On 25 October 2017, NCPO leader Prayut Chan-o-cha used the extraordinary powers granted him by Section 44 of the interim constitution to issue Order Number 46/2017 to establish the Office of the National Water Resources under the Office of the Prime Minister, reporting directly to the prime minister.

[6][7] Initially, nearly 200 employees were seconded to the ONWR from the Royal Irrigation Department (RID), Agriculture Ministry, and the Department of Water Resources (DWR) from the Ministry of Natural Resources and Environment in order to begin work immediately.

After the 2011 Thailand floods, the Yingluck administration made an effort to consolidate water management in the hands of one body.

Japanese consultant Tsuruyo Funatsu had found that seven ministries and 15 agencies had a hand in water management prior to the 2011 floods, all protecting their turf and often working at cross purposes.

[11] The Thai cabinet approved a water management strategy composed of four "pillars": The ONWR was allocated a budget of 749.7 million baht for FY2019.