In Taiwan, drones get credit for reducing illegal hillside developments

Taichung, a city in central Taiwan, says satellites, drones and inspectors on foot are helping it catch illegal development on its hillsides. Hillside violation cases that its Water Resource Bureau (台中市政府水利局) reported and acted on fell from 163 in 2024 to 106 in 2025, the bureau said, according to the Central News Agency (中央社). It counted 80 in the first nine months of 2026. The bureau says the decline shows its technology monitoring and enforcement are working.

Across Taiwan, illegal hillside developments typically include farming, road building, dumping, and quarrying. Unapproved gravesites, fishponds, and solar facilities have also been cited.

In the bureau's method, set out in its release, satellite images are compared regularly to flag suspected illegal development, then drone photos and staff on site check how the land is actually used. Hillside land covers a wide area, and "traditional patrols find it hard to keep full track of how the land is used," the release said.

The satellite step isn't Taichung's alone. Taiwan's national Agency of Rural Development and Soil and Water Conservation (農村發展及水土保持署) used remote sensing to detect 6,977 "change points," spots where images from above show the land has changed, in the first 11 months of 2025. It sent all of them to local governments to check, the agency wrote in a government journal article.

Neither the Oct. 26 release nor the bureau's March 2026 report to the city council says when they started flying, how many there are or who flies them. That report put the city's hillside land at more than 150,000 hectares (more than 370,000 acres), about 70% of its area. It said 10 full-time patrol inspectors handle hillside patrols and violation reporting, and it did not mention drones.

Sources: 中央社 Central News Agency, 台中市政府 Taichung City Government (Water Resource Bureau release), 臺中市政府水利局 Water Resource Bureau of Taichung City Government (council work report), 農村發展及水土保持署 Agency of Rural Development and Soil and Water Conservation

Editor: Ian Lamont