Turbidity Control Turbidity, a measure of the cloudiness of water, is typically low in the Trinity River during low flows. Permits require avoiding increased turbidity while implementing restoration actions like gravel augmentation or mechanical channel rehabilitation. Monitoring turbidity during gravel placement showed little impact on water clarity during spring high flows of up to 4,500 cfs. Also, monitoring during construction of the Sawmill site indicated that work adjacent to the channel in the riparian areas also did not affect turbidity, except for a short period during berm and turbidity curtain removal. Innovative control techniques were developed to keep turbidity impacts low.