Officials in Hokkaido, northern Japan, have called for a halt to the construction of a major solar-power generation project near the country’s biggest wetland.

Prefectural officials notified the Osaka-based developer on Tuesday. They cited its failure to obtain approval from the governor of Hokkaido before starting the work.

The firm is planning to install 6,600 solar panels in wooded areas near the Kushiro Marsh national park.

Companies building a solar-power facility in a privately managed forest are legally required to notify the local governor if the affected land exceeds 0.5 hectares.

The operator says it believed the area of the site was smaller than that and went ahead with construction. But when officials inspected the site in August, they found it extended to more than 0.8 hectares.

The Forestry Agency tightened legal requirements on development three years ago, amid a growing number of solar-power projects in woodlands across Japan.

Environmental conservation groups have raised concerns about the project being located so near the Kushiro wetland. They say it would affect the habitats of rare red-crowned cranes and white-tailed eagles, both of which are endangered species.

AloJapan.com