State-owned enterprises and central enterprises are not juxtaposed concepts, so your question itself has problems. Central enterprises are state-owned enterprises owned by the central government and belong to a kind of state-owned enterprises. The concept corresponding to central enterprises is local state-owned enterprises. Therefore, central enterprises are small concepts, and state-owned enterprises are big concepts. Central enterprises must all be state-owned enterprises.
The controlling shareholder of Guo Zhong Water is Guo Zhong (Tianjin) Water Co., Ltd., which is a wholly-owned subsidiary of Guo Zhong Holdings Limited. Guo Zhong Holdings Limited has the ultimate control over Guo Zhong Water. Therefore, the controlling stake of China Water is not state-owned capital, state-owned enterprises, and certainly not central enterprises.