Rainwater harvesting is gathering and storing rainwater. It has been used to provide drinking water, water for livestock, and water for irrigation or to refill aquifers in a process called groundwater recharge. Rainwater collected from roofs can make an important contribution to the availability of drinking water. Water collected from the ground, sometimes from areas which are especially prepared for this purpose, is called Storm water harvesting. In some cases, rainwater may be the only available, or economical, water source. Rainwater harvesting systems can be simple to construct. Roof rainwater can be of good quality, it can be useful in flushing toilets, washing clothes, watering the garden and washing cars; these uses alone can cut typical house hold usage in half. An average house has potential to collect great amounts of water. One way to visualize the amount of water that can be available is one inch of rain falling on a thousand square feet of roof yields six hundred and twenty five gallons of water. In areas where ground water is not accessible rain harvesting is an excellent way to maintain life. It is also in some cases more economical than well drilling. Because of urban sprawl rainwater catchment has become an important way to help with run off pollution and aquifer recharge. If you can visualize that before a house was built or a parking lot was laid that area was a forest. The forest slowly absorbed the rain fall and released it into the ground. As the water travels through the earth’s layers it is purified. This purified water is stored in underground aquifers and released into springs and rivers, evaporates and begins the cycle over again. Installing a rainwater collection system helps to act as the forest once did. The effects of modern development are showing devastating effects on our clean water supplies. As water travels across parking lots and other surfaces it picks up pollutants. This now contaminated water is released strait into rivers and streams. Using rain catchment systems to store water in cisterns makes a great impact on stopping some of this surface water pollution. Using this collected rainwater for irrigation gives it a chance to slowly release into the earth then going back to its natural cycle. It is our responsibility to protect this most important natural resource.
An advantage in urban areas is that rainwater harvesting can assure an independent water supply during water restrictions. Rainwater reclamation is of acceptable quality for household needs and renewable at acceptable volumes despite forecast climate change. It produces beneficial storm water management and run off pollution is substantially less. In municipalities with combined sewer systems, reducing storm runoff is especially important, because excess runoff during heavy storms leads to the discharge of raw sewage from outfalls when treatment plant capacity cannot handle the combined flow. Rain collection systems are simple to install and operate. Running costs are less, and they provide water at the point of consumption.
Rain catchment systems are highly sought after for agriculture use because of the almost neutral PH of rainwater. Rain also has high nitrogen content. Chemicals in municipal water can be very harmful for plants and some ground water can have unbalanced mineral content, because of these factors there is no question that plants love rainwater. The return on investment can be very fast in some agricultural used rain systems do to the amount of water used.
