PotlatchDeltic 2022 ESG Report: Protecting Water Quality - SMZs

Sep 5, 2023 11:15 AM ET
Aerial view of a heavily forested area.

Over 50 percent of the nation’s drinking water originates from forests and timberland owners play an important role in protecting water quality. The role of water quality BMPs is to conserve and protect water quality by minimizing sediment through the filtering ability of natural vegetation and erosion control measures adjacent to water bodies. BMPs include practices such as leaving streamside management zones (SMZs) during harvest, properly designing and constructing logging roads, and using logging methods and equipment that protect water quality.

SMZs are unharvested or lightly harvested buffers that run along the length of streams and are designed to capture runoff and sediment. The SMZs provide significant other benefits, including stabilizing the banks of streams and acting as a source of food for aquatic organisms. By retaining trees alongside the streams, SMZs also shade the water’s surface from direct sunlight and significantly reduce radiative heating, keeping streams cool and clear, a particularly important objective in northern regions where cold-water fisheries are present. Riparian areas are important habitats for wildlife species and SMZs can provide wildlife with favorable habitat and travel corridors.

“Our foresters and logging contractors install SMZs along streams during harvesting and maintain them throughout the forest growth cycle. Our operational monitoring and third-party forest certification audits verify our SMZ implementation and compliance, and we are proud of the water quality protection we achieve.”

Kit Hart
Director Forest Planning and Environment,