#Japan #Tokyo #Green Infrastructure #Cainz #Rainwater Management

Cainz Collaborates with Tokyo Urban Development Bureau for Green Rainwater Management Initiative

Cainz, a leading home improvement chain in Japan, officially signed an agreement with the Tokyo Urban Development Bureau on September 1, 2025, to create model facilities aimed at reducing rainwater runoff. This collaboration sees the establishment of rain gardens at two Cainz locations in Tokyo—Ome Interstore and Akishima Store—where rainwater storage and infiltration systems have been integrated.

In recent years, Tokyo faces increasing challenges related to flooding caused by intense rainfall. In response, the Tokyo government has been promoting the use of green infrastructure as part of its Basic Policy for Rainstorm Measures to mitigate the negative impacts of heavy rain. Rain gardens are recognized as a crucial solution, enhancing urban disaster resilience while also reducing environmental footprints.

As part of this initiative, Cainz was selected to support a green infrastructure project launched by the Tokyo Urban Development Bureau, allowing the home improvement retailer to construct model facilities on its premises. Rain gardens serve multiple purposes—they temporarily store rainwater collected from roofs and pavements, slowly allowing it to seep into the ground. This not only helps alleviate urban flooding but also enhances soil moisture retention, supporting healthy plant growth and promoting biodiversity by providing habitats for various insects and small animals. Additionally, as rainwater filters through the ground, it contributes to water purification, thus aiding in reducing urban environmental loads.

The Concept of Rain Gardens

A rain garden is essentially a landscaped area that collects and absorbs rainwater runoff from impervious surfaces like roofs and driveways. By channeling stormwater into these gardens, cities can effectively curb flooding risks while simultaneously fostering environmental sustainability. The establishment of rain gardens showcases the potential of urban landscapes to function as eco-friendly infrastructure, fulfilling multiple roles from aesthetics to biodiversity enhancement.

Model Facilities and Community Education

In December 2025, rain garden model facilities were installed at Cainz’s Ome Interstore and Akishima Store. These demonstrations allow customers to experience rain gardens firsthand, gaining insights into their benefits and the importance of rainwater management. The aim is not only to educate but also to encourage homeowners to implement similar green solutions in their own spaces.

Moving forward, Cainz will collaborate with the Tokyo government to evaluate the effectiveness of these initiatives, contributing to the overall enhancement of urban resilience and environmental value. The company also offers various supplies necessary for rain garden setup—such as rainwater tanks, gravel, and plants—reinforcing the initiative's outreach and support.

This marks Cainz's first venture into rain garden installations, supported by training from the Setagaya Trust Urban Development and research contributions from Hiroshi Kamiya, a visiting researcher at Hosei University Eco-Region Design Center. Through these partnerships, Cainz aims to expand awareness and accessibility of rain gardens across more locations, enabling everyone to incorporate such environmental solutions into their homes.

Community Engagement and the Kumimachi Concept

Under the vision of “DIY for the community,” Cainz has long held the ethos of contributing to societal progress through commercial endeavors. Each store operates as a community hub, actively listening to local needs and preferences, thereby fostering a cooperative environment among various stakeholders in the community. This initiative is part of Cainz’s broader Kumimachi project (kumimachi.com), which aspires to create vibrant, self-sufficient communities where every individual is empowered to contribute.

About Cainz

Founded in March 1989, Cainz has grown into a home center chain with 262 stores across 29 prefectures in Japan. With a brand concept focusing on life DIY, Cainz strives to enrich lives by providing valuable products and services daily at reasonable prices. The company emphasizes kindness and innovation in its retail approach, ensuring that shopping at Cainz enhances the daily lives of customers and aligns with its promise: “Enriching life, every day.”

For more information, check the official Cainz website at Caiz Official Site.