Is the water company a state-owned enterprise or a public institution?

The company is a state-owned enterprise.

In China, most water supply companies are public institutions funded and operated by local governments or state-owned enterprises directly controlled by the government. Therefore, it is usually said that water companies are state-owned enterprises.

Tap water is an infrastructure and public enterprise, which involves people's livelihood issues. Therefore, it is usually built and operated by the government, or the government entrusts state-owned enterprises to manage and operate.