Technical Abstract: Stream and river ecosystems have suffered extensive degradation and billions are expended annually on restoration efforts. However, few of these projects are monitored and restoration effectiveness is often unknown. Consequently, there is a poor scientific foundation for restoration designs. Since many stream restoration efforts are at least partially targeted at controlling erosion of channel banks and beds, the effects of a large-scale, long-term stream erosion control effort in 16 Mississippi watersheds was assessed using 10 to 16 years of suspended sediment and water discharge records from six of the watersheds. Seasonal Kendall tests were used to test for the presence of trends in the discharges, sediment concentrations, and flow-adjusted sediment concentration. Although sediment yields trended downward over the period of observation, water discharge was also in decline due to weather trends. Despite average expenditures for erosion control exceeding $400/ha of watershed area, flow-adjusted suspended sediment concentrations showed no project effects in five of the watersheds, and a slight reduction in one watershed. Results indicate the inability of orthodox channel erosion control structures (weirs and bank protection) to reduce watershed sediment yield and the need for a stronger scientific basis for stream restoration.