3: What is the plan like? 3-2-1

Niseko Town has many tourist accommodation facilities, and the amount of water supply per population served is higher than the average for all roads. However, the diffusion rate of water supply is 83.3% (2000) and 96.1% for all roads (1998). It remains at a lower level.
Niseko Town has 12 water sources, most of which are spring water (8) or groundwater (3), with only one source of surface water. Niseko Town spring water or groundwater is water quality that does not require any artificial treatment, but it is only sterilized by the water supply method to provide delicious water.
Surroundings of the water source area are surrounded by forest generally, the river flowing from the water source area has good water quality, aquatic insects living in good water quality are observed. On the other hand, however, the amount of water is decreasing overall.

The Shiribetsu River, which runs through Niseko Town, is the clearest river in the first-class river nationwide with untouched natural meandering. In the 2000 national clear stream ranking, the BOD 75% value was 0.5 mg / l, ranking second in the nation for the second consecutive year since 1999.
Among the many tributaries pouring into the Shiribetsu River, the quality of water is generally good in rivers with many natural conditions such as the Takino no Ogawa flowing from Higashiyama to Soga, the Rubeshibe River flowing from Oga flower to Miyata, the Konbu River passing through the boundary with Ranpetsu Town , Plenty of aquatic insects, fish such as Iwana, Oshokohama are also inhabited.
Even if some pollutant flows in from the basin, the ecosystem purification function maintains a good BOD value and there is no big influence on aquatic life habitat.
However, trees around the river bank are cut down everywhere, illegal dumping of garbage and abandonment of scrapped cars are seen. Also, the state of the river basin is not necessarily good, such as the fact that there are big headwinds in the upstream and the fish can not go upright.

In a river that was subjected to revetment construction by concrete such as the Kashunbeitzawa river, if it is a natural river, the function of purifying functioning sewage is significantly reduced. For that reason, the environmental impact caused by domestic wastewater and agricultural wastewater that flows in from the basin directly affects deterioration of water quality.
Especially the concrete tension of the river bed deprives the spawning place of the river fish and the habitat place of the aquatic insects, so it adversely affects the ecology of the river, causing the deterioration of water quality purification function. Kurokawa and other riverbeds are rebuilt gradually in the seawall river where only some sides do not touch. However, if you lay a stone on the riverbed, there are also places where fish can not go during the drought period.
In addition, because the surroundings are surrounded by mountainous areas and there are many steep slopes, a certain amount of headgear is necessary, but since there are many high head drops, the migratory fish can not go up and hinder natural material circulation.

Paddy fields spread in the watershed of the Rishirigawa river system, paddy fields, urban areas, hotels and pensions spread to the gentle slope of the river terrace terrace, and such land use has various influences on the river basin.
The main items of impact are various kinds of wastewater such as agricultural wastewater, agricultural waste water, livestock excrement, various illegally dumped waste, domestic waste water discharged to nearby rivers without waste, and household waste Environmental burden is pointed out.
Especially agricultural waste and household waste have a history of landfill disposal or dumping at the site or home site, and it seems that it has influenced the water system considerably. In addition, illegal dumping of waste which has been increasing in recent years not only deteriorates the water quality but also has an adverse effect on the ecosystem.