Midori-chan – vegetation planting system minimizes water usage

After writing about green roofs and green walls implemented in various architectures, we are going to write an article of a system that eases the maintenance of green roof foliage. Midori-chan is a system designed to maximize vegetation growth and recycle waste, while dramatically minimizing water usage. The engineers at the Kawada Group in Japan developed the system to meet the demands of greener and cleaner communities.

As a part of the Kawada Group commitment to corporate social responsibility, Midori-chan was conceived in the late 1990s in order to recycle building materials and ease the heat island effect.  Midori means “green” in the Japanese language. The word “chan” after “midori” is a diminutive suffix which expresses that the speaker finds a person endearing, and it’s commonly used for children.

Midori-chan is based upon a system in which rainwater is effectively recycled, stored, and supplied to vegetation. The system mimics and improves upon the system of water supply and evaporation that occurs naturally in the earth’s surface. Special water retention materials grip water vapor. Soil moisture transfer is generated by thermal energy balance in the soil and facilitated by water storage units. Regenerated charcoal cleanses the water through natural water vapor absorbed through the plant roots.

Midori-chan is a concept utilizing the principles of 3R + 1. Reduce, Recycle, Reuse + Respect. When it was applied in Japan it reduces water usage by using 90% less water compared to other systems. It enables usage of grey-water since it filters it through the charcoal, leaving the watering with fresh water as an option. The materials used for the water storage unit and the water-retention materials are made from previously recycled building materials. The last, Respect, was used to emphasize the natural way Midori-chan system is designed to work like the earth and to respect the earth, since its process occurs naturally.

Midori-chan system reduces CO2 and increases vegetation without draining already limited world water resources. The green roofs lessen the rooftop temperature from 62°C (143.6°F) by stunning 30°C (86°F). The lowered building temperature lessens the need for air conditioning, and consequently it reduces the power consumption and CO2 emission. Their system is also applicable on green walls and on other surfaces where there is no direct access to the soil (as bridges or planters).