The Koshi Barrage control room said the water level started rising suddenly after 3 p.m. and reached this year´s high when measured two hours later.
Eastern Irrigation Division II in Inaruwa, Sunsari said the eastern embankment would be at risk if rainfall in the eastern hills continue through the night. [break]
"At less than 200,000 cusecs the threat of a breach is relatively low but we have to be alert if the flow crosses that mark," said engineer Kedar Tiwari.
"The Indians have also asked us not to worry until the level crosses 200,000 cusecs," he added.
The Pulthgouda region in the eastern part, considered most sensitive in the past, is facing problems even this season and India is repairing the embankments in the area.
The red light at the eastern part of the barrage was lit to indicate danger after the water flow crossed 150,000 cusecs.
The red light in the western part is lit after the level crosses 200,000 cusecs and the one in the middle after 300,000 cusec.
Thirty one out of the 56 sluice gates in the barrage have been opened following the rise in flow and more gates will be opened as required, according to the Koshi Barrage police office.
The water level was 178,000 cusecs when the embankment was breached on the eastern side on August 18, 2008. The barrage was constructed to withstand a pressure of up to 800,000 cusecs when it was completed in the early 1960s.
But if the flow were to reach 800,000 cusecs, water would overflow from both the eastern and western sides of the barrage as its capacity has been drastically reduced by massive sedimentation, experts claim.
The flow crosses 300,000 cusecs every year but it has not crossed 400,000 cusecs for a long time.
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