Streamflow changes after clear‐cut logging of a pine beetle‐infested watershed in southern British Columbia, Canada

The paired watershed technique was used to assess the streamflow changes of Camp Creek in interior British Columbia after clear‐cut logging occurred over 30% of its 33.9 km2 watershed. Existing hydrometric data for Camp Creek and those of an adjacent control, Greata Creek, were analyzed for both the 1971–1976 prelogging and 1978–1983 postlogging periods. Postlogging Camp Creek streamflow changes are characterized by increases in annual and monthly water yields and annual peak flows, as well as earlier annual peak flow and half flow volume occurrence dates. The direction and magnitude of these postlogging streamflow increases are clear and consistent. The results are in good agreement with the findings of most previous studies conducted on watersheds which generally have been smaller than 2.5 km2. This study provides strong evidence that changes in streamflow from a large forested watershed can be significant if a sizeable portion of its drainage area is clear‐cut. Possible causes for the streamflow changes are discussed.