Provincial governor Charnna Iamsaeng said the river had overflowed due to continuous heavy rain since Saturday and flooded several parts of the district.
The operation of pushing water towards the sea kicks off on Monday initially in Ban Na, Thung Khwai Kin and Thang Kwian subdistricts, which have been the worst hit.
Charnna added that as of Sunday evening, flooding on the Pho Thong-Ban Na Road, which connects the three subdistricts, had mostly subsided, allowing officials to distribute basic necessities among affected communities. So far, more than 2,000 survival kits have been distributed.
On Sunday, Thai Red Cross volunteers also arrived in Rayong’s Muang district and set up a cooking station to provide for flood victims evacuated from Klaeng district.
The Navy had also dispatched some 80 boats on Friday to push water from the Chao Phraya River into the sea to ease flooding in Greater Bangkok.
Vice Admiral Pokkrong Monthatpalin, Royal Thai Navy spokesman, said provincial governors can turn to the Navy for help by calling its 24-hour flood relief centre at 1696.