Rainwater conservation offers a sense of independence from your municipal water service. It is a great back up in areas where summer droughts are frequent. If a home or commercial establishment pay a large amount for water, it provides water supply almost for free.
There are off course some disadvantages of rainwater conservation technologies. These are mainly due to the limited supply and uncertainty of rainfall. The quality of water that you conserve yourself is questionable due to the pollution, dust, insect parts and chemicals found in the roofing. Users must take measures to ensure your water is drinkable, such as filtering it and adding chemicals. Appropriate roofing must also be used.
Municipalities, however, regularly test the quality of their water to ensure purity. Some households might require more water than what they can collect. Your water might be utilized and it can be difficult to switch your water supply back to the municipal source.