Certified Storm Water Operator Practice Exam

The size of stones in check dams should increase as slope or velocity increases to effectively manage the flow of water and sedimentation. When the slope is steeper or the velocity of water is greater, larger stones are needed to withstand the increased force of the flowing water.

Larger stones provide more resistance to erosion and are less likely to be dislodged or moved downstream by violent water flow. This helps in maintaining the integrity of the check dam and ensuring it functions as intended to slow down the water, promoting sediment deposition, and preventing excessive runoff.

In contrast, if stones were to remain the same size, decrease, or be randomized, they might not provide the necessary stability and could be easily washed away, leading to ineffective sediment control and potential failure of the dam structure. Therefore, increasing the size of the stones is a critical consideration in the design and construction of check dams in varying conditions.