Environmental Impact Assessment Act amendment to be enforced April 1, 2027

In the extraordinary issue of the Official Gazette dated October 15, 2026, the Government promulgated Cabinet Order No. 326, which establishes April 1, 2027, as the enforcement date for the Act for Partial Amendment of the Environmental Impact Assessment Act (Act No. 73 of 2025). This order was enacted by the Cabinet based on the main text of Article 1 of the Supplementary Provisions of said Act and is signed by Prime Minister Sanae Takaichi and Minister of the Environment Hiroyoshi Sasagawa. On the same date, Cabinet Order No. 327 (Cabinet Order for Partial Amendment of the Order for Enforcement of the Environmental Impact Assessment Act), which organizes the substantive provisions of the enforcement order, was also promulgated.

The Environmental Impact Assessment Act subject to amendment is Act No. 81 of 1997, and the current amended Act is structured to provide a preparation period between promulgation and enforcement. Cabinet Order No. 327 amends the Order for Enforcement of the Environmental Impact Assessment Act (Cabinet Order No. 346 of 1997) and was enacted based on the portions of Article 2, Paragraph 2 of the Act other than the listed items, Item 2(a) of the same paragraph, Paragraph 3 of the same article, and Article 3-3, Paragraph 2 of the Act; it shall come into effect from the enforcement date of the amended Act (April 1, 2027) pursuant to the Supplementary Provisions.

Enforcement Date Fixed for April 1, 2027

Cabinet Order No. 326 is a short order consisting of a single sentence, stipulating that the enforcement date of the amended Act shall be April 1, 2027. Enforcement will occur approximately one and a half years after promulgation, ensuring a period for business operators and administrative agencies to prepare procedures.

• Name of Law/Regulation: Cabinet Order Establishing the Enforcement Date of the Act for Partial Amendment of the Environmental Impact Assessment Act
• Cabinet Order Number: Cabinet Order No. 326
• Promulgation Date: October 15, 2026 (Extraordinary Official Gazette)
• Legal Basis: Main text of Article 1 of the Supplementary Provisions of the Act for Partial Amendment of the Environmental Impact Assessment Act (Act No. 73 of 2025)
• Enforcement Date: April 1, 2027
• Signatories: Prime Minister Sanae Takaichi, Minister of the Environment Hiroyoshi Sasagawa

Amendment of Enforcement Order to Subdivide Scale Categories for Dams and Discharge Channels

Cabinet Order No. 327 revises the appended table of the enforcement order to establish new scale categories for large-scale dams and discharge channels. The portion previously treated collectively as 100 hectares or more will be split, positioning projects of 75 hectares or more but less than 100 hectares as Class 2 projects.

• Appended Table 1, Item 2: New construction of dams with a reservoir area of 100 hectares or more is classified as “Large-scale Dam New Construction,” and new construction of dams with a reservoir area of 75 hectares or more but less than 100 hectares is classified as “Type II Dam New Construction Project.”
• Appended Table 1, Item 5: “New construction of dams” is changed to “Dams,” and “Large-scale dam new construction or” is changed to “Large-scale dam new construction or large-scale dam reconstruction or,” adding dam reconstruction to the scope.
• Appended Table 3, Item 4: In addition to the new construction of discharge channels that change the shape of land of 100 hectares or more, the new construction of discharge channels of 75 hectares or more but less than 100 hectares is added.
• Appended Table 2 and Appended Table 3: The numbers of the project classifications are shifted down (changing “Ho” to “Nu,” “He to Yo” to “Ru to Ne,” “Ta” to “Na,” and “Re” to “Ra”).

Establishment of New Values for Distance from Existing Structures and Output

Cabinet Order No. 327 adds Article 7-2 after Article 7 of the Enforcement Order, specifying the “distance from the boundary of the area where existing structures are installed” and the corresponding values for each project classification, as delegated to the Cabinet Order by Article 3-3, Paragraph 2 of the Act. Additionally, it clearly specifies the output requirements for hydroelectric power plants and organizes the handling of projects carried out by river administrators.

• Projects falling under Ho or He of Item 5 of Appended Table 1: Distance of 300 meters, value for power plant or power generation equipment output is 2.0.
• Projects falling under To or Chi of Item 5 of Appended Table 1: Distance of 300 meters, value for power plant or power generation equipment output is 1.3.
• Cases where the output of a hydroelectric power plant is 22,500 kilowatts or more are clearly specified as requirements for Type I and Type II dam new construction projects.
• Projects carried out as river works by the Minister of Land, Infrastructure, Transport and Tourism, prefectural governors, mayors of designated cities, and the Japan Water Agency (Independent Administrative Institution) are classified.

Due to this Cabinet Order, from April 1, 2027, the environmental impact assessment procedures for large-scale development projects such as dams, hydroelectric power plants, and discharge channels will be determined based on new classifications according to reservoir area, output, and distance from existing structures. Since the new construction of dams and discharge channels of 75 hectares or more but less than 100 hectares is newly positioned as Type II projects, and dam reconstruction is also added to the scope, river administrators and power generation operators will be forced to review the timing and scope of the procedures for draft environmental impact statements and final environmental impact statements.

Sources

• Official Gazette, October 15, 2026 (Thursday) Extra Edition, Cabinet Order No. 326 “Cabinet Order Establishing the Enforcement Date of the Act for Partial Revision of the Environmental Impact Assessment Act”
• Official Gazette, October 15, 2026 (Thursday) Extra Edition, Cabinet Order No. 327 “Cabinet Order for Partial Revision of the Order for Enforcement of the Environmental Impact Assessment Act”