The Coon Creek Water Yield Augmentation Project: implementation of timber harvesting technology to increase streamflow

The Goon Creek pilot project represents an attempt to verify that water yield augmentation technology, demonstrated to work on small-scale experimental watersheds, could be applied at an operational or large watershed scale with similar results. Goon Creek, a 1673 ha catchment on the Upper East Fork of the Encampment River, was selected as the treatment watershed and Upper East Fork, an adjacent catchment, was selected as the control. Following an 8-year calibration period, road building and timber harvest occurred on 23.7% of the watershed area. Seasonal streamflow (April-October) significantly increased on an average 76 mm for the first 5 years after harvest. Annual peak flows, expressed as either the instantaneous maximum flow or as the maximum mean daily flow, were not significantly increased although the frequency of occurrence or duration of days of the higher, near bankful, discharges were extended. The findings at Goon Creek support and are comparable with documented observations on smaller experimental watershed studies in the cold snow zone. (C) 2001 Elsevier Science B.V. All rights reserved.