Kumamoto's Ground Water: Suntory's Nature Sanctuary Success

Kumamoto, Japan, uniquely sources its tap water for nearly one million residents almost entirely from groundwater. This phenomenon is attributed to the porous volcanic soil, a result of ancient Mount Aso eruptions, which naturally filters rainwater deep underground and enriches it with minerals.

Recognizing this valuable resource, Suntory Holdings established its Kyushu Kumamoto Plant in 2003. The facility utilizes this high-quality groundwater for producing beverages such as beer and its signature Suntory Tennensui natural mineral water. This commitment extends to environmental stewardship.

In the same year, Suntory launched its first Natural Water Sanctuary in Kumamoto. This initiative focuses on enhancing water-source recharge capabilities and preserving biodiversity through expert collaboration. Activities include forest research, action plan formulation, and hands-on conservation efforts like trail maintenance and planting.

The Natural Water Sanctuary program, now active in 27 locations across 16 prefectures, covers over 12,000 hectares. It aims to restore resilient forest ecosystems that promote soil health and water infiltration, contributing to disaster prevention and sustaining local water resources for businesses and communities alike.

Distinctive local projects include the 'fuyumizu tambo' (winter-flooded rice paddy) initiative, which continuously floods paddies during winter to promote groundwater infiltration outside forested areas. Efforts also focus on converting abandoned farmland into wetlands to create habitats and support biodiversity, alongside exploring organic farming practices.

To combat urban flooding caused by development, the 'Kumamoto Water Positive Action' initiative was launched in March 2025. This project, involving academia, industry, and finance, promotes green infrastructure like rain gardens for broader groundwater recharge participation.

Suntory's efforts are globally recognized; the company holds the highest Platinum certification from the Alliance for Water Stewardship (AWS) and co-founded the Japan Water Stewardship Leadership Group in 2025. These actions underscore a commitment to collaborative watershed management beyond individual company sites.