Forest Harvest Effects on Low Flow (FS-22-03)

Seasonal low flow is critical for human water supply during prolonged dry periods, and is important for aquatic biota and riparian vegetation. In some regions, such as the Pacific Northwest, this dry period coincides with the growing season when evapotranspiration rates are elevated. Understanding the influence of forest management on seasonal low flow is increasingly important with a changing climate.

This fact sheet addresses several questions:

• What effect will climate change have on surface waters?
• How does forest succession affect seasonal low streamflow?
• Which factors affect variable low flow responses?
• How may long-term climate trends interact with forest management?
• Do low flow responses persist downstream?
• Are aquatic organisms affected by long-term low flow declines?
• Will overstory thinning alleviate seasonal low flow declines?
• How may riparian buffers affect low flow responses?