The original waterworks were constructed by the White Rajah to supply Kuching Town was situated in the Matang Hills some 12 miles from the town. The water was relatively clear and was distributed untreated. This source continued to be in use even after the Batu Kitang Plant was commissioned in 1957.

In 1960, chlorination was introduced and the possibility of building a treatment plant in the Hills was investigated.

Construction of a 2MgD treatment plant near the Matang Dam commenced in 1964 and the plant was put into operation in March 1966. Raw water from the mountain streams was piped to the plant where, full treatment, similar to that at Batu Kitang Plant was carried out before it gravitates into the distribution system.

However, production from Matang Treatment Plant was dependent on rainfall and during the dry months output may fall to as low as 10% of its maximum capacity. To improve the reliability of the water supply, work was commenced in December 1973 on the construction of a 60 million gallon earth storage basin at Matang below the Sungai Sebubut catchment. The storage basin was completed in February 1976.

With the development of the Kuching North Bank it was decided to extend the Matang Treatment Plant to increase the capacity from 2MgD to 3.5MgD. Extension works which included the construction of a 1.5 million gallon storage reservoir commenced in January 1976 and was completed in April 1977. The extension was commissioned in July 1977.

Matang Water Sources continued to be an important supply of treated water in particular to areas around Matang, which is being developed at a rapid pace. To ensure that Matang Treatment Plant can adequately sustain the reliability and meet the demands for treated water, upgrading and retrofitting works at the Matang Treatment Plant proper commenced in early January 2001 and works was completed in March 2002.

Two other upgrading works were implemented in tandem to ensure continued reliability and sustainability of Matang raw water sources were the renewal of the raw water pipeline from Sungai Cina to Matang Plant which commenced in March 2001 and the raising of the Sungai Sebubut basin catchment which commenced in January 2002 for increased live storage to 520 ML. These works were completed in July 2003 and April 2003 respectively.

Matang Treatment Plant accounts for less than 2% of the total water production for Kuching City.