Hydrologic changes after logging in two small Oregon coastal watersheds

Effects of clearcut, cable logging on the hydrologic characteristics of a small coastal stream in Oregon indicate an average 200 percent increase in sediment yield over a 7-year postlogging period. Annual runoff and high-flow volumes increased 19 and 1.1 inches (480 and 28 millimetres), respectively, after logging in the watershed. Clearcutting in small, spaced patches in another watershed resulted in some increase in water and sediment yields, but the increase was not statistically significant. Average monthly April-October maximum water temperatures increased significantly in the principal stream of both the clearcut and "patch-cut" watersheds. Hydrologic characteristics of both streams appear to be returning to prelogging conditions.