Our Approach

Water is an indispensable resource for the SUBARU Group’s business activities. The risk of droughts, floods, and other disasters is increasing, however, due to climate change, while global population growth and economic development are increasing demand for water and raising the risk of water shortages and pollution.
To help alleviate these risks, the SUBARU Group is committed to the proper management of water consumption, as well as to minimizing the environmental impact of its discharged water. We are also actively engaging in activities to conserve forests that have a water storage function.

Water Management

The Production & Environment Subcommittee manages the SUBARU Group’s water usage at each site, and both the total amount and amount used per unit of sales are maintained at a constant level.
The share of each water source in the total freshwater consumption at major locations of the SUBARU Group is as follows: industrial water 50%, tap water 40%, and groundwater 10%. As we are well aware of the risks involved in using the valuable resource of fresh water, we carefully monitor water consumption by conducting water risk assessments at major locations. Although the current assessment results show that the water risk is not high, we will continue to regularly assess our water risk levels and work to reduce water consumption in order to ensure a continuous water supply.

Water Risk Assessment

The SUBARU Group uses a third-party expert to implement water risk assessments* to ensure the sustainable use of water. These assessments estimate, among other things, the water supply and demand risk in the river basins in which the production bases are located, the probability of water-related disasters occurring, and the impact on public health and ecosystems on a five-point scale. These assessments showed that water risk at the Gunma Plant, Utsunomiya Plant, and Subaru of Indiana Automotive, Inc. is generally evaluated as moderate or lower.

Gunma Plant and Subaru of Indiana Automotive, Inc.

According to an assessment in FYE March 2017, the water supply and demand risk at the Gunma Plant and Subaru of Indiana Automotive, Inc., both of which are automobile manufacturing bases, is moderate. It is expected that the current risk level will be maintained for the medium to long term, even when the impact of climate change is taken into account. No biodiversity conservation areas are identified at the lower reaches of the rivers. The vulnerability to water pollution is low.

Utsunomiya Plant

According to an assessment in FYE March 2018, the water supply and demand risk at the Utsunomiya Plant, which is our base for aerospace manufacturing, is moderate. This risk level is expected to drop in the future as an increase in the river flow rate and decrease in water demand are likely to take place. The plant is not located in an area at high risk of flood inundation or landslides. No biodiversity conservation areas or habitats for rare aquatic life are identified in the areas within 10 km downstream from the site. Going forward, we will continue to accurately monitor our water risk based on the assessments, ensure optimum water consumption in relation to local water demand, and help conserve the environment along the river.

* Reference databases
WRI Aqueduct water risk atlas, WWF-DEG Water Risk Filter, PREVIEW Global Risk Data Platform, Climate Change Knowledge Portal, Integrated Biodiversity Assessment Tool, National Land Numerical Information: Possible Inundation Area Data and Sediment Disaster Hazard Area Data (Ministry of Land, Infrastructure, Transport and Tourism), NCD-VfU-GIZ Water Scarcity Valuation Tool (Version 1.0), Costing Nature/Water World, (Only for Gunma Plant and Utsunomiya Plant)

Achievements and Initiatives

Water Consumption

The total amount used is monitored and compiled for each location, and reported and verified at biannual meetings. Necessary measures are then taken as appropriate.

Water Consumption


Gunma Plant, Tokyo Office, Utsunomiya Plant, Handa Plant, Handa West Plant
Group companies in Japan:
Yusoki Kogyo K.K., Fuji Machinery Co., Ltd., Ichitan Co., Ltd., Kiryu Industrial Co., Ltd., Subaru Logistics Co., Ltd.
Overseas Group companies:
Subaru of Indiana Automotive, Inc., Subaru of America, Inc., Subaru Canada, Inc., Subaru Research & Development, Inc.
FYE March 2022 Breakdown of Water Consumption by Water Source at Major Production Bases (1,000 m3)
Region Tap Water Industrial Water Groundwater Source of Water Intake
Japan 217 1,400 235 Tone River, Watarase River
North America 767 0 0 Groundwater from the Teays Valley aquifer
Total 985 1,400 235  


Gunma Plant, Tokyo Office, Utsunomiya Plant, Handa Plant, Handa West Plant, Yusoki Kogyo K.K., Fuji Machinery Co., Ltd., Ichitan Co., Ltd., Kiryu Industrial Co., Ltd.
North America:
Subaru of Indiana Automotive, Inc.

Water Reuse

Utsunomiya Plant

The Utsunomiya Plant has introduced a surface treatment facility equipped with an ion-exchange water recycling system that converts wastewater into pure water. In FYE March 2022, 23,669 m3 (30%) of the total of 78,656 m3 of water used in the surface treatment facility was recycled and utilized at the plant as washing water for the facility.

Representative Surface Treatment Wastewater Processing and Recycling

Subaru of Indiana Automotive, Inc.

Subaru of Indiana Automotive, Inc. added filters to its water tanks equipped with electrodeposition apparatus that are used to clean the car body prior to the painting process. Water is also reused.

Water Discharge

Gunma Plant

The wastewater from the Yajima Plant passes down the Ikoi River and into the Tone River. The water of the Tone River is used to irrigate fields and for fish farming. Households downstream also use the water. We treat wastewater from the Gunma Plant appropriately with the awareness that it touches the lives of many people. In addition, we keep crucian carp and koi carp in the oil-water separation tanks at the Yajima Plant, and release them after confirming that the water quality can sustain fish.

Utsunomiya Plant

In the Utsunomiya area, after treating wastewater from surface treatment processes we discharge it into the sewer system, and discharge rainwater and cooling water into the river after checking its quality in the final water quality monitoring tank. In addition, we dispose of wastewater from the painting process in the Handa area as industrial waste, and treat domestic wastewater in septic tanks prior to discharging it into Kinuura Port and the Agui River.

Utsunomiya Area Wastewater Treatment Process