The test will run from 9pm Thursday till 9pm Friday as part of preparations for emergency and water crisis during the 2016 dry season.
The announcement explained that its waterworks facility in eastern Bangkok might have to cut its production volume in the face of declines in available water.
Affected areas during the upcoming test include communities along two parts of Nonthaburi Road: one stretching from Bang Toranee Canal to Rattanathibet Road, and the other from Rattanathibet to Fai Jia Meng Mill.
Also affected are communities along Bang Kruay – Sai Noi Road, Ban Kluay – Sai Noi Road, Bang Bua Thong – Suphan Buri Road, Kanchanaphisek Road and Highway No 9.
MWA services cover Bangkok, Samut Prakan and Nonthaburi. More than 10 million people live in these areas.