The new Sushi – Japanese Rainwater Harvesting policy

Like many of you, I have cheerfully embraced sushi, sashimi, Asahi, zen landscapes and minimalist interior design from the land of the rising sun. So when a colleague recently sent me an article on the 2014 Rainwater Act to Advance the Utilization of Rainwater in Japan, aiming for a 100% installation rate of rainwater harvesting in all new government buildings in Japan, I looked at it with interest.

The Minister of Land, Infrastructure, Transport and Tourism also prescribed the Basic Principles to Advance the Utilization of Rainwater. This includes the significance of promoting rainwater utilization and technical points to be observed, methods for water management to prevent adverse effects on human health, and the roles of the state and local governments in achieving these principles.

It turns out that the Japanese are quite keen on rainwater harvesting. They have some intriguing ideas like a Rainwater Museum in the Sumida ward and community and business groups for the advancement of rainwater harvesting. An increasing number of organizations and municipalities have been turning to rainwater utilization in the last decade. Their aims include finding alternative water sources for drinking water, preventing urban flooding and securing emergency water sources for disaster-responses.

When Kobe City was devastated by earthquake in 1995 the water supply, from a lake 150km away, was cut off for a month. A group called ‘People for Rainwater’ distributed 100, 200 litre rainwater harvesting tanks daily across the city to provide emergency water for drinking, cooking and washing. The principle is an important one, central infrastructure linear systems are more vulnerable to disruptive change. Collection and distribution at points throughout the network, like rainwater harvesting, can be cheap and effective. Additionally if you have a linear design increasing the capacity requires the whole system to be upgraded, point form collection and distribution like rainwater harvesting is much easier to upgrade only where it is needed. If you are interested in these concepts see the work of Peter Coombes at Urban Water Cycle Solutions.

Australia enjoys a very high take up of rainwater harvesting, 26% of Australian households in this thirsty country have a rainwater tank. Do we need a national policy prioritising rainwater harvesting or is it going along pretty well already?

Source Article:

This image file was provided to Wikimedia Commons by Rijksmuseum as part of a cooperation project with Europeana, using the GLAMWiki Toolset.