ABSTRACT
ABSTRACT: A sand dam is a weir wall that holds a reservoir full of sediment within which water is stored. The weir is usually built in stages to trap sediments as water flows during different storms. The amount of water that can be drained depends on the characteristics of the sediments composing the sand dam. Problems associated with reduced yields of water from sand dams have been blamed on the use of high step increments during the construction of the different stages of the weirs. The effect of step height increments during construction of weirs on the water yield of sand dams has been investigated on a laboratory scale model. Other ways of trapping sediment which ensure sediment with high water storage and yield properties were also investigated. This was done by use of experimental units with different step height increments, flow rates, slopes and weir types. The main findings were that the slope, weir type and flow rates affect the storage properties of the trapped sediment, while step height increment during the different stages of construction has little effect on the properties of the sediment.
