Its mission is to produce, distribute, and sell treated water in Bangkok, Nonthaburi, and Samut Prakan, and engage in related businesses synergistic with waterworks.

The new department made a survey and dug up a distributary canal of the Chao Phraya River at Sam Lae Sub-district in Pathum Thani Province to the north of Bangkok.

Returning to Thailand, he ordered the hiring of French experts to conduct a survey and make suggestions on water procurement for Bangkok.

Pipes were installed underground to distribute water throughout the Bangkok area, at a cost of over four million baht and five years of construction.

A new organization called the "Metropolitan Waterworks Authority", a public enterprise under the Interior Ministry, began operations on 16 August 1967.

[4] The MWA draws raw water from two sources: the Chao Phraya River at Ban Krachaeng Sub-district, Mueang Pathum Thani District, Pathum Thani Province and from the Mae Klong Dam in Tha Muang District, Kanchanaburi Province.