Rainwater harvesting offers an affordable, simple, sustainable, and reliable alternative water source. Not only does rainwater harvesting supply water for indoor and outdoor use, it protects the environment from detrimental non-point source pollution by reducing rooftop runoff.
The water supply in South Africa today is very different than it was 100, 50, or even 25 years ago.
Our population continues to increase, while water supplies remained constant. The amount of water available today is the same amount of water that was available 100 years ago.
Since water is a finite resource, current and future plans must strive to maintain or improve available water quality while utilizing the available water resources as efficiently as possible.
Since only 2.5% of the world’s water is freshwater, ensuring that this small amount of available water is utilized efficiently and quality is maintained is a daunting task. This is becoming even more important as populations increase worldwide. A recent report by Credit Suisse stated that by 2025, 18 countries will experience water demand beyond supply capabilities.
Worldwide water consumption is rising at double the rate of population growth. Similarly Africa’s water consumption is continually increasing. Due to the increasing demand for public water supplies, groundwater levels are declining and municipal treatment plants are struggling to supply current demands while dealing with declining infrastructures.
Decentralized rainwater harvesting offers an overlooked alternative and sustainable water source.
Some countries like Australia, Bermuda, Germany, Belgium and India are requiring all new development in certain areas to be equipped with rainwater harvesting systems to preserve declining groundwater supplies. These regulations were made in response to the imbalance of population demand and available water supply.
Some US housing developments are even incorporating rainwater harvesting in their low impact development designs as means to reduce municipal water demand and deter storm water runoff. Furthermore, some municipalities had to restrict or prevented development in areas with insufficient drinking water supplies.
South Africa is considered an arid country and the increase in population is putting increasing demands on water supplies. As a result, planners, state officials, residents, and developers must look at alternative water sources to supply the demands.
Rainwater harvesting is ideal for large retail and industrial buildings, especially ones with expansive parking lots.
An industrial rainwater harvesting design starts with siphonic roof drainage. Rainwater is diverted from the flat roof to either an on-site storage tank(s) or pond. Stored water is then diverted both indoors and outdoors to be recycled for toilet flushing, linen washing, facility cleaning and irrigation. Not only does the company save water consumption costs, but it also reduces storm-water runoff on the site. The storm-water reduction aspect of rainwater harvesting holds this alternative water source above other alternative sources because rather than contributing to pollution through salt discharge (desalination) or energy consumption, it is reducing pollution and protecting local waterways.
Acting proactively to protect the environment and conserve resources is beneficial today and tomorrow.
