In Japan, the rainy season is usually from June to mid-July, and then the drought continues until the end of August.

In the land where the water source is uncertain, some measures have been taken such as constructing a dam. But depending on the year, water intake restrictions may be declared.

However, in Osaka, people have almost never had a problem with water. This is because Lake Biwa, which boasts the largest area in Japan, is located upstream.

Lake Biwa is located in Shiga prefecture. There are many rivers that flow into this area, but only the Seta River flows out. When entering Kyoto prefecture, it is called Ujigawa, and when entering Osaka prefecture, it is called Yodogawa.