Countless taps of safe drinking water in the Sky!
Sky water is the blessing from heaven:
Sky water is free from heavy metal, such as arsenic and iron, salinity and germs originating from human feces. Sky water is the on-site drinking water resource which make fetching water free.
Sky water is the final clean drinking water resource for next generation:
Still now, sky water is the most total dissolved solids in the drinking water resources, such as ground water, river water and sea water. Sky water is the product of the natural desalination systems which have been made by global water circulation caused by solar energy (Photo2: Sky water is less contamination more than other drinking water resources). Heavy discharging wastewater into the river, the pond and the lake has made caused severe water pollution of drinking water resources. Rapidly increasing global population and human active activity has accelerated drinking water pollution all around the world. Bangladesh is no exception. Sky water is becoming final clean drinking water resource for humankinds.
Sky water harvesting is the key solution for drinking water crisis in Bangladesh:
As a solution to solve the above severe drinking water crisis, highly advanced technology, such as reverse osmosis, is available. It can remove arsenic, iron, salinity, and germs, but its installation, operation & maintenance is too expensive for local people in Bangladesh. Another solution is to purchase bottled water, but it is possible for only rich people to buy it every day. In the other hand, sky water is free and available for all. A sky water harvesting system can be installed in a short time. And its Operation & Maintenance (O & M) is simple. Annual average rainfall in Bangladesh is more than 2000 mm. Sky water harvesting is the key solution for drinking water crisis in Bangladesh.
History of sky water harvesting in Bangladesh:
Before drinking water artificially purified by modern water supply systems in Japan which started 128 years ago, people drank “natural water”, such as, river water, lake water, spring water, ground water and rainwater. Rainwater has been the main source of drinking water in isolated islands in Japan. Bangladesh has the same history. Local people in rural areas collected rainwater to drink in the earthenware pot called “Motka”. Still now they harvest rain into a Motka and use it for drinking and cooking in the rainy seasons. They have recognized sky water is safer than pond water, that’s why they have reserved sky water for their friends and relatives. After 10 minutes, when rainfall with high intensity flushed out dust and leaves on the roof, they have used to harvest clean rain through galvanized gutter into a Motka with its mouth covered with cloth. The cloth filters the water and prevents invasion from mosquitos. They have learned how to harvest safe rain through experiences over time. But Motka has weak points. Motka, which is affordable for poor people, has a capacity of 50-100 liters. But it is too small to cover drinking water needs over the dry season and also is fragile（Fig 4 Motka）.
Innovation of sky water harvesting system for all:
To break through this issue, SBL developed a new low-cost tank which is solid, and has a larger capacity than Motka by modification of the technology of Thai giant jar which is made from mortar. It was named AMAMIZU. AMAMIZU is made from mortar reinforced steel wire net. The capacity of AMAMIZU is 1000L.
“AMAMIZU” is Japanese word which has a meaning of “sky water”. We wanted to call “rainwater” as “sky water” through learning the wisdom of our ancestors. Sky water is a gift from heaven. Our ancestors have harvested rain and used it for drinking water, and they called rainwater “sky water” with great respect. AMAMIZU has one more meaning. It means sweet water. AMAMIZU has climate change adaptation which is causing salinity issue of drinking water resources.