How to Go Off-grid with Water
PUBLISHED 5 DEC 2016
Namibia is a hot, dry country that experiences extended periods of drought. Consequently, water is a commodity that is in short supply and high demand, resulting in it being both scarce and expensive.
Yet homeowners can implement measures to tide them through dry periods by harvesting rainwater. This will help them become more self-sufficient and maybe even enable them to go off-grid completely with water.
However, before you can do away with your municipal water supply, you need to find a source of water that will be able to supply your household's water needs. If you are fortunate enough to have a stream or spring on your property you can tap into this; alternatively, you can dig a borehole to access groundwater. But for homeowners that don't have the luxury of onsite water, which includes most urban homes, rainwater collection is the obvious solution.
Becoming self-sufficient with rainwater is possible in both a rural and urban setting, as rainwater can be collected wherever there is rain — even in arid areas such as Namibia that receive very little rainfall.
Rainwater Collection and Storage Systems
Roof surfaces are typically used for rainwater collection — this can be the roof of your house, outbuilding or even the roof of a carport or similar structure. However, water can also be channeled from other surfaces, such as driveways, to underground water storage tanks for future use.
This stored water can then be used in and around the home for multiple purposes, including watering your garden, washing your car, or keeping your pool topped up. It can also be used for domestic household use, as well as a source of drinking water for both you and your pets.
A typical rainwater harvesting setup is comprised of several key components:
Catchment surface — this is usually a roof structure, but rain can be collected from any surface, including decks, patios, and driveways.
Diverter — this diversion system channels the rainwater that has been collected into your storage tanks
Storage tanks — these can consist of rainwater barrels or an underground cistern that store the water for later use, as and when you need it
Distribution network — the distribution system comprises the network of water pipes that distribute the water from the storage tanks to garden or home, providing water where it is needed.
Water treatment system — depending on what you intend to use the collected water for, it may need to be treated. This usually involves a pre- and post-storage filtration system, and possibly also further treatment, if you plan to use it as a source of drinking water.
When purchasing water storage containers for your rainwater harvesting system you need to make sure they will not pose a health or safety risk. Rainwater storage containers must close properly to ensure that children, pets or wild animals cannot accidentally fall into them. If the collected water is a source of drinking water the tanks must be manufactured from materials of food-grade quality that will not leach dangerous chemicals into your water supply.
Above-ground rainwater storage tanks are popular among homeowners in urban areas. There are many different sizes, colours, and shapes to choose from, which allows the homeowner to find a solution that will not only fit into a specific space in their garden but also look good in the space, blend into the backdrop of a wall or the garden's natural colour scheme.
Above-ground or below-ground cisterns provide another storage solution for harvested rainwater. Below ground cisterns offer the perfect solution for storing large volumes of rainwater without occupying valuable garden space in suburban gardens. Smaller, lightweight, portable above-ground cisterns are also available and are an excellent choice if you are wanting a water storage tank that is a bit more mobile.
Harvested rainwater can be used for multiple purposes around the home, including drinking water. In fact, compared to other sources of water, rainwater contains no harmful pathogens or contaminants as these were removed during the evaporation process. However, contaminants such as grit, particulate matter, and debris, as well as any chemicals that may be lingering on your collection surface, can be washed into the water storage container to contaminate the water stored within. To prevent the harvested rainwater from becoming polluted by external contaminants you need to ensure that there is a pre-storage treatment filter fitted to stop these contaminants from entering your water storage system. If you plan to use the water as a source of drinking water, an after-storage water filtration system is recommended to ensure the water is completely safe to drink.