Ipo weir, full length of 591m, consists of an operating reservoir (295m) and fixed reservoir (296m). The operating reservoir is a shell-type roller gate (which blocks the river with a bar over which water moves, and in the event of flood, the bar is lifted to make water flow) The operating weir is designed in such a way that the width and height of it can be extended from 15m(width) and 2m(height) to 45m(width) and 3m(height) to secure the stability of water management in the event of floods. Having such an excellent design, the Ipo weir won the 1st prize at an on-line weir exhibition hosted by the Office of National River Restoration. At upper side of Ipo weir, a 744m-long bridge will be built, and on the left side, a small hydro-electric power plant with capacity of 3,000kw will be built which will produce 14,532Mwh annually. On the right side, the ecological fish way with the gentlest slope (1,300mm)
in the country will be built.
