Japan Rainwater Harvesting Market

Japan Rainwater Harvesting Market Insights Forecasts to 2035

• The Japan Rainwater Harvesting Market Size Was Estimated at USD 100.7 Million in 2024
• The Market Size is Expected to Grow at a CAGR of Around 5.27% from 2025 to 2035
• The Japan Rainwater Harvesting Market Size is Expected to Reach USD 177.2 Million by 2035

According to a research report published by Decision Advisor & Consulting, the Japan rainwater harvesting market size is anticipated to reach USD 177.2 million by 2035, growing at a CAGR of 5.27% from 2025 to 2035. The rainwater harvesting market in Japan is driven by urbanization, limited freshwater supplies, government support for sustainable behavior, and the growing need for water conservation during frequent droughts and climate change.

Market Overview

The rainwater harvesting industry includes a number of systems, technologies, and services for capturing, storing, filtering, and reusing rainwater in residential, commercial, industrial, and agricultural situations. This includes elements including pumps, distribution systems, filtration systems, storage tanks and reservoirs, and catchment systems. The Japan rainwater harvesting market is expanding due to rising concerns over water security, urban flooding, and the need for sustainable water management. Japan's government strongly supports rainwater harvesting when it comes to legislation and expansion of facilities, as well as subsidizing programs. The Ministry of Land, Infrastructure, Transport and Tourism (MLIT) reports that there are over 4,300 public rainwater-use facilities in Japan and that around 12.59 million m³ of rainwater is utilized each year.

The Rainwater Utilization Promotion Law of 2014 calls for rainwater systems to be employed in all new public buildings, while roughly 300 municipalities will offer subsidies for rainwater tanks and system installations to households and commercial businesses, indicating a strong commitment from both national and local entities toward sustainable water management. Technological advancements such as smart monitoring, high-efficiency membrane filtration, and modular rooftop systems are improving adoption. Opportunities are growing in urban redevelopment projects, eco buildings, and industrial water reuse applications.

Report Coverage

This research report categorizes the market for the Japan rainwater harvesting market based on various segments and regions, and forecasts revenue growth and analyzes trends in each submarket. The report analyses the key growth drivers, opportunities, and challenges influencing the Japan rainwater harvesting market. Recent market developments and competitive strategies, such as expansion, product launch, development, partnership, merger, and acquisition, have been included to draw the competitive landscape in the market. The report strategically identifies and profiles the key market players and analyses their core competencies in each sub-segment of the Japan rainwater harvesting market.

Driving Factors

The rainwater harvesting market in Japan is driven by concerns about water security, flooding in urban areas, and the government promotion of sustainable water management. Initiatives focusing on utilizing rainwater in public buildings, disaster-resilient infrastructure by MLIT, and green urban planning encourage more people to adopt rainwater harvesting. Increased environmental awareness, the demand for circular water systems, and pressures to decrease reliance on municipal supplies will also drive growth. Furthermore, technology helps improve and continuously advance filtration development, smart monitoring, and modular storage, which leads to more efficient rainwater harvesting throughout urban and rural locations.

Restraining Factors

The rainwater harvesting market in Japan is mostly constrained by high installation and maintenance costs, limited space to install storage tanks in urban high rises, and differences in local municipal regulations. The public awareness of rainwater harvesting is still an issue, and retrofitting existing older buildings to utilize rainwater harvesting often entails significant costs for structural modifications.

Market Segmentation

The Japan rainwater harvesting market share is classified into harvesting method and end user.

• The above ground segment accounted for the largest revenue market share in 2024 and is expected to grow at a significant CAGR during the forecast period. 

The Japan rainwater harvesting market is segmented by harvesting method into above ground, and under ground. Among these, the above ground segment accounted for the largest revenue market share in 2024 and is expected to grow at a significant CAGR during the forecast period. This is due to the fact that above ground solutions, like barrel-type installations, rooftop tanks, and modular storage units, are more affordable, simpler to construct, and frequently supported by municipal subsidy schemes.

