Release number

Posted date

2026/5/28

Category

• CSR

Promoting "Water Positive" through Green Infrastructure, including Rain Gardens, to Enhance Sustainable　Water Cycle
Establishment of the Kumamoto Water Positive Design Center

Kumamoto Prefectural University (Chancellor: Tadahiro Kuroda), Kumamoto University (President: Hisao Ogawa), Higo Bank, Ltd. (President: Yoshihisa Kasahara), Suntory Holdings Limited (President & Chief Executive Officer: Nobuhiro Torii), and MS&AD Insurance Group Holdings, Inc. (President & Group CEO: Shinichiro Funabiki) have jointly established the Kumamoto Water Positive Design Center (Kumamoto City, Kumamoto Prefecture, hereinafter "Kumamoto WPDC"). This is in line with the "Kumamoto Water Positive Action" that launched in March 2025, aiming to promote "Water Positive^*1" through the implementation of green infrastructure^*2, such as rain gardens^*3.

*1: Water Positive is defined as offsetting or exceeding the negative impacts of land use change or water intake within a watershed by returning an equivalent or greater amount of water to the watershed through nature conservation, groundwater recharge, use of reclaimed water, etc.

*2: Green infrastructure utilizes the diverse functions of nature to address social issues such as rainwater infiltration, retention, biodiversity conservation, landscape improvement, and climate change, thereby contributing to the creation of sustainable and attractive cities, and regions and enhancing well-being.

*3: A planted area that captures rainwater and allows it to slowly infiltrate into the ground, helping to reduce urban flooding as green infrastructure. Learn more about rain gardens here.

1. Background
Kumamoto prefecture is a region blessed with abundant groundwater resources. However, recent development has led to a decrease in rice paddies and fields, raising concerns over declining groundwater recharge capacity and increasing in flood risk. In response to these challenges, green infrastructure—which replenishes groundwater by promoting the infiltration of rainwater into the ground—is gaining attention. Rain gardens, a type of green infrastructure, can be installed even in developed areas and are expected to provide multiple benefits, including mitigating flood risk, preventing the heat island effect, enhancing landscapes, and promoting biodiversity.
The “Kumamoto Water Positive Action” was launched in March 2025, in collaboration with six organizations from industry, academia and financial institution. Efforts have been made to create a framework in which local governments, companies, and residents of the Kumamoto region can participate in installing rain gardens. In addition, the “Second Kumamoto Regional Comprehensive Groundwater Conservation and Management Plan” announced by Kumamoto Prefecture in March 2026 identified the promotion of rain gardens as one of the key initiative. Thus far, study sessions have been held with local governments, and installation support—including for locations such as Kikuyo Town and Kashima Town—has led to the establishment of three sites.
Kumamoto WPDC has been established to further expand these initiatives and promote Water Positive throughout the region. Going forward, the organization will accelerate activities for a sustainable future for Mizu-no-Kuni Kumamoto (the Land of Water Kumamoto), in collaboration with diverse stakeholders. 

2. About Kumamoto WPDC
Kumamoto WPDC will focus on raising awareness of “Water Positive”, as well as promote the wider adoption of rain gardens through installation support, effectiveness measurement, and standardization. Moreover, it will seek to ensure that these approaches are reflected in local government measures, such as Kumamoto Prefecture’s groundwater recharge guidelines. In addition to government support and preferential treatment from financial institutions, Kumamoto WPDC will develop new funding mechanisms, including the monetization (credit creation) of the groundwater recharge value generated by green infrastructure, which will encourage broader participation by companies and local residents.
The Center will begin recruiting members upon its establishment. Several membership categories will be established—including general members supporting the Center’s mission, declaration members engaging in groundwater recharge, technical members involved in the installation of rain gardens, and co-creative members participating in the Center’s management. In collaboration with local governments, these efforts will accelerate the adoption and social implementation of green infrastructure in the Kumamoto region. 

3. Future Developments
A kickoff event is planned to be held at the “NATURE TECH!” venue during the Nature Positive World Summit 2026^*4, scheduled for July 2026 in Kumamoto City. 

Amid growing threats to society and sustainable business growth from depletion of water resources and deforestation, there is a growing demand in Japan and globally for the creation of sustainable systems where various regional and watershed stakeholders collaborate and mobilize financial resources to protect the value of water and nature. Kumamoto WPDC will share insights gained through its activities and aims to contribute to the global “Nature Positive" and “Water Positive" movements as a leading model originating from Kumamoto.

*4: “Nature Positive” refers to halting and reversing biodiversity loss to put nature on a path to recovery. This summit is an international conference where companies, financial institutions, governments, researchers, and local practitioners from around the world discuss measures to promote the goals of Nature Positive and realize a positive cycle between nature and the economy.

Organization Overview

• 
• Download