There are many reasons why homeowners prefer rainwater harvesting to supplement municipal water supply or borehole water. For starters, some parts of Australia experience prolonged droughts, which cause water shortages. Also, some homeowners require a constant supply of water for domestic and agricultural use year-round. In this regard, rainwater harvesting can bridge the gap by providing water for washing, cleaning and watering animals and irrigation. Central to a rainwater harvesting system is a rainwater tank.