• The commercial segment accounted for the largest revenue share in 2024 and is expected to grow at a significant CAGR during the forecast period. 

The Japan rainwater harvesting market is segmented by end user into commercial, residential, and industrial. Among these, the commercial segment accounted for the largest revenue share in 2024 and is expected to grow at a significant CAGR during the forecast period. This is due to national regulations that aggressively encourage or mandate the adoption of rainwater systems for non-potable applications like toilet flushing, irrigation, and disaster preparedness in commercial facilities, including public buildings, schools, workplaces, hospitals, and retail centers.

Competitive Analysis:

The report offers the appropriate analysis of the key organizations/companies involved within the Japan rainwater harvesting market, along with a comparative evaluation primarily based on their product offering, business overviews, geographic presence, enterprise strategies, segment market share, and SWOT analysis. The report also provides an elaborate analysis focusing on the current news and developments of the companies, which includes product development, innovations, joint ventures, partnerships, mergers & acquisitions, strategic alliances, and others. This allows for the evaluation of the overall competition within the market.

List of Key Companies

• Sekisui Chemical
• Alco Co., Ltd.
• ES Waternet
• Tozai Shoji
• Seawater Chemical Industry
• Meidensha Corporation
• Ebara Corporation
• Ichigo Inc.
• Nissei K?san
• Eco Factory
• Others

Key Target Audience

• Market Players
• Investors
• End-users
• Government Authorities 
• Consulting and Research Firm
• Venture capitalists
• Value-Added Resellers (VARs)

Recent Developments:

• In August 2025, the Rainwater Storage & Infiltration Technology Association announced its “Rainwater Utilization Facility Maintenance Technician” exam.
• In February 2025, as part of international cooperation, a JICA seminar in Hanoi showcased Japanese underground plastic rainwater tanks for flood mitigation.

Market Segment

This study forecasts revenue at the Japan, regional, and country levels from 2020 to 2035. Decision Advisor has segmented the Japan rainwater harvesting market based on the below-mentioned segments:

Japan Rainwater Harvesting Market, By Harvesting Method

• Above Ground
• Under Ground

Japan Rainwater Harvesting Market, By End User

• Commercial
• Residential
• Industrial

FAQ’s

Q: What is the Japan rainwater harvesting market size?

A: Japan rainwater harvesting market size is expected to grow from USD 100.7 million in 2024 to USD 177.2 million by 2035, growing at a CAGR of 5.27% during the forecast period 2025-2035. 

Q: What are the key growth drivers of the market?

A: Market growth is driven by concerns about water security, flooding in urban areas, and the government promotion of sustainable water management. Initiatives focusing on utilizing rainwater in public buildings, disaster-resilient infrastructure by MLIT, and green urban planning encourage more people to adopt rainwater harvesting. Increased environmental awareness, the demand for circular water systems, and pressures to decrease reliance on municipal supplies will also drive growth.

Q: What factors restrain the Japan rainwater harvesting market?

A: Constraints include high installation and maintenance costs, limited space to install storage tanks in urban high rises, and differences in local municipal regulations. The public awareness of rainwater harvesting is still an issue, and retrofitting existing older buildings to utilize rainwater harvesting often entails significant costs for structural modifications.

Q: How is the market segmented by end user?

A: The market is segmented into commercial, residential, and industrial.

Q: Who are the key players in the Japan rainwater harvesting market?

A: Key companies include Sekisui Chemical, Alco Co., Ltd., ES Waternet, Tozai Shoji, Seawater Chemical Industry, Meidensha Corporation, Ebara Corporation, Ichigo Inc., Nissei K?san, and Eco Factory.

Q: Who are the target audiences for this market report?

A: The report targets market players, investors, end-users, government authorities, consulting and research firms, venture capitalists, and value-added resellers (VARs).