sheeting board; stop plank; dam board
A board used to form a temporary barrier in water channels, weirs, or construction; often part of a set of planks inserted into grooves to control water flow.
They insert stop planks into the irrigation channel to adjust the water level.
At the construction site, they assembled sheeting boards to hold back the water.
Standard kanji spelling for a board used in damming or water control.
Mixed kanji-kana spelling; common in practical or instructional contexts.
Compound of 堰 (せき, 'dam, weir') and 板 (いた, 'board, plank'). The reading せきいた is a straightforward combination of the two elements.