Aquaculture Engineering (2+1)

Water control structures or Gates - Main gate

Unit 11 - Water distribution and control structures

Water control structures or Gates

Main gate

The main gate connects the main channel of the pond system to the source of water. In a tide fed farm, it regulates the exchange of water. It is the biggest gate in the pond system and is usually made of reinforced cement concrete (R.C.C.). Depending upon the local site conditions and on the size of farm number of main gate may be more than one. Main gates may have one or more openings, size of each opening being usually 1 to 1.2 m in width for easy handling. A gate with wider opening will require a lifting mechanism for operation of the gate. The height of the main gate depends on the combine height of highest tide and the river flood. Generally the height of main gate is taken as that of the main or peripheral dike. It is located at a place where fresh sea water can be obtained most of the time. A typical design of main supply gate is shown in fig. The various components of the main gate are floor, apron, cut off walls, side walls, wing walls, walking plat form, flash boards and screens.