Hi Hussein, this is a ...

Hi Hussein, this is a recurring issue for surface water drawn in times of heavy rain where all manner of materials wash into the water body and increased stream levels (height & velocity) erode soft banks and introduce macrophytes. In general the best approach is to optimize the coagulant/flocculant dosing using jar testing. Apply the dose rates and simultaneously reduce the throughput/draw by half (doubling the retention time). Once you have achieved a satisfactory Turbidity result, incrementally increase the throughput over a couple of days to determine the optimum draw rate until the turbidity in the stream returns to normal. Best of luck, Ray