This Association is situated from the south of Tatun mountain to Tanshui river, Keelung river and Wuchih mountain range system, and to Keelung river in the east. It belongs to the north and north-east of Taipei basin, and its slope lowers down from the north to the south, and from the west to the east. The mountains in the north are volcanos, and the west is the world arranged with row. Its plain belongs to Taipei lake after flood, and the whole terrain of this territory is very different over 800 meters. The rivers are collected to the center of basin, and there are many valleys between mountains. The annual rainfall is about 1,800-3,000 mm, and the average temperature is about 20-30℃. Basing on the limitation of natural environment, the water resources are scattered, by the water quantity is sufficient to be equipped with fan-type canal.
In the process of development, there were more than 72 canals built here to intake water from Keelung river, Huang stream, Shuang stream, Kuitzekeng and Shuimokeng stream, so the length of each canal is about 200 meters to 7,000 meters. Most of the irrigation canals are short and torrential to be scattered everywhere, and also there were 7 canals scattering over Chihsin mountain area at elevation of 300 meters to 700 meters. However, for the progress of Taipei city, there are only 26 irrigation canals lefy in Taipei city.