Tanks can be installed either above or below ground. Tank location is dependent on aesthetics, climate and soil conditions. Some prefer not to see the storage tank and opt to bury it. However, placing tanks underground adds to installation costs and may be limited in areas where soil is especially rocky. When tanks are installed below ground, water is maintained at a cool temperature and light is blocked, thereby reducing chances of bacterial growth. Some tanks are not suitable for certain climatic areas. Wood tanks are not recommended for hot, dry locations. However, installing tanks below ground may not be advisable in the mountainous regions and areas with a high groundwater level.
Rainwater harvesting system has been implemented in many countries such as USA, Japan, China, India, Germany and Australia to support the increasing water demand. The integration between rainwater harvesting system and existing conventional water supply systems will help to meet the demand and contribute in the sustainability of the water supply.
Rainwater can be captured by using the rainwater harvesting system. Generally, rainwater harvesting system is the direct collection of rainwater from roofs and other purpose built catchments, the collection of sheet runoff from man-made ground or natural surface catchments and rock catchments for domestic, industry, agriculture and environment use. The systems can be categorized as small, medium and large scale. Normally, the size of rainwater harvesting was based on the size of catchment area. In scientific terms, rainwater harvesting refers to collection and storage of rainwater and also other activities aimed at harvesting surface and groundwater, prevention of losses through evaporation and seepage and all other hydrological studies and engineering interventions aimed at conservation and efficient utilization of the limited water endowment of physiographic unit as a watershed.