In the river Intake, water is drawn from the upstream side to get comparatively better quality of water They are located sufficiently inside rivers so that required demand of water in met in all the seasons. It circular masonry tower of 4 to 7 m in diameter constructed along the bank of the river at such place from where required quantity of water can be obtained even in the dry period. The water enters in the lower portion of the intake known as sump well from penstocks..
Different types of river Intake:
(a)Weir Intake:This consists of a small weir constructed across the river so that even in the dry season the water level is sufficient ti feed it.The Intake water may be drawn from the weir through the channel in to a sump well from which it can be pumped to the supply.
(b)Pipe Intake:These consists of a number of pipes laid horizontally across the river. They are firmly fixed to the MMasonry blocks. The ends of the pipe are fitted with strainer.The water is drawn into a Jack well and then pumped to the purification work. This is cheap and simple arrangement.
(C)Intake well inside the river:This consists of a well made of concrete Mason which is located inside the river. A number of penstokes are located at different levels so that the water can be drawn into the well in alla season. The water is subsequently pumped to the treatment works.
(d)Intake well outside the river:In the case of a very wide river, it is impractical and not advisable to construct an Intake well in the middle of the river.Under such conditions. The well is kept outside the river and a cross approach channel is constructed to connect it to the river. The benefit is the same as in case of the well insides the river-to ensure water supply to the well even during the summer.
