The Effect of Timber Harvest on the Fool Creek Watershed, 30 Years Later

Abstract

The Fool Creek watershed at the Fraser Experimental Forest, Colorado was harvested using a pattern of alternating clearcut and forested strips in 1956. Today, with almost 30 years of postharvest record, subtle impacts on the hydrology of the watershed can be detected that were not significant in the past. In addition to the depositional increases in the snowpack in the openings, average peak water equivalent over the entire watershed has been increased (9%). Long‐term, postharvest, climatic records now available show a strong correlation between estimated increases in flow and winter and melt period precipitation. Much of the annual variability in increased flow, now explained by precipitation, was formerly attributed to regrowth or time. Peak discharges, advanced 7.5 days following harvest, have also been increased 20%, with the largest effect occurring in the wettest years. Increases in peak water equivalent, annual flow, and date of peak flow occurrence all appear to be returning to preharvest levels at a very slow rate.