Abstract: A fish protection system for dams comprises a series of modular units which interconnect by male and female fittings on each side of the modular unit. Each modular unit comprises a casing, an inner box and an outer box for anchoring the unit to a stream bed and side frames. A screen and cleaning mechanism can be placed within the modular units where the screens clean and direct debris and fish to a fish ladder. A cleaning comb or cutting bar moves around the modular unit such that it keeps the screens clean and directs the debris and fish to the fish ladders. The cleaning comb by use of its rounded tooth form, minimizes flow at the screen in order that fingerlings won't be harmed by the cutting edge. A fish ladder provides a constant flow by maintaining the same depth of water by a hinged ladder.