The trash racks are made from steel bars at a spacing of about 5 to 15 cm c/c in both directions. The floating objects like debris, ice get collected on se racks and can be removed by manual labor as well as automatic power-driven system. The spacing depends upon maximum size of debris required to be excluded.

The seepage is reduced by increasing length of seepage path by at least 25%. The increase in seepage path must generally be greater than L/4.

A sluiceway is a pipe or a tunnel that passes through body of dam or through some hillside at one end of dam and discharges into stream below. The sluiceways are preferred to place outside limits of embankments in case of spillways.

The discharge passing through dam outlet is given by using equation-
Q = C_d. A. (2gH_L)^1/2 where C_d is coefficient of discharge = 0.62 for free over-fall, H = Water head over centre line of sluice = 330 ? 300 = 30 m and A = ?/4 x 4 = 3.14 m²
Q = 0.62 x 3.14 x (2 x 9.81 x 30)^1/2 = 47.23 cumecs.

The discharge through outlet is given by ?
Q = C_d. A. (2gH_L)^1/2 where H_L = 226 ? 210 = 16 m
Q = 0.8 x (?/4 x 16) x (2 x 9.81 x 16) = 164 cumecs.

As compared to Bell-moud or or entrance, a square edge entrance is likely to cause more separation of flow and more danger of consequent cavitation. The shape of bell-moud entrance is generally elliptical and extra cost involved I shaping this entrance is usually justified except for small projects under low heads.

Douma has suggested following equation ?
i. For circular conduits: 4X² + 44.4 Y² = d² where d is diameter of circular conduit
ii. For rectangular tunnels or conduits: X² + 10.4 Y² = d² where d is width or height of conduit depending on wher sides or top and bottom curves are being designed. Where X and Y are coordinates of any point on curve and d is width or height of conduit.

The head loss depends upon type of gate and valves. For fully open gates and butterfly valves, a loss of about 0.2 V² / 2g (where V is flow velocity through conduit) may be taken and is taken as nil for ring follower gates.

The structure may vary from a simple concrete block supporting end of conduit pipe to huge concrete towers. It is constructed at entrance of conduit. The basic function is to help in safely withdrawing water from reservoir over a predetermined range of pool levels.

The main disadvantage of simple submerged intakes is that y are not easily accessible for repairing of ir gates etc. But, se are economical and do not obstruct navigation and are widely used in small works. These are particularly suitable as water-supply intakes from small rivers.