Publication Summary

A stream channel assessment of lower McDonald Creek was conducted to evaluate stream channel conditions before and after timber harvest activities in the watershed. Direct observation techniques were used to characterize the condition of the streambed and banks, with an emphasis on stream channel features potentially affected by changes in peak flow regimes in the drainage basin. Conditions observed in McDonald Creek over a four-year monitoring period were compared to those observed in a control stream, by scoring results from stream channel surveys and evaluating year-to-year changes observed in photo point surveys.

A stream channel assessment of lower McDonald Creek was conducted to evaluate stream channel conditions before and after timber harvest activities in the watershed. Direct observation techniques were used to characterize the condition of the streambed and banks, with an emphasis on stream channel features potentially affected by changes in peak flow regimes in the drainage basin. Conditions observed in McDonald Creek over a four-year monitoring period were compared to those observed in a control stream, by scoring results from stream channel surveys and evaluating year-to-year changes observed in photo point surveys.

Results showed evidence of effects in lower McDonald Creek that were associated with a major channel erosion event upstream of the study reach, which occurred during the first winter following the completion of timber harvest activities. These effects included extensive streambed scour and deposition of materials transported from upstream erosion sites, as well as stream channel widening. The observed changes in stream channel conditions in lower McDonald Creek are likely associated with increased peak flows. This may also be associated with sediment inputs from increased erosion in the watershed and changes in riparian conditions along McDonald Creek and its tributaries, or a combination of all of these factors.