Rainwater is a significant water resource in Thailand due to its abundance. It has been
widely used in sectors of the society especially in households and in agriculture. Being
dominated by monsoons, rainwater can be harvested mainly in the rainy season which in
most parts of Thailand generally starts in June and lasts until October with an average
rainfall per annum at 1,500-1,600 mm [1]. Rainwater utilization has been in use for more
than 2,000 years in the Thailand [2]. In the past cement and earthen jars have been used as
containers for collecting and storing rainwater in Ayutthaya. There is an impending water
crisis given the high growth in water demand, the corresponding shortage of water
supply, and a possible increase in water tariffs in part due to the need to expand water
supplies. This can be offset because of the existence of sufficient levels of rainfall and the
availability of the option of rainwater harvesting. Undertaking a pilot project in a
province like Ayutthaya which reflects the situation in central part of Thailand to
promote rainwater harvesting is an effective way to demonstrate how combining current
technologies with existing resources and materials in a cost-effective manner can resolve
the water crisis in the years to come.
Given the progress of the country's development, access to basic infrastructure has
increased considerably particularly in piped water supply systems serving domestic
sectors. In 2002, 95% of Thailand's urban populace had access to some form of water