The office is located in the central and southern part of the west coast of Taiwan, from Chenyoulan River in Nantou County to the east along the west foothills of the Central Mountain Range, adjacent to the Taiwan Strait in the west, Zhuoshui River in the north, and Sandie River in Chiayi County in the south. It is about 40 kilometers from north to south and about 80 kilometers from east to west. Average annual rainfall in the irrigation area is about 1,500 mm. Rainfall is abundant but distribution over time and space is extremely uneven. The rainy season is from May to October, accounting for about 80% of annual rainfall, with rainfall from November to April being roughly 20%. Because the sand content of the water source is as high as 0.4% in this irrigation area, it can cause channel silting making irrigation facilities difficult to maintain and manage.
- Irrigation water sources: there is no reservoir in the irrigation area and the water supply is extremely unstable. The completion of Jiji River Weir in 2000 stabilized the water intake from the Zhuoshui River area so it can also play a role in regulating irrigation. Irrigation water sources used by the office are: (1) Surface water: from the natural water flow of Zhuoshui River, Qingshui River, Beigang River and Huwei River. (2) Groundwater: Groundwater resources have been developed with 582 deep and shallow wells drilled and electric water pumps used. (3) Supplementary water sources: The drainage system in the area and the pits, ponds and water surge areas are used to extract recycled water, with 71 pumping stations.
- Irrigation channels: There are 10,949 irrigation channels including Zhuo Main Canal, Douliu Canal, Xinhuwei River Sub-lateral Canal, Luchangke Canal, Longen Canal, and Jiji large, small, main, lateral and sub-lateral canals, with a total extension length of 7,337,246 meters.
- Drainage channels: there are 12,419 drainage facilities, with 114 large drainage facilities, 766 medium drainage facilities and 11,539 small drainage facilities, with a total extension length of 6,614,517 meters. The outlets of the drainage channels directly enter the Zhuoshui River, Beigang River and Taiwan Strait.
- Irrigation scheme: The main irrigation water sources in the area under the jurisdiction of the office are from Zhuoshui River and Qingshui River, which is river-flow type irrigation. Due to the extremely unstable water supply, supplementary water sources also need to be developed, including extracting recycled water, digging deep and shallow wells, and pumping groundwater to make up for limited irrigation water. However, due to the characteristics of the river water sources, the volume of water is still insufficient for irrigation purposes. Therefore, most of the fields within the jurisdiction adopt crop rotation cultivation.
- The cultivating fields include double cropped fields, single cropped fields, single cropped in two years fields, and single cropped in three years fields.