Staff at the centre said 10 tonnes of garbage was collected from canals every day and that trash often became stuck in some of the city’s 227 sluice gates and 174 water pump stations.

Littering is punishable by fines of up Bt2,000 while disposing of waste in waterways can incur a Bt10,000 penalty.

Meanwhile, a forest flood originating from a Phetchabun mountain swamped canal-side homes and hundreds of rai of rice fields in Phichit’s Thab Klo district.

Eleven homes in Ban Haen 2 Moo 3 in Nan’s Tha Wang Pha district were hit by a pre-dawn flood but damage was minimised due to advance warnings by local leaders.

In Bung Kan’s Bung Khong Long district, classrooms, a canteen and a conference hall at the 639-student Anubal Sasanasit Amnuay were hit by knee-deep flooding. Parents rushed to collect 105 kindergarten children as a precaution.

The situation was not serious enough to force a temporary closure, said school director Suparanich Udompen. Bung Khong Long mayor Cherd Saengchan said a budget of Bt300,000 had been set to dredge drainage pipes in the area to ease the flooding threat to the school in future.

Flooding since Sunday affecting 30 homes in Tambon Rangka Yai of Nakhon Ratchasima’s Pimai district and the 100-home Preeda Housing Estate in Lop Buri’s Muang district receded yesterday.

The Meteorological Department said that between yesterday and today, a monsoon trough in upper Thailand would bring continuous rain and isolated heavy rain in the North, Northeast, Central region, East and South. It also forecast two-metre waves in the Andaman Sea.

The situation would improve over five days starting tomorrow when the monsoon trough moves to Myanmar, Laos and upper Vietnam, with less rain over Thailand, the department said.