The Irrigation Department has been placed on full alert over the quality of tap water in the Bangkok area, with high tides expected to raise the salinity of the lower Chao Phraya River over the next few days.
Sanya Saengphumphong, inspector-general at the Agriculture Ministry and acting director-general of the department, said the salt level had increased after high sea tides in January.
This led to difficulties with tap water production, because the salinity was above a critical level.
On Feb 13-14, high tides in the Gulf were expected to raise the water level at the mouth of the Chao Phraya River, causing an incursion ot salt water upstream, he said.
The department had since Feb 10 increased the rate of discharge of fresh water from Pasak Jolasid dam into the Chao Phraya from 55 cubic metres per second to 80, to lower salinity downstream. From the morning of Feb 14, it would be reduced to 45 cubic metres per second.
The discharge rate at the Rama VI dam hed been increased on Thursday from 45 cubic metres to 70, until the morning of Feb 16. It would then be gradually reduced to 25 cubic metres per second, to conserve the water supply.
Mr Sanya said all irrigation projects in the Chao Phraya River basin had been asked to assist in controlling the salinity level.
All sluice gates and pumping stations downstream from the Chao Phraya dam to Samlae pumping station had been told to stop pumping water during this period, to ensure the river's salinity coud be kept at the control level.
He asked for cooperation from all sectors, to use water prudently so there would be enough to last until the next wet season.