking advantage of surfaces impenetrable by rainwater and channeling or putting same into storage containers or vessels for reuse purposes.
The most common or traditional method by which this is done is by collecting water on the roof of the building which collect in gutters and flow through/into downspouts or pipes; in order to make the collection easy and tidy. The alternative is to collect the water off serrated roofs with multiple containers and manually empty them into storage cisterns or tanks. The former method is easy, can be arranged for when the house is being roofed and does not demand extra manpower, the latter is more demanding and messy.
While rainwater is more commonly harvested or collected on farms and in developing countries, there seems to be a reemergence of rainwater collection to augment for water supply from municipal, regional or more conventional sources especially as the effects of global warming and climate change begin to affect underground water tables and the pollution of fresh water sources by saltwater floods.
It is also being exploited again because of its natural benefits to plants; lawns and gardens and of course to humans as well; absence of chlorine, natural pH and hydrogen levels not to mention the fact that it is free. How to collect this water and its importance is discussed in this eye-opening article.
Importance of Rainwater Harvesting
While the importance of rainwater harvesting has been classified into niches by most writers, here we will have a general rundown to ensure that general idea is gained without losing the quality of the message.
Bill Reduction: having money does not mean it has to be spent. Thus, by harvesting rainwater, it contributes to reducing the bills for the month especially in the rainy seasons and rainy climes. Due to the decline in underground water resources and the resultant increase in water bills, properly and harvesting rainwater reduces the dependence on billed water supply and directly reduces the amount of money paid on water bills.
Furthermore, by collecting rainwater, it reduces the strain on electric power used in pumping and treating water where this is provided personally. It therefore directly reduces the cost of bills paid on electricity.
In certain places such as Atlanta where Green House certifications such as LEED (Leadership in Energy and Environmental Design) are available for houses that engage and use greenhouse initiatives, rainwater harvesting has the effect of easing the process and enabling easy access to this certification and ensuring that the landlord is able to draw more rent due to their increased rating as a result of the certification – irrespective of whether it’s a commercial or a residential building.
All these ensure that a building that harvest rainwater in the long run either saves money or makes money from the effort and in light of the new economic realities, little cents and dollars being cut from anywhere is a great effort in the grand scheme of things.
Water Conservation: this is one very obvious advantage of rainwater harvesting. By harvesting rainwater, the strain that is put on public water supply is reduced and ensures it lasts longer. This is even more where the rainwater is piped into the building’s water supply. It ensures that the water (rainwater) is readily available and reduces the need to depend on the public water supply until it becomes very necessary.
Reduction of erosions in dry areas: generally, in areas where the populace is averse to the rainwater harvesting, it is likely you’d realize that the environment in those areas are more eroded due to the excess water running around and beyond the control of lawn and drainages and sewage systems. Before these waters return to the traditional methods of water control, it usually must have already had its negative effect, flood inclusive.
On the other hand, by raising the collection or harvest of rainwater, the direct effect is the reduction of the quantity of storm water runoff which directly helps in reducing the amount of water available which could contribute to erosion and all its resultant effects. This is on an individual level.
At regional or municipal level, an area that has high rainfall and suffers erosion as a result can come up with a plan that enables it to collect most of the rain that falls through runoff systems installed for the purpose to limit the amount of rainfall that touches the ground thereby augmenting municipal or regional water sources while at the same time ensuring that the problem of erosion is curbed.
Cleanliness: rainwater is purer when compared to treated water sources. This is not unconnected with the presence of chlorine and fluoride in treated water. Furthermore, rainwater being natural have and maintains a balanced pH level with results in it being more acceptable and healthy to plants as well it being softer which makes it more receptive to soaps and detergents, making washing and cleaning easier.
Maintenance: this is also an obvious advantage of rainwater harvesting in that it is easier for an individual to maintain his personal storage equipment; tanks, cisterns and pipes, with control of how often he wants them cleaned and with what than it is for the same individual to determine how well regional and municipal water authorities maintain their facilities. This puts control of the harvesters health firmly in his hands as against in an unknown person’s hands.
Disadvantages of Rainwater Harvesting
Health risks: this is easily the biggest disadvantage of rainwater harvesting. Since the most easily used collection point for rainwater is the roof, it goes without saying that the exposure of the roof poses a health risk as animals could leave droppings which are washed into the collection gutters by the rain, collected into the storage cisterns and tanks and stored and reused. There is also the fact that depending on which material the roof is made off, even rust could be washed off the roof and into the storage with definitely poses health risks.
Furthermore, rainwater, except in rare instances, is collected in an untreated state and stored in the same manner. Bacteria that collected in the water when left untreated could pose a substantial health threat to the users of the water.
Here, the possibilities are endless. In a household, there are basically 3 ways in which rainwater could be reused effectively and they are;
Agricultural uses
Potable use for the whole house
Non-potable house use
Agricultural or irrigation uses: this includes but is not limited to hand watering of lawns and gardens (flower and vegetable) with the rain water since we’ve established that rainwater is quite beneficial to plants because of its balanced pH and hydrogen levels.
Furthermore, where the expanse to be watered is large and can’t be conveniently watered by hand, the rainwater cistern or tank can be rigged into the sprinkler or irrigation system to ensure that what is being used on the plants is strictly rainwater for purpose of its benefit. It can also be used in washing/bathing the family pets without worry.
Potable use for the whole house: when properly filtered, there is nothing that says rainwater cannot be conveniently used in all corners and for all functions of the house. It could be used in cooking, bathing, brushing and all such other operations for which just any water won’t do. Where collected in commercial settings, it could also be used to replace regional or municipal provided water in industrial processes.
Non-potable house use: this includes using it to fill fountains and ponds. It can also be used in washing outdoor equipment and spaces like farm implements, cars, drive and walkways and garages.
How to Collect the Water
There are basically two systems by which rainwater is collected. The first the simple method only requires that there be a means to channel the water from a runoff (say a roof), through gutter and downspouts and into the receptacle. This method is recommended where the water will be used for strictly non-potable uses as water collected by this means is considered grey water and is not safe for potable uses.
Where the water collected in intended for more, then even the system by which it is collected has to be more. This is commonly known as the Complex system/method. While the runoff in this method may be similar to that in the simple method, this method is required to have a system that filters out debris and filth out of the water and a storage tank that keeps sunlight away from the water as sunlight encourages the growth of algae in rainwater.
By filtering properly and storing carefully, the water can be considered pure and can be used for all intended purposes including potable ones.
Much like fashion, rainwater harvesting went out of vogue and has made quite a good rebound. With the advance in technology and with climate change shifting what we know as the norm, rainwater harvesting may just be that missing piece to sustainable, cheap/free water supply we crave.