Cutting efficiency is greatly affected by variability in soil density, hardness, lithology, and sediment particle size distribution. All of these factors create slurry of variable makeup and density. If the dredge pump works at a constant speed, the slurry will have a variable flow velocity, which is undesirable and potentially dangerous. If the velocity is too low, there is a risk of sandouts in the pipeline. If the velocity is too high, the pump will wear and be inefficient. Traditional velocity flowmeters with wetted parts are prone to wear, causing measurement inaccuracies, and require frequent, costly replacements.