Monitoring of Descending Dredged Material Plumes

The physical impact of dredged material disposal on hydraulic regimes was monitored at two sites in lake Erie. The dispersing plume at one site was tracked with transmissometers; three-dimensional plots showed the plumes to decrease in intensity beyond about 100 M from the discharge point. Over-the-side current meters, thermographs, and echo sounders were utilized to monitor the plume at the second site. A 2 C temperature increase near the disposal point resulted from discharged material falling to the bottom. Sediment plumes settled quickly and ambient conditions were returned within an hour.