The irrigation management area under the jurisdiction of the Office includes nine townships: Tamsui, Sanzhi, Shimen, Jinshan, Wanli, Ruifang, Pingxi, Shuangxi, and Gongliao in New Taipei City and Keelung City, with a total area of 821km². The area is bordered by mountains and coastal areas, with overlapping mountains, a few plains, rapidly flowing short rivers, and few water sources. Irrigation canals are carved along the mountains and valleys, with as many as 330 canals throughout the area, plus more than 1,190 small ditches crisscrossing the fields, with an irrigated area of 5,138 hectares, canals scattered on both sides of mountain streams and valleys with terraced fields. The area is vast, and travel conducted mainly on foot. Transportation is extremely inconvenient, and management very difficult.

The office has jurisdiction over up to 330 diverting irrigation canals and 1,190 small ditches, mainly diverting water from Guizikeng River, Waiganzhenlin River, Zhuangzinei River, Xiaguiroushan River, Xinghuadian River, Gongsitian River, Houzhouzi River, Huiyaozi River, Datun River, Balian River, Dakeng River, Bajia River, Fenglin River, Laomei River, Shimen River, Alibang River, Huang River, Qingshui River, Daozhaohu River, Shichuizi River, Jinbaoli River, Yuantanzi River, Lujueping River, Keelung River, Dahu River, Shuangxi River, Yuanwangkeng River, Fangjiao River, Shibikeng River, Dingzilankeng River, Pinglin River, Mudankeng River, Longlong River and Shiding River. In addition, some spring water and pond water from various locations is diverted for irrigation purposes, and there are eight deep underground wells dug outside ponds distributed throughout the area to provide supplementary irrigation.

The irrigation canals in this area crisscross deep hollows and valleys, winding along the mountainside and at the edge of streams. The construction conditions are particularly harsh. Most of the irrigation waterways within the jurisdiction were originally located in mountainous areas, with undulating terrain and extremely variable stream and river flow. In addition, farmers are increasingly concerned about their own rights and interests. As such, the construction of farmland irrigation projects involves much more than technical or quality issues and the demands involved are much greater than in the past. Many irrigation canals in this area are equipped with canal headworks to block water for irrigation. The construction of barrage weirs needs to take into consideration the volume of upstream and downstream water allocated and water gates and other water control and water distribution facilities must be installed in each canal. However, the great variability of river flow from abundance to drought, means that continuous and extensive efforts and funding are required to ensure the facilities operate as expected when it comes to diverting water for irrigation and appropriately allocating water volume.

The area under the jurisdiction is mountainous, and many of the irrigation areas are in hillside conservation areas. The natural conditions and environment are poor, resulting in frequent disasters. Funds are invested every year to improve farmland irrigation facilities and handle natural disaster emergency repairs delivering good results.