Introduction to Gokase River
Gokase River is a class-one river having the length of 106 km and the catchment area of 1,820 km2, and running through two cities and five towns. Gokase River rises in Mt. Mukousaka located between Miyazaki and Kumamoto Prefectures, passes through the steep Kyushu central mountains and the Nobeoka plains, and pours into the Pacific Ocean. Where the river runs on the volcanic ash soil of Mt. Aso near RG, the river flow has created many small ravines which provide a high river density.
On the Nobeoka plains, the river forks into two rivers which are Gokase River and its branch, Ose River, which meet again near the river mouth where Houri River and Kita River also flow into them. Houri River rises in one of the well-known mountains in Kyushu District, Mt. Daihou, and Kita River rises in Mt. Katamuki in Ume Town in Oita Prefecture. Each of these rivers has a long span over mountainous areas and, therefore, their many branch rivers have rich nature still remaining. Therefore, both of the two rivers enjoy their excellent environment where many river banks with gravel on them still remain.
The Gokase River region enjoys its annual precipitation of about 2,400 mm. The river’s abundant water has long been used for the rich industries and culture around it. This region often suffers flood damage caused by typhoons. Therefore, around the river, there are some remains of constructions related to the excellent “river culture” which protects the local community from floods, such as “Kasumi Zutusmi (Haze Embankment)” remaining around Kita River and “Tatami Zutsumi (Japanese-Mat Embankment)” still remaining in the Nobeoka City, which manages the increase of the water level for the time being by inserting Japanese mats into the parapet on the embankment.
Nobeoka City used to be called “Capital of Water”. Therefore, “Ayu-Yana (sweet fish trap)” is set up even today in the city every year and Ayu fishing is actively carried out in rivers all over the city. The mountains surrounding Gokase River used to produce fuel wood and, therefore, craft flowing and shipping used to be prosperous in this region for transporting the fuel wood. Nowadays, we mainly see boats used to Ayu fishing in the river. However, an event called “River Festa” aiming at having the children get familiar with rivers, has become flourishing.
Gokase River is just about to create a new link by connecting its basin.