The Department of Disaster Prevention and Mitigation reported on Monday that flooding continues to make life wretched for people in parts of Bangkok and 20 provinces, mostly in the Central Plains.
Director-general Nirat Pongsitthithaworn said the flooding resulted from accumulated heavy rainfall in many areas and runoff from the North flowing downstream to the Central Plains.
As of Monday morning, flooding still affected 2.46 million people.
In the North, flood levels were rising in Bang Rakam district of Phitsanulok and declining in Phayuha Khiri, Takhli, Banphot Pisai, Kao Liao, Muang, Chumsaeng, Tha Tako, Krok Phra and Nong Bua districts of Nakhon Sawan.
In the Central Plains, floods were declining in Uthai Thani, Lop Buri, Chai Nat, Sing Buri, Ang Thong, Ayutthaya and Samut Prakan provinces; stable in Suphan Buri, Kanchanaburi, Pathum Thani, Nakhon Pathom, Ratchaburi and Samut Songkhram; and rising in Phetchaburi.
In Bangkok, flood levels were falling.
In the East, floodwater was stable in Nakhon Nayok and declining in Prachin Buri, Chachoengsao and Chon Buri.
Deputy government spokeswoman Lalida Persvivatana said the discharge rate at the Chao Phraya River barrage in Chai Nat province had been reduced from 2,000 cubic metres per second to 1,900 on Monday.
Thanes Somboon, spokesman of the Royal Irrigation Department, said the slower discharge rate would lower flood levels in downstream provinces of the Chao Phraya River basin, namely Chai Nat, Sing Buri, Ang Thong, Ayutthaya, Nonthaburi, Pathum Thani, Samut Prakan and Bangkok.
In the East, high sea tides slowed down the drainage of the Bang Pakong River in Chachoengsao province and water-propelling boats were deployed to accelerate the drainage, he said.
In Phetchaburi province, Mr Thanes said, irrigation authorities cut the discharge rate of the Kaeng Krachan dam to limit floodwater in the centre of the province